Biclonal Gammopathies in South Tunisia: Clinical and Biological Characteristics.

Objective: Biclonal gammopathies (BGs) are rare situations characterized by the production of 2 monoclonal proteins. There are no available data on BGs in North Africa. We aimed to estimate the prevalence of BGs in our population and describe their clinical and laboratory features.

Methods: We conducted a 31-year retrospective study including patients with persistent double monoclonal bands based on the results of immunofixation/immunoelectrophoresis.

Results: A total of 35 patients with available clinical data (sex ratio, M/F = 1.53; mean age, 70 ± 10.87 years [range, 45-90 years]) were included. The main associated conditions were multiple myeloma (MM) (40%), BG of undetermined significance (BGUS) (34%), and lymphoproliferative diseases (23%). Only one-third of the patients had 2 monoclonal spikes on serum protein electrophoresis. The most common paraprotein combinations were immunoglobulin (Ig)G-IgG (25%) and IgG-IgA (23%) with different light chains in one-half of the cases. The mean follow-up was 25.6 months (median, 12 months). No BGUS evolved into a malignant disease.

Conclusion: BGs are rare in clinical laboratory routine but must be accurately identified by the pathologist. Our cohort is characterized by a high prevalence of BGUS compared with MM.