What Is Pulmonary Vasculitis?

Vasculitis is a group of diseases whose main pathological manifestations are inflammatory changes in the blood vessel wall. Vascular inflammation can cause blood vessel destruction, so it is sometimes called necrotizing vasculitis. Vasculitis includes a wide range of diseases, which can be either primary vasculitis, or can be accompanied or secondary to other diseases. The invading blood vessels are mainly arteries, which can also involve arteries, veins and capillaries. Small blood vessels can be the main invasion object, or diseases with large blood vessels as the main invasion. Pulmonary vasculitis, as the name implies, refers to vasculitis in which the pulmonary blood vessels are invaded. Some pulmonary vasculitis is relatively rare, and the diagnosis is difficult, which should cause sufficient attention in the clinic. At the Chapel Hill conference in the United States in 1994, a series of nomenclature and classification criteria for primary vasculitis were summarized after careful discussions from 6 different countries, different centers, and different professional scholars. Swollen small vasculitis involves the upper or lower respiratory tract, with or without necrotizing glomerulonephritis, and does not have anti-renal basement membrane antibodies or immune complexes. It is recommended to use this diagnosis There is one polyangiitis under the microscope (polyarteritis under the microscope), because the pulmonary vasculitis in these patients is mainly necrotizing alveolar capillary inflammation.

Basic Information

English name: Pulmonary Vasculitis
Visiting department: Respiratory Medicine

Common causes: Unknown cause
Common symptoms: Systemic symptoms include fever, fatigue, joint pain, and skin lesions. Granulomatous vasculitis may have difficulty breathing, coughing, etc.

Etiology and classification of pulmonary vasculitis

The cause is unclear. Shortly after the Chapel Hill meeting, Lie proposed a new classification, because this classification is relatively simple and practical, and will briefly introduce the clinical characteristics of various pulmonary vasculitis.

Primary vasculitis

(1) Affect large, medium and small blood vessels: Takayasu vasculitis. Giant cell (temporal) arteritis. Central nervous system limited vasculitis.

(2) Affects medium and small blood vessels: Nodular polyarteritis. Allergic granulitis vasculitis. Wegener's granuloma.

(3) Mainly affect small blood vessels: Polyangiitis under the microscope. Allergic purpura. skin leukocyte fragmentation vasculitis.

(4) Others: Behcet syndrome. Burger's disease. Cogan syndrome. Kawasaki disease.

2. Secondary vasculitis

(1) Infectious vasculitis.

(2) Vasculitis following connective tissue disease.

(3) Vasculitis caused by (allergic) drugs.

(4) Secondary to mixed primary cryoglobulinemia.

(5) Vasculitis associated with cancer.

(6) Urticaria hypocomplementemia vasculitis.

(7) Vasculitis after organ transplantation.

(8) Pseudoangiitis syndrome (myxoma, endocarditis, Sneddon syndrome).

Pulmonary vasculitis epidemiology

Pulmonary vasculitis is not common in clinical practice. Wegener's granulomatosis is more common in connective tissue diseases. As of 1967, 200 cases were reported in various countries. Peking Union Medical College Hospital only found more than 20 cases by 1999. The prevalence is unknown.

Pulmonary vasculitis can be found at all ages, but some specific diseases have age and gender tendencies. Such as allergic purpura is more common in young children; granulomatous vasculitis is more common in middle-aged and elderly people aged 50 to 60; and connective tissue disease secondary vasculitis is more common in women of childbearing age. Wegener's granulomatosis and Churg-Strauss syndrome are predominantly male.

Pathogenesis of pulmonary vasculitis

Pulmonary vasculitis is characterized by the inflammatory reaction of the vascular wall, which often runs through the entire layer of the vascular wall, and often uses blood vessels as the center of the disease. The tissues surrounding the blood vessels can also be affected, but bronchial central granulomatosis is an exception. Both large and small arteries and veins can be involved, and capillary inflammation can also occur. Inflammation is often accompanied by fibroid necrosis, intimal hyperplasia, and perivascular fibrosis. Therefore, pulmonary vasculitis can lead to occlusion of blood vessels and produce occlusive vascular disease. The inflammatory response cells include neutrophils, normal or abnormal lymphocytes, eosinophils, monocytes, macrophages, histiocytes, plasma cells, and multinucleated giant cells, and many of them are mixed. For example, when neutrophils are predominant, leukocyte fragmentation vasculitis appears; when lymphocytes are predominant, it is the main manifestation of granulomatous vasculitis. However, the number of infiltrating inflammatory cells will vary with different stages of vasculitis. For example, a large number of lymphocytic infiltration will occur after the acute phase of leukocyte fragmenting vasculitis, and in the late stage of granulomatous vasculitis, inflammatory cells may be mononuclear cells, histiocytes, and multinucleated giant cells, not lymphocytes.

