The occurrence of Al amyloidosis (light-chain amyloidosis) in patients with multiple myeloma in Lower Silesia Region, Poland.

BACKGROUND The incidence of amyloidosis is difficult to determine because the disease is often undiagnosed or diagnosed incorrectly. In Polish studies, there are no statistics and analyses of the factors that may influence the development of amyloidosis in patients with multiple myeloma. OBJECTIVES The goal of this study was to estimate the incidence of AL amyloidosis in MM patients in Lower Silesia region. MATERIAL AND METHODS 70 patients treated at the Department of Hematology, Provincial Hospital in Legnica and the Department of Hematology, Blood Neoplasm and Bone Marrow Transplantation, Medical University in Wroclaw were enrolled in the survey. 37 patients were newly diagnosed, 33 had been treated for 2-34 months. The basis for the diagnosis of amyloidosis was the presence of green colored amyloid deposits in the polarized light microscope in the adipose tissue (received from abdominal fold and stained with Congo red). RESULTS Amyloidosis was diagnosed in 18 (25.7%) patients with MM, 9/9 F /M, aged 47-83 years. 6 (33%) pts with amyloidosis had newly diagnosed MM, in 12 (67%) progression of the disease was diagnosed. Amyloidosis occurred significantly more often (p = 0.048) in already treated patients. The odds ratio (OR) was 2.95. Amyloidosis occurred most frequently in patients with IgG myeloma (67%), (OR = 1.98), was more often found in patients with kappa light chain versus lambda, respectively 67% and 33%. The probability of amyloidosis in patients with clinical stage III was 1.5 times higher (p = 0.05) than in other stages (OR = 1.5), in persons with renal dysfunction was twice as high (OR = 2.4) compared to the renal competence group (p = 0.05). CONCLUSIONS AL amyloidosis in the course of MM occurs in Lower Silesia region with a comparable rate to other regions of the world. It is significantly more often diagnosed in patients with relapsed or refractory disease, in persons with clinical stage III and with renal failure.