Effect of colchicine on immunoregulatory abnormalities in familial Mediterranean fever

The effect of colchicine on immunoregulatory T lymphocytes in children with familial Mediterranean fever (FMF) was studied. Concanavalin A (Con-A)-induced suppressor cell function was significantly (P <0.0001) decreased in 5 untreated FMF patients (15±3%, mean ± s.e.) as compared to 6 age matched paediatric controls (46±3%) and 8 healthy adults (49±4%). When the 5 untreated FMF patients' mononuclear cells were pre-incubated in vitro with Con A plus 10^-5 M colchicine, their suppressor cell function was significantly increased (52±10%, P <0.01). Similarly, oral colchicine treatment (0.5 mg twice daily) significantly (P=0.02) increased the 5 FMF patients' Con A-induced suppressor cell function to levels (34±6%) that were not significantly (P >0.05) different from the paediatric controls or the healthy adults. The percentage of OKT8⁺ cells (but not OKT3⁺ or OKT4⁺ cells) was significantly (P <0.0001) decreased in 10 untreated FMF patients (16.0±0.9) as compared to 10 paediatric controls (27.6±2) or 10 healthy adults (25.7±0.6). The 10 untreated FMF patients had a significant (P <0.002) increase in the OKT4/OKT8 ratio (2.41±0.13) as compared to 10 FMF patients treated with 0.5 mg twice daily of colchicine (1.81±0.08), 10 pediatric controls (1.47±0.2), or 10 healthy adults (1.78±0.11). Colchicine appears to have corrected the FMF patients' elevated OKT4/OKT8 ratio by both decreasing the percentage of OKT4⁺ cells and increasing (but only partially correcting) the percentage of OKT8⁺ cells. Thus, FMF patients have a suppressor cell deficiency in which colchicine treatment corrects their deficiency of Con A-induced suppressor cell function and their elevated OKT4/OKT8 ratio. This raises the possibility that colchicine might be potentially useful as an immunomodulating drug in treating patients with autoimmune or allergic diseases associated with a suppressor cell deficiency.