Although the clinical and pathological manifestations of pulmonary vasculitis may be different, they all share common immunopathology. Studies in the past decade have found that antineutrophil cytoplasmic antibodies (ANCA) play an important role in the pathogenesis of vasculitis.

ANCA includes two broad categories:

1.C-ANCA (cytoplasmicstainingpatternofANCA) mainly binds to proteinase3 (PR3) in primary particles in neutrophils, monocytes and immature macrophages. In the process of alcohol fixation, the primary particles rupture and PR3 is released. Because of its poor charge, indirect immunofluorescence staining appears as a coarse particle-like cytoplasmic staining type.

2.P-ANCA (perinuclearstainingpatternofANCA), which mainly targets serine proteases such as myeloperoxidase (MPO), elastin, lactoferrin and other components in the particles. These components have positive charges. In indirect immunofluorescence staining, With the rupture and release of particles, it is easy to combine with the negatively charged cell nucleus, showing a perinuclear type, P-ANCA is named after this. It has been found that C-ANCA for PR3 can be detected in the serum of many patients with active Wegener's granulomatosis and has high specificity. The C-ANCA titer of some patients is positively correlated with disease activity. P-ANCA for MPO is more common in systemic necrotizing vasculitis including Churg-Strauss syndrome, microscopic polyangiitis, and idiopathic and drug-induced glomerulonephritis. Atypical P-ANCA for other ingredients can occur in many diseases such as inflammatory bowel disease, inflammatory liver disease, connective tissue disease, chronic infection, HIV infection, rheumatoid arthritis, and even a small part is normal Can also appear in people. Sometimes indirect immunofluorescence staining of ANA can also show a P-ANCA-like staining phenotype, which is mistaken for P-ANCA positive. Therefore, when evaluating the positive results of P-ANCA, specific analysis must be performed in conjunction with the antigens and clinical manifestations that they target. In many cases, atypical P-ANCA only indicates the existence of a chronic inflammatory response and is not specific for the diagnosis of vasculitis.

ANCA antigens are mostly neutrophils used as bactericidal components in host defense responses. However, it is not clear why immune responses are directed against these autoantigens and what role infections play in them. Indeed, repeated bacterial infections can lead to exacerbation of vasculitis; and the state of S. aureus in patients with vasculitis can cause recurrence of vasculitis. There is evidence that compound neonomine is effective in treating localized Wegener's granulomatosis, and it can reduce relapse in patients with multiple system involvement.

There are several hypotheses for the pathogenesis of ANCA in vasculitis. One theory is that some pro-inflammatory factors such as IL-1, TGF-, TNF, or pathogenic components can stimulate neutrophils, causing some components in the cytoplasmic particles to shift to the cell surface and become targets for ANCA attacks. These cytokines also cause endothelial cells to overexpress adhesion factors. ANCA can also induce neutrophils to release reactive oxygen free radicals and lysosomal enzymes, resulting in local endothelial cell damage. These neutrophils can penetrate damaged endothelial cells and gather around blood vessels. It is also thought that vascular endothelial cells themselves can express ANCA antigen.

In short, ANCA can promote the adhesion of neutrophils to vascular endothelial cells, indirectly lead to endothelial cell damage, promote the displacement of neutrophils, and enter the tissues around the blood vessels.

In addition, some studies have shown that the formation and deposition of pathogenic immune complexes is also an important cause of vascular inflammation. Other mechanisms such as direct infection of endothelial cells, the presence of anti-endothelial antibody, and HLA-dependent T cell-mediated endothelial cell damage are also involved in the pathogenesis of vasculitis. Different vasculitis syndromes are caused by different types of endothelial cell response, different immunopathological mechanisms, and different vascular characteristics.

