Heavy chain disease

Heavy chain disease (BTC) - A rare disease. Think, that it is based on immunoglobulin synthesis anomaly, caused by a somatic mutation of the cells with the loss of part of its structural genes, responsible for the synthesis of the heavy chains. As a result, only fragments secreted heavy chains of different classes BTC belong to the group of tumor B-lymphoproliferative disease with various clinical and morphological manifestations. Različaût BTC-γ, -a, -m и -S.

Heavy chain disease-γ

This form of the disease has been described in Franklin 1963 city, therefore it is also called Franklin disease. It occurs in people under the age of 40 years.

The clinical picture of the disease recalls malignant lymphoproliferative processes. The most common symptom is localized or generalized lymphadenopathy, spleen, liver.

In addition to progressive anemia, observed in patients with thrombocytopenia and leukopenia with relative lymphocytosis. Among the lymphocytes there are atypical forms, and plasma cells. Often (about 30 % cases) observed eosinophilia. We describe two cases BTC-γ with a picture of plasma cell leukemia.

Tumor proliferation in the bone marrow are rarely observed. When present, the bulk of the cells comprise lymphocytes and plasma cells, but it can also detect eosinophilic granulocytes and reticular cells. ESR normal or increased. M gradient serum revealed changeably. Content PIg serum slightly. Free light chains (ʙelok-Benz Dƶonsa) are found neither in the serum, audio in urine. The disease can occur slowly, with spontannыmi remissiяmi (benign form). The duration of up to 5 years.

Heavy chain disease-α

Ill children and persons under the age of 40 years.

The disease is characterized by lesions of the lamina propria (lamina propria) the mucosa of the small intestine and abdominal lymph nodes as massive infiltration plasmocytes, immature lymphatic reticular cells, immunoʙlastami, macrophages and tissue basophils with symptoms of severe malabsorption (diarrhea, celiac disease, hypocalcemia, kaliopenia). Bone marrow is not affected. M-gradient and no proteinuria.

This disease affects the system IgA-secreting cells. Also described intestinal and pulmonary version of BTC-α, which is very rare and occurs with mediastinal and bronchopulmonary lymph nodes.

There are two phases of BTC-α:

• Benign, in which the cell substrate contains mature lymphocytes and plasma cells;
• phase, proceeds with atypia cellular composition and progressive tumor growth.

Heavy chain disease-μ

Heavy chain disease is rare-μ.

According to clinical and hematological picture resembles chronic lymphocytic leukemia, flowing without increasing peripheral lymph nodes, but with hepatosplenomegaly. Sometimes patients may appear osteolytic lesions and pathological fractures. In the bone marrow, except lymphoid infiltration, vacuolated plasma cells are found.

Electrophoresis of serum can detect hypogammaglobulinemia, and in urine - Bence-Jones protein.

In various embodiments, heavy chain disease serum electrophoresis reveals the same diffuse blur zone γ-, a-глобулинов.

Bence-Jones protein in the urine is detected only when a rare μ-form. Therefore, for the diagnosis of various forms of BTC used serum immunoelectrophoresis (or concentrated urinary) proteins with monospecific antisera against heavy (y-, a-, m-) and light (x-, lambda) chains.

When BTC proteins studied do not react with antisera against the light chains, since BTC-α and BTC-γ in tumor cells the synthesis of light chain offline, and when μ-shaped light chains are synthesized, but does not bind to H-chains of residues.