What Is Monoclonal Gammopathy?

Monoclonal gamma globulin disease with peripheral neuropathy is also known as paraproteinemia peripheral neuropathy. When there is too much M protein in the blood, it is called monoclonal glycinopathy, also known as immunoglobulin disease, paraprotein disease, or plasma cell disease. The pathological significance of the presence of M protein in the blood on peripheral nerves is that the M protein contains one or more antibodies against myelin or axon membranes, such as anti-MAG, GM ₁ and GD ₁ antibodies. Of the idiopathic peripheral neuropathies of unknown cause, 10% are associated with monoclonal globulopathy, and 29% to 71% of MGUS are associated with peripheral neuropathy, suggesting monoclonal globulopathy Related to peripheral neuropathy.

Basic Information

nickname

Paraproteinemia peripheral neuropathy

Visiting department

Neurology

Multiple groups

People over 50

Common causes

Caused by abnormal proliferation and secretion of immunoglobulin by monoclonal plasma cells derived from immune B cell lines

Common symptoms

Numbness of feet, paresthesia, impaired balance and gait instability, etc.

Causes of monoclonal gamma globulin disease with peripheral neuropathy

Monoclonal gamma globulin disease, immunoglobulin disease, paraproteinemia, and endoprotein abnormalities. This group of diseases is also known as plasma cell disease. It is a group of tumorous or tumor-prone diseases. Monoclonal plasma cells of immune B cell lines are caused by abnormal proliferation and secretion of immunoglobulins. Peripheral nerve myelin sheath is composed of a variety of glycolipids and glycoproteins, of which glycosphingolipid and myelin-associated protein (MAG) are considered to be antigens related to immune-mediated peripheral neuropathy.

Clinical manifestations of monoclonal gamma globulin disease with peripheral neuropathy

There are two groups of clinical symptoms and signs, that is, the manifestations of multi-system lesions caused by monoclonal glycinopathy, and the manifestations of peripheral motor and sensory autonomic dysfunction due to peripheral nerve damage. This is one of the clinical features of this disease.

MGUS or benign monoclonal glycinopathy combined with peripheral neuropathy is mainly seen in patients over 50 years of age. It is a hidden attack. It is more common in symmetric polyneuropathy, which is mainly manifested by numbness of the feet, paresthesia, impaired balance and gait instability. The symptoms of tactile sensation and tactile involvement are obvious, and half of the patients have pain and discomfort. The course of the disease often lasts for several years to decades. In the late stage, there are symptoms of motor nerve involvement such as weakness of the distal lower limbs and varying degrees of atrophy, but it is rare that the muscle weakness causes the bedridden. A small number of patients can present with simple motor neuropathy, which is similar to the performance of motor neuron disease.

Examination of monoclonal gamma globulin with peripheral neuropathy

Laboratory inspection

(1) Serum protein electrophoresis For unidentified idiopathic peripheral neuropathy, serum protein electrophoresis and immunoelectrophoresis should be routinely performed to detect the presence of M protein.

(2) Although the periprotein in urine is sometimes negative for M protein in serum, the light chain of M protein can enter the urine called periprotein, and urinary periprotein has the same clinical significance as serum M protein. Therefore, the urine test must be performed simultaneously with the serum.

(3) Cerebrospinal fluid protein often increases.

(4) An increase in plasma cells can be seen in bone marrow aspiration , which can be heterotypic or naive.

2. Other auxiliary inspections

(1) Electrophysiological examination of the electromyogram shows that the distal conduction velocity of the peripheral nerve symmetry is slowed down, mainly due to sensory involvement, and the distal motor latency is prolonged. In severe cases, conduction block and waveform dispersion can be seen, as well as reduced amplitude. Axon involvement.

(2) Relevant examination of monoclonal gamma globulin, urocoagulin, and cerebrospinal fluid.

Diagnosis of monoclonal gamma globulin disease with peripheral neuropathy

1. Peripheral neuropathy, dyskinesia and other clinical manifestations.

2. For unexplained idiopathic peripheral neuropathy, urine and serum protein electrophoresis and immunoelectrophoresis should be routinely performed to detect the presence of M protein.

3. Cerebrospinal fluid protein often increases.

4. Electrophysiological examination may have limited motor conduction block.

5. If necessary, the gastrocnemius nerve biopsy can show segmental demyelinating or axonal mutation.

Differential diagnosis of monoclonal gamma globulin disease with peripheral neuropathy

The relationship between monoclonal globulinopathy peripheral neuropathy and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and multifocal motor neuropathy has not yet been determined. The clinical manifestations and electrophysiological characteristics of CIDP and some types of monoclonal globococcal peripheral neuropathy are very similar, and both have elevated cerebrospinal fluid proteins, and 1/4 of CIDP can be combined with monoclonal globococci disease. GM ₁ antibodies can be detected in the serum of 20% to 84% of patients with multifocal motor neuropathy, of which 20% are monoclonal and the rest are polyclonal. It is speculated that CIDP and multifocal motor neuropathy may have common pathophysiological mechanisms with monoclonal globulinopathy peripheral neuropathy.

Monoclonal gamma globulin disease with peripheral neuropathy

1. Treatment of malignant monoclonal gammaglobulin peripheral neuropathy.

2. In benign monoclonal globulin disease, patients with IgG and IgA type M protein are effective for high-dose immunoglobulin therapy, and their symptoms are improved after several days or weeks of administration.

3. Plasma exchange, steroids and other immunosuppressive therapies can also achieve certain effects. The immunoadsorption method can remove IgG antibodies and complement from the blood, but it may cause a transient exacerbation of the disease, which must be performed once a month.

4. IgM-type benign monoclonal globococci disease has a poor therapeutic effect on immunosuppressive drugs, and a sufficient amount of cyclophosphamide or chloroquine must be used to reduce the M protein to a certain level before clinical improvement can be achieved.