Clinical manifestations of pulmonary vasculitis

Systemic symptoms of pulmonary vasculitis include fever, fatigue, joint pain, and skin lesions, especially in patients with systemic vasculitis and connective tissue disease. Granulomatous vasculitis may present with symptoms such as dyspnea and cough. Wegener's granulomas and lymphoma-like granulomas can cause hemoptysis, especially in patients with pulmonary aneurysms or diffuse capillaries. Churg-Strauss syndrome is often accompanied by recurrent dyspnea and asthma.

1. Affect large, medium and small blood vessels

(1) Temporal arteritis is also called giant cell arteritis.

(2) Takayasu disease is also known as polyarteritis .

Pulmonary artery involvement is more common, with reports of up to 50%, which can be associated with pulmonary hypertension, and can also show significant clinical manifestations, such as hemoptysis and chest pain. Studies have shown that, even in patients without obvious symptoms of the lung, pulmonary biopsy and angiography also show pulmonary artery involvement.

2. Mainly affects medium and small blood vessels

(1) Nodular polyarteritis is a systemic disease involving multiple systems. The main pathological manifestations are infiltration of neutrophils in the small and medium muscular arteries, with intimal hyperplasia, fibroid necrosis, vascular obstruction, and aneurysms. Formation, etc., resulting in ischemia and infarction of the affected tissue. Involvement of joint muscles, liver and mesenteric blood vessels, testes, peripheral nervous system and kidneys is more common. There have been different opinions on whether the lungs and their blood vessels are involved. Most opinions currently suggest that nodular polyarteritis rarely affects the lungs. Therefore, if there is evidence of pulmonary vascular involvement, it should be distinguished from microvasculitis, Churg-Strauss syndrome, and Wegener's granulomatosis.

(2) Churg-Strauss syndrome is also called allergic granulomatous vasculitis. It was named after Churg and Strauss first reported in 1951. It is a systemic disease mainly characterized by asthma, eosinophilia, and granulomatous vasculitis. It is more common in middle-aged men with a history of asthma and asthma symptoms. Lungs, peripheral nerves, heart, and skin are more commonly affected. Renal involvement is reported rarely and the lesions are mild. Eleven cases have been reported in China so far, and there are 6 cases confirmed by pathology in a hospital in Beijing. Renal involvement is not uncommon, reaching more than 50%, and renal insufficiency may occur. In addition to the asthma manifestations, the lung manifestations of Churg-Strauss syndrome may also include cough and hemoptysis, and flaky infiltrates or nodules can be seen on chest imaging. Churg-Strauss progresses quickly without treatment. Active adrenocortical hormone combined with immunosuppressive therapy is effective.

(3) Wegener's granulomatosis was first reported by Wegener, hence its name. Its clinical manifestations are mainly necrotizing granulomatous vasculitis and glomerulonephritis of the upper and lower respiratory tract, which can also affect the eyes, ears, heart, skin, joints, and peripheral and central nervous systems. If there is only upper and lower respiratory tract involvement without kidney involvement, localized Wegener's granulomatosis is called. The etiology is unknown, but Wegener's granulomatosis is often associated with hypergammaglobulinemia and ANCA positive, and is effective for cytotoxic drug treatment, indicating that immune mechanisms are involved in the pathogenesis. Wegener's granulomatosis can develop at any age, but is more common in middle-aged men. Lung disease can be mild or severe, and severe can be fatal. Two-thirds of patients may have chest X-ray abnormalities, which may involve unilateral or bilateral involvement. The main manifestations are pulmonary infiltrates or nodules, and some with cavities. Because bronchiopathy can cause atelectasis, pleural thickening and pleural effusion can also occur. Pathological biopsy often manifests as lung tissue necrosis with granulomatous inflammation. Infiltrating cells include neutrophils, lymphocytes, plasma cells, eosinophils, and tissue cells. Vascular inflammation can lead to vascular obstruction and infarction; 1/3 of patients can appear Symptoms of hemoptysis in pulmonary capillary vasculitis. In addition, some patients may develop pulmonary interstitial fibrosis, acute and chronic bronchiolitis, occlusive bronchitis, and so on. A large number of clinical studies have shown that ANCA, especially C-ANCA for PR3, although it can be seen in other vasculitis, can occur in more than 80% of Wegener's granulomatous disease course, and continuous high density often indicates disease activity. The titer of the disease can also decrease, which can be used as an important indicator for monitoring Wegener's granulomatous disease activity. With the application of cytotoxic drugs, especially cyclophosphamide, the mortality rate of Wegener's granulomas has decreased significantly. The dose of cyclophosphamide is generally 1-2 mg / (kg · d), and it can also be 2-4 mg / (kg · d) It is given once every other day, mostly in combination with corticosteroids. The course of treatment is at least 1 year, and can be gradually reduced in the future. It has also been reported to maintain methotrexate. For some patients who have an infection cause or are prone to relapse, compound Xinnuomin can be added. Studies have shown that it can reduce relapse.

