Monoclonal immunoglobulin deposition disease

A rare disorder characterized by the deposition of monoclonal immunoglobulins in tissues

Monoclonal immunoglobulin deposition disease (MIDD) is a rare disorder characterized by the deposition of monoclonal immunoglobulins in various tissues, leading to organ dysfunction. It is closely related to multiple myeloma and other plasma cell dyscrasias.

Pathophysiology

MIDD is caused by the production of abnormal monoclonal immunoglobulins by a clone of plasma cells. These immunoglobulins, or their fragments, deposit in tissues such as the kidneys, heart, and liver, causing damage and dysfunction. The deposits can be composed of light chains, heavy chains, or both, leading to subtypes such as light chain deposition disease (LCDD), heavy chain deposition disease (HCDD), and light and heavy chain deposition disease (LHCDD).

Clinical Presentation

Patients with MIDD often present with symptoms related to the affected organs. Renal involvement is common, leading to proteinuria, nephrotic syndrome, and progressive renal failure. Cardiac involvement can result in cardiomyopathy and heart failure. Other symptoms may include hepatomegaly, neuropathy, and skin lesions.

Diagnosis

The diagnosis of MIDD involves a combination of clinical evaluation, laboratory tests, and tissue biopsy. Serum protein electrophoresis and immunofixation electrophoresis are used to detect monoclonal proteins in the blood. A kidney biopsy is often performed to confirm the presence of immunoglobulin deposits, which can be visualized using immunofluorescence and electron microscopy.

Treatment

Bortezomib, a proteasome inhibitor used in treatment

The treatment of MIDD focuses on reducing the production of the monoclonal immunoglobulin. This is typically achieved using therapies similar to those used in multiple myeloma, such as chemotherapy, corticosteroids, and proteasome inhibitors like bortezomib. In some cases, autologous stem cell transplantation may be considered.

Prognosis

The prognosis of MIDD varies depending on the extent of organ involvement and the response to treatment. Early diagnosis and effective management of the underlying plasma cell disorder are crucial for improving outcomes. However, the disease can progress to end-stage renal disease or cause significant cardiac complications if not adequately controlled.

Related pages

• Multiple myeloma
• Light chain deposition disease
• Heavy chain deposition disease
• Plasma cell dyscrasia