Polymorphic variants of SCN1A and EPHX1 influence plasma carbamazepine concentration, metabolism and pharmacoresistance in a population of Kosovar Albanian epileptic patients

Aim The present study aimed to evaluate the effects of gene variants in key genes influencing pharmacokinetic and pharmacodynamic of carbamazepine (CBZ) on the response in patients with epilepsy. Materials & Methods Five SNPs in two candidate genes influencing CBZ transport and metabolism, namely ABCB1 or EPHX1, and CBZ response SCN1A (sodium channel) were genotyped in 145 epileptic patients treated with CBZ as monotherapy and 100 age and sex matched healthy controls. Plasma concentrations of CBZ, carbamazepine-10,11-epoxide (CBZE) and carbamazepine-10,11-trans dihydrodiol (CBZD) were determined by HPLC-UV-DAD and adjusted for CBZ dosage/kg of body weight. Results The presence of the SCN1A IVS5-91G>A variant allele is associated with increased epilepsy susceptibility. Furthermore, carriers of the SCN1A IVS5-91G>A variant or of EPHX1 c.337T>C variant presented significantly lower levels of plasma CBZ compared to carriers of the common alleles (0.71±0.28 vs 1.11±0.69 μg/mL per mg/Kg for SCN1A IVS5-91 AA vs GG and 0.76±0.16 vs 0.94±0.49 μg/mL per mg/Kg for EPHX1 c.337 CC vs TT; PG showed a reduced microsomal epoxide hydrolase activity as reflected by a significantly decreased ratio of CBZD to CBZ (0.13±0.08 to 0.26±0.17, pT SNP and SCN1A 3148A>G variants were not associated with significant changes in CBZ pharmacokinetic. Patients resistant to CBZ treatment showed increased dosage of CBZ (657±285 vs 489±231 mg/day; P<0.001) but also increased plasma levels of CBZ (9.84±4.37 vs 7.41±3.43 μg/mL; P<0.001) compared to patients responsive to CBZ treatment. CBZ resistance was not related to any of the SNPs investigated. Conclusions The SCN1A IVS5-91G>A SNP is associated with susceptibility to epilepsy. SNPs in EPHX1 gene are influencing CBZ metabolism and disposition. CBZ plasma levels are not an indicator of resistance to the therapy

[Treatment With Lo-tact-1, a Monoclonal-antibody To the Interleukin-2 Receptor, in Renal-transplantation]

From May to August 1989 15 cadaver-donor renal transplant recipients were treated for 14 days with LO-Tact-1 (10 mg i.v. per day) in combination with cyclosporin (8 mg/kg/day from day -1), low-dose steroids (1/2 mg/kg/day from day 1, then reduced to 0.25 mg/kg at day 26 and 10 mg/day at day 45), and azathioprine (1 mg/kg/day) started at day 45. LO-Tact-1 is a rat monoclonal antibody which is directed to the interleukin-2 receptor. The control group consisted of 20 patients receiving cyclosporin, high-dose steroids (2 mg/day at day 1) and a 14-day course of polyclonal horse antilymphocyte globulins (ALG). Seven patients experienced 9 rejections during the first 3 months post-transplant between day 10 and day 67 (mean 0.6 per patient), comparable to the incidence of rejections in the control group: 8 rejections in 7 patients (mean 0.4 per patient). All rejections were reversed by steroid boluses and ATG. To date, all study patients have functioning grafts, and at 1-year post-transplant, the mean blood creatinine level is 161.2-mu-mol/l. In the control group, one patient died of CMV infection, and 2 other grafts failed due to rejection. No adverse effect of antibody administration was observed, and hematological changes remained of minor importance. Viral infections were not observed, except one case of herpes simplex. Comparatively, clinical CMV infections occurred in 3 patients receiving ALG (15 percent). Our data suggest that a combination anti-IL-2 monoclonal antibody, cyclosporin and low-dose steroids can safely be administered to allograft recipients, avoid severe viral infections, and, in our early experience, is as potent as the powerful combination ALG, cyclosporin and high-doses steroids in preventing allograft rejection