3. Mainly affect small blood vessels

(1) Polyangiitis under the microscope Polyangiitis under the microscope is an independent vasculitis isolated from nodular polyarteritis. Its clinical manifestations are inflammation of necrotizing arterioles, venules, and capillaries, which mainly affect the kidneys, skin, and lungs, and are often accompanied by ANCA positive. The affected vessels have no or little immune component deposition. Involved blood vessels can appear cellulosic necrosis and infiltration of polymorphonuclear leukocytes and monocytes, which can be associated with thrombosis. The kidneys appear as focal segmental glomerulonephritis, sometimes with crescent formation; lung involvement is manifested as necrotizing pulmonary capillary vasculitis, with little immunoglobulin and complement deposition. The disease is common in the elderly and slightly more men. At the time of onset, it is usually accompanied by systemic symptoms such as fatigue, weight loss, fever, and joint pain. Renal involvement is common and manifests as proteinuria, hematuria, or cell casts; many patients present with rapidly progressive glomerulonephritis.

(2) Henoch-Schënlein purpura. It is common in children and affected in adults. It is a type of leukocyte fragmenting vasculitis. It is often accompanied by a pre-infection of the upper respiratory tract, followed by purpura of hips and lower limbs, arthritis, and abdominal pain. Some patients may also have microscopic hematuria and glomerulonephritis. Respiratory tract involvement is relatively rare and can be manifested as alveolar hemorrhage and lamella infiltrates around the hilar, serum IgA can be elevated, and IgA deposition can also be seen on tissue biopsy immunofluorescence.

4. Behcet syndrome

Behcet syndrome can involve both large and small blood vessels; it can affect both arteries and veins. Its clinical manifestations are recurrent oral painful ulcers and perineal ulcers, which can be associated with joint pain, erythema nodules or pustular papules, venous thrombophlebitis of the lower limbs, and uveitis, and can also affect the digestive tract, cardiovascular, Nervous system, kidneys, and lungs. Active patient

Positive acupuncture reactions may occur. IgG and complement deposition can occur in the affected area, and pulmonary involvement can occur in 10% of patients, with recurrent pneumonia and hemoptysis, and sometimes fatal hemoptysis. The cause of hemoptysis may be due to pulmonary vasculitis or ruptured bronchi veins, or it may be caused by ruptured pulmonary aneurysms or arteriovenous fistulas. Patients with important organs such as the eyes, nervous system, digestive tract, and lungs of Behcet syndrome should be treated with active immunosuppressive agents. Symptomatic hemoptysis surgery is not effective and is prone to recurrence or new aneurysms.

5. Vasculitis secondary to connective tissue disease

(1) Systemic lupus erythematosus Systemic lupus erythematosus lung involvement is mainly manifested by pleurisy, pleural effusion, but also atelectasis, acute lupus vasculitis, diffuse interstitial lung disease, and vasculitis. Pulmonary vasculitis is mainly a type of leukocyte fragmenting vasculitis that can be associated with fibroid necrosis, but the specific incidence of lupus erythematosus has been reported differently. Pulmonary hypertension can occur in some patients, mostly mild-to-moderate.

(2) In addition to joint involvement, rheumatoid arthritis can also manifest vasculitis. Pulmonary involvement is often manifested as pleurisy or pleural effusion, intrapulmonary nodules, and pulmonary interstitial disease. Pulmonary vasculitis and pulmonary hypertension may occur in some patients, but the incidence is low.

