Epidemiological and immunochemical parameters of monoclonal plasma cell dyscrasias of 2121 cases in Algeria.

BACKGROUND: Plasma cell dyscrasias (PCD) are a heterogeneous group of diseases characterized by the expansion of monoclonal bone marrow plasma cells that produce a monoclonal immunoglobulin (M-component). PURPOSE: This is a retrospective study that describes the epidemiological, immunochemical features and etiology of monoclonal gammopathies diagnosed between 1998 and 2016 in the Teaching Hospital Beni-Messous of Algiers. PATIENTS AND METHODS: 2121 cases of monoclonal gammopathies (MG) were collected during this period. Serum/urine protein electrophoresis, serum/urine immunofixation and serum free light chain measurements were used to demonstrate M protein. RESULTS: The middle age of the patients at the time of the diagnosis were 62.96 ± 13.19 years with extremes ranging from 07 to 99 years. The study included 1013 (47, 76 %) men and 1108 (52, 23 %) women with a sex ratio 0,91. Isotypes repartition was: IgG (60.91 %), IgA (17.91 %), light chain (10.46 %), IgM (6.6 %), IgD (1.03 %) and IgE (0.09 %) of cases. The most frequent diagnosis was: Multiple Myeloma (55.20 %), followed by monoclonal gammopathy of undetermined significance (34.13 %). CONCLUSION: In our study, two particularities were noted. There is no male predominance in Algerian PCD patients. Moreover, we observed a higher frequency of light chain multiple myeloma and lower frequency of IgM isotype compared to western studies.

IgD multiple myeloma: Clinical, biological features and prognostic value of the serum free light chain assay.

IgD multiple myeloma (MM) is a rare subtype of myeloma, it affects less than 2% of patients with MM. To evaluate the clinical and prognostic attributes of serum free light chains (sFLCs) analysis, we examined 17 cases of IgD MM. From 1998 to 2012, we obtained 1250 monoclonal gammapathies including 590 multiple myeloma and 17 patients had IgD MM. With preponderance of men patients with a mean age at diagnosis of: 59±12years. Patients with IgD MM have a short survival (Median survival=9months). The presenting features included: bone pain (75%), lymphadenopathy (16%), hepatomegaly (25%), splenomegaly (8%), associated AL amyloidosis (6%), renal impairment function (82%), infections (47%), hypercalcemia (37%) and anemia (93%). Serum electrophoresis showed a subtle M-spike (Mean=13.22±10g/L) in all patients associated to a hypogammaglobulinemia. There was an over-representation of Lambda light chain (65%); high serum ß2-microglobulin in 91% and Bence Jones proteinuria was identified in 71%. The median rate of sFLCs κ was 19.05mg/L and 296.75mg/L for sFLCs λ. sFLCR was abnormal in 93% of patients and it showed concordance between baseline sFLCR and the survival (P=0.034). The contribution of FLC assay is crucial for the prognosis of patients with IgD MM.