Monoclonal gammopathy and other serum protein electrophoresis patterns in patients with HIV infection in South Africa

Abstract

Background Monoclonal gammopathy has been noted with increased frequency in patients with HIV infection compared with the general population. The prevalence in patients on antiretroviral therapy (ART) has not been widely investigated. The present study aims to describe the prevalence and characteristics of monoclonal proteins in a population of HIV-infected patients in the Western Cape region of South Africa. Methods Clinical information and blood and urine samples were collected from patients with proven HIV infection attending two clinics in the Western Cape. Serum protein electrophoresis was performed on all patients using agarose gel. Those with visible mono- or oligoclonal bands or increased gamma fractions were subjected to immunofixation electrophoresis. Results Three hundred and sixty-eight patients were included in the study with a mean age of 37.7 y. Of these patients, 326 were on ART for a mean duration of 19.6 months. Monoclonal bands were found in 12 patients (3.2%) and oligoclonal bands in 14 (3.8%). These bands were associated with a shorter duration of ART, increased total protein, acute on chronic phase pattern on electrophoresis and an increased gamma fraction, but not associated with CD4 count and viral load. The majority were of low concentration and of the IgG isotype. Conclusion Our study confirms that the prevalence of monoclonal and oligoclonal bands is higher in this HIV-positive cohort on ART compared with that of the general population. However, the prevalence is lower than previously reported in other studies.