(3) The main clinical manifestations of systemic sclerosis are finger sclerosis and skin sclerosis of the trunk and extremities. Patients are often accompanied by obvious Raynaud's phenomenon and pulmonary interstitial disease with pulmonary hypertension. Intimal hyperplasia of arterioles and arterioles can occur, and concentric fibrosis can cause arteriolar stenosis and occlusion. But inflammatory cell infiltration and fibroid necrosis are not common. Therefore, strictly speaking, it cannot be called vasculitis. Most of the hormone and immunosuppressive treatments are not effective.

(4) Sjogren's syndrome is an autoimmune disease mainly involving the exocrine glands. Epidemiological data abroad and at home indicate that Sjogren's syndrome is not a rare disease. Some people call it autoimmune epitheliitis because it can not only affect salivary glands and cause dry eyes, but also involve renal tubular epithelium and cause renal tubular acid Poisoning involves gastrointestinal symptoms caused by hepatobiliary epithelium, pancreatic duct epithelium, and gastrointestinal glandular epithelium, and pulmonary bronchiolar epithelium causes pulmonary interstitial fibrosis and pulmonary hypertension. Sjogren's syndrome vasculitis and hypergammaglobulinemia are also important pathogenic mechanisms of pulmonary interstitial fibrosis and pulmonary hypertension. Treatment emphasizes early corticosteroids and immunosuppressive therapy in the early stages of pulmonary interstitial lesions.

6. Cryoglobulinemia

Recurrent purpura, joint pain, and involvement of the kidneys and other internal organs, accompanied by an increase in serum cryoglobulin content and a positive rheumatoid factor are clinical features of the disease. Leukocyte infiltrating vasculitis, immunoglobulin and complement deposition on the vessel wall are its histological features. The lung can also be invaded and often manifests as diffuse interstitial infiltration, and the pulmonary blood vessels also exhibit the above-mentioned inflammatory changes.

7. Other occasional pulmonary vasculitis

These diseases are mainly lung diseases, and may also show the manifestation of pulmonary vasculitis.

(1) Lymphoma-like granulomatosis is a vascular-centric granulomatous disease in which the lungs are invaded without exception. It was first described by Liebow et al. In 1972. Histomorphology is mainly manifested as destructive invasive lesions in the upper and lower respiratory tract, skin, and central nervous system with blood vessels as the center. Infiltrating cells are mainly lymphoblasts, plasma cells, histiocytes, and atypical large lymphocytes that contain abnormal mitotic figures, and form granulomatous lesions. Untreated lymphoma-like granulomas generally deteriorate rapidly and eventually die from central nervous system disease. About half of the patients may be relieved by cyclophosphamide and corticosteroid treatment. The average survival time is 4 years. When the treatment cannot be relieved, they will develop angiocentric T-cell lymphoma. However, there may be benign types. The latter is mainly manifested by pleomorphic lymphocytic invasion of vasculitis and granulomatous formation, rarely tissue necrosis, and good response to treatment. It was also known as "lymphocytic vasculitis and granulomatous" disease".

(2) Necrotizing sarcoidosis-like granulomatosis was first reported by Liebow in 1973. Its histological characteristics are granulomatous lesions fused in the lung, which are similar in appearance to sarcoidosis, but with necrotizing granulomatous vasculitis lesions of the pulmonary arteries and veins, and about half of the patients are not associated with hilar lymphadenopathy, and Typical sarcoidosis is different. The prognosis of the disease is good, and it can often be relieved naturally. The disease may be a variant of sarcoidosis.

(3) The clinical symptoms of bronchocentric granulomatosis may include fever, fatigue, cough, asthma, etc. The eosinophil count can increase, the chest X-ray film shows infiltrative or nodular shadows, and atelectasis can also occur. Different from other systemic vasculitis diseases, there is no multi-organ involvement. Half of the patients are related to contact with Aspergillus or other fungi; the lungs are centered on the bronchus, and the small airways are destroyed by the infiltration of lymphocytes and plasma cells. Basic histological changes, the small arteries and veins near the lesion can be violated, so pulmonary vasculitis is a secondary pathological process. The prognosis is better, it can be relieved naturally, only symptomatic treatment is needed, and those with severe symptoms need corticosteroid treatment.

