[Multiple myeloma with D immunoglobulin]. / Myélome multiple à immunoglobuline D.

ABSTRACT

The immunoglobulin D multiple myeloma is a rare form of multiple myeloma and affects a young population. It is characterized by its clinical severity and poor prognosis. We report four cases of multiple myeloma immunoglobulin D diagnosed and supported in the university hospital Center of Sale and Rabat-Morocco. We propose to study the epidemiological, clinical and biological characteristics of this rare type of monoclonal gammopathy. Through the observations reported, the clinical aspect of myeloma is characterized by the high frequency of extra-bone manifestations including impaired kidney function. The immunoglobulin D multiple myeloma is mainly type λ, the IgD κ is rare, the predominance of λ light chains could be explained by rearrangements at the immunoglobulin genes. Bence-Jones proteinuria is almost constant in the multiple myeloma immunoglobulin D, it is mainly type λ, reflecting excess production of light chains by plasma cells. The marrow is invaded by plasma cells in very different proportions of up to 95%. It's a clinical entity, difficult to diagnose, particularly when low homogeneous band on electrophoresis goes unnoticed for an eye inexperienced or when immune serum anti-IgD was not used during the immunotyping.