The impact of Rituximab therapy on the chromosomes of patients with Rheumatoid arthritis.

The open prospective combined cytogenetic and clinical study investigated the impact of biological therapy Rituximab on number and structure of chromosomes in Rheumatoid arthritis patients. The purpose of this study was to investigate safety of Rituximab on chromosomes as well as cytotoxic therapy Methotrexate. A total of 8 seropositive Rheumatoid arthritis patients were analyzed for primary end point of eventual cytotoxic effect of Rituximab. Assessment was done before and 1 month later, actually 2 weeks after the administration of full course of Rituximab in infusion. Patients suffering from active Rheumatoid arthritis were randomly assigned according to established protocol to receive infusion of Rituximab in a full dose of 2.0 grams divided in a two doses of 1.0 gram on days 1 and 15. The lymphocytes from peripheral blood were cultured according to Moorhead method. The results obtained from this investigation showed that normal male and female karyogram was found after the full therapy of Rituximab. The results from this study, that was done on a rather small number of subjects, indicate that Rituximab does not express either clastogenic or aneugenic effects. But, co-finding of this study was that Methotrexate had a side effect on chromosomal aberration in one female RA patient, and after discontinuation of this treatment the normal karyogram was observed.