Pulmonary vasculitis signs

Signs are associated with affected organs. Such as leukocyte fragmentation vasculitis has more obvious rashes and ulcers, and joint deformation indicates the presence of rheumatoid arthritis. Nasal and upper respiratory tract ulcers may indicate the presence of wegener granulomas or lymphoma-like granulomas. The former can also cause ptosis, keratitis, and uveitis. Behcet syndrome is often accompanied by oral, perineal painful ulcers and uveitis. Nodular polyarteritis and Churg-Strauss syndrome often involve peripheral nerves, while giant cell arteritis may early show signs of central nervous system involvement. The signs of the lungs also vary depending on the extent of the lesion. Complications: Pulmonary vasculitis can be complicated by multiple system and multiple organ damage.

Pulmonary vasculitis examination

Laboratory inspection

Orthocytic anemia, thrombocytosis, increased polyclonal r globulin, decreased albumin levels, increased ESR, increased CRP, and abnormal liver enzymes all indicate acute phase reactions to inflammation.

2. Other auxiliary inspections

Angiography showed that the lumen was irregular, the lumen was narrowed and occluded, and the lumen was dilated like a tumor. In addition to ultrasound diagnosis of cardiovascular disease, imaging can also find lesions such as thickened blood vessel walls and narrowed lumen. X-ray tomography in imaging can also find thickening of the blood vessel wall and stenosis of the lumen. Magnetic resonance imaging in imaging can also detect thickening of blood vessel walls and stenosis of the lumen.

Pulmonary vasculitis diagnosis

In all vasculitis, there are more or less skin lesions, systemic and muscular joint symptoms, and laboratory tests show some abnormal inflammatory response indicators. These abnormalities should be noted to rule out vasculitis. Systemic symptoms of vasculitis include fever, anorexia, weight loss, and fatigue. Muscle and joint symptoms include rheumatic polymyalgia-like symptoms, joint pain or arthritis, myalgia, and peripheral neuropathy.

Laboratory tests often show orthocytic anemia, thrombocytosis, decreased albumin levels, increased polyclonal r globulin, increased ESR, increased CRP, and abnormal liver enzymes, all of which indicate an acute phase response to inflammation. To diagnose vasculitis, it is necessary to have a full understanding of the clinical manifestations of different vasculitis, diagnose the clinical, laboratory, histopathological or angiographic abnormalities of specific patients, and pay attention to differential diagnosis with some secondary vasculitis. Vasculitis is diagnosed by biopsy or angiography. Whenever possible, these tests should be performed to clarify the diagnosis of vasculitis. Because once vasculitis is diagnosed, long-term treatment is often required, and there are many toxic and side effects of treatment drugs.

In general, biopsy should be performed on the symptomatic and easy-to-access parts, and the positive rate of blind tests on asymptomatic parts such as muscles, testes or nerves is low. Biopsy of skin, muscle, nasal mucosa and temporal artery is well tolerated and easy to obtain. Although there is no specific skin biopsy for the diagnosis of a vasculitis, the combination of clinical, laboratory and radiological findings can often make a diagnosis of vasculitis. Testicular involvement is rare and general anesthesia is required for testicular biopsy, which is sometimes difficult for patients to accept. If the patient has clinical manifestations of neuropathy or abnormal measurement of electromyography and nerve conduction velocity, a gastrocnemius nerve biopsy is very helpful, but biopsy often has the sequelae of local sensory disturbance in the distal lower extremity. Percutaneous renal biopsy is not dangerous, but vasculitis is less common. The most common histopathological manifestation is focal segmental necrotizing glomerulonephritis. For the diagnosis of pulmonary vasculitis, the positive rate of bronchoscopic lung biopsy is not high, and open chest biopsy or thoracoscopy lung biopsy should be performed.

