Gamma delta TCR-bearing intraepithelial lymphocytes regulate class II major histocompatibility complex molecule expression on the mouse small intestinal epithelium

OBJECTIVE: To examine the hypothesis that addition of therapeutic plasma exchange (TPEX) to an immunosuppressive drug regimen increases that regimen's efficacy to halt the progression of chronic progressive multiple sclerosis (CPMS). METHODS: The literature was searched for prospective controlled clinical trials evaluating the efficacy of TPEX in CPMS. Six studies were eligible for meta-analysis. Their results were combined, using Cochran's and Peto's methods. Three outcome measures were studied: 1) the change in Kurtzke's disability status scale (DSS) scores, 2) the relative odds of neurologic decline by 1 or more DSS grades, and 3) the relative odds of neurologic improvement by 1 or more DSS grades, in the treatment versus the comparison group of patients. Reported results of neurologic evaluations at 6, 12, 24, and 36 months of follow-up were analyzed separately. RESULTS: TPEX significantly (P < .05) reduced the proportion of patients who experienced neurologic decline (by 1 or more DSS grades) at 12 months of follow-up (relative odds of decline = 0.441, 95% confidence interval = 0.210-0.929). CONCLUSIONS: There is a need for further clinical research into the possibility of a beneficial effect of TPEX in patients with CPMS likely to experience neurologic decline over the ensuring 12 months. Targeting treatment to a particular subgroup of CPMS patients may be necessary for TPEX to prove effective.