For suspected vasculitis but no suitable biopsy site, angiography should be performed. Vasculitis angiography is typically manifested as segmental arterial stenosis, sometimes with cystic aneurysm-like dilatation and occlusion. Abdominal angiography is generally used, and sometimes there are abnormalities even though there is no abdominal angiography, and abnormalities can occur in the kidney, liver and mesenteric blood vessels. The presence of cystic aneurysm on angiography is more serious. Effective treatment can reverse angiographic abnormalities. However, the specificity of angiography is not high. Many vasculitis and secondary vasculitis can cause similar angiographic abnormalities, such as nodular polyarteritis, Wegener's granulomatosis, Churg-Strauss syndrome, and rheumatoid arthritis. And systemic lupus erythematosus vasculitis and Behcet's syndrome. In addition, other diseases such as left atrial myxoma, bacterial endocarditis, thrombotic thrombocytopenic purpura, abdominal tuberculosis, arterial dissection, tumors, and pancreatitis can cause abnormal angiography. In giant cell arteritis, Takayasu arteritis, and Buerger disease, the angiography has certain characteristics, the distribution of affected blood vessels is different, and there is no cystic aneurysm.

Differential diagnosis of pulmonary vasculitis

Infectious vasculitis

Vasculitis-like manifestations can be caused by many different pathogenic infections, including bacteria (such as Streptococcus, Staphylococcus, Salmonella, Yersinia, Mycobacterium, Pseudomonas, etc.), fungi, rickettsia, Burdell's Borrelia and viral infections (such as hepatitis A, B, C virus, cytomegalovirus, EB virus, shingles virus, HIV virus, etc.) are mostly easy to identify based on their clinical manifestations and corresponding laboratory tests. Most of the hypersensitive vasculitis caused by infectious diseases are skin lesions.

2. Tumor or connective tissue disease secondary to vasculitis

When patients have vasculitis-like manifestations (especially skin lesions), if they are accompanied by hepatosplenomegaly, lymphadenopathy, reduced cells, or abnormal peripheral blood smears, care should be taken to exclude the possibility of secondary vasculitis of the tumor. . Lymphoma, leukemia, and reticular endothelial hyperplasia tumors are prone to this manifestation, while solid tumors are relatively rare. In addition, some connective tissue diseases may also appear secondary vasculitis, common: rheumatoid arthritis, Sjogren's syndrome, and systemic lupus erythematosus, which need to be identified.

Pulmonary Vasculitis Treatment

The treatment of pulmonary vasculitis is mostly the same. Regardless of its etiology or its limitation to the lungs or as part of a systemic disease, glucocorticoids and cyclophosphamide are still the main drugs for treatment.

Glucocorticoids can be taken orally with prednisone (prednisone), or methylprednisolone (methylprednisolone) intravenously, for 3 to 5 days, and then changed to the above dose of prednisone (prednisone) orally. In the future, it will be gradually reduced to the withdrawal within 2 to 6 months according to the treatment response. Cyclophosphamide is usually taken orally for 6 to 12 months and then gradually discontinued within a few months. In patients who require mechanical ventilation due to respiratory failure, cyclophosphamide can be given intravenously. Pneumocystis carinii pneumonia can develop in about 20% of patients in this treatment regimen, so prophylactic use is recommended, and sulfamethoxazole / trimethoprim (SMZco) is applied 3 days a week. Prolonged cyclophosphamide treatment often increases the incidence of side effects, such as infections, hemorrhagic cystitis, bladder tumors, and bone marrow suppression.

Azathioprine and methotrexate are suitable for those who cannot tolerate cyclophosphamide, but there are only few data showing their long-term efficacy. Plasma exchange is recommended for patients who do not respond to cytotoxic and immunosuppressive drugs. This method has a positive effect on Good-Pasture syndrome, especially those with diffuse alveolar hemorrhage, but the effect on systemic vasculitis is uncertain, and data must be accumulated to observe its effect.

IVIG was tested on typical WG patients, but the results were inconsistent.

Other measures, such as human monoclonal antibodies directed against specific lymphocyte subsets, were tested in patients with WG who were ineffective or intolerant to conventional treatment.

LYG hormones and immunosuppressive agents are available for trial, often with poor response, and localized lesions can be treated with radiotherapy or surgery.

Prognosis of pulmonary vasculitis

The prognosis of pulmonary vasculitis is related to different disease types. Generally, the prognosis of CSS, NSG and BG is good, and the survival of WG after hormone + CTX treatment is significantly prolonged, but LYG treatment has some difficulties and the prognosis is poor.