Correlation between serum magnesium and blood cyclosporine A concentrations in renal transplant recipients

Adverse effects of immunosuppression in pediatric solid organ transplantation

Solid organ transplantation is a life-saving treatment for end-stage organ failure in children. Immunosuppressant medications are used to prevent rejection of the organ transplant. However, these medications are associated with significant adverse effects that impact growth and development, quality of life (QOL), and sometimes long-term survival after transplantation. Adverse effects can differ between the immunosuppressants, but many result from the overall state of immunosuppression. Strategies to manage immunosuppressant adverse effects often involve minimizing exposure to the drugs while balancing the risk for rejection. Early recognition of immunosuppressant adverse effects may help to reduce morbidities associated with solid organ transplantation, improve QOL, and possibly increase overall patient survival.

Allogeneic activation is attenuated in a model of mouse lung perfused with magnesium-deficient blood

Hypomagnesemia, which is frequently observed in patients treated with calcineurin inhibitors to prevent rejection after allogeneic transplantation, has been associated with a faster rate of decline in allograft function. The effect of hypomagnesemia on lung allograft has not been reported yet. In our model of isolated mouse lung, we have evaluated the early effects of allogeneic lung perfusion with blood from magnesium (Mg)-deficient mice for 3 h on lung activation and remodelling, compared to isogeneic perfusion. Hypomagnesemia (0.21+/-0.07 mmol Mg(2+)/l) was observed in blood from Mg-deficient mice, but no inflammatory pattern. The mRNA level of the intercellular adhesion molecule (ICAM)-1, but neither of the vascular cell adhesion molecule (VCAM)-1, nor of the cytokines tumor necrosis factor (TNF)alpha and interleukin (IL)-2, was enhanced (p<0.05). Although caspase-3 mRNA was transiently enhanced, no apoptotic cells were evidenced in lung tissues even after 3 h. Using cDNA array, we found that the genes encoding RANKL, RANK, TNFR2, NFATX, IL-1R2, IL-6R gp130, SOCS3, PDGFRB, P63, CSF3R, CXCL1, CXCL5, CX3CL1, CSF1, which are involved in inflammation and apoptosis regulation, were markedly up-regulated in allogeneic conditions. Our results support a limited allogeneic activation and an early stage of the inflammatory process in lung, at the time of inflammatory cell recruitment without lung tissue remodelling, as a result of hypomagnesemia. These findings suggest that cyclosporine-related hypomagnesemia, observed in most of the transplanted patients, does not constitute an additional risk for lung allograft outcome.

Low serum magnesium is associated with decreased graft survival in patients with chronic cyclosporin nephrotoxicity

BACKGROUND

Hypomagnesaemia is a common side effect of cyclosporin A (CsA) therapy. Animal studies suggest that magnesium (Mg) supplementation inhibits chronic CsA nephropathy.

METHODS

To determine if low Mg levels correlate with true CsA-induced nephrotoxicity in humans, we examined kidney transplant biopsy records at our centre for all transplant biopsies performed between 1990 and 2002. We simultaneously reviewed the medical records to determine whether serum Mg levels were checked at the time of biopsy. Those individuals with histologically proven CsA nephrotoxicity were studied.

RESULTS

Serum total Mg levels were available for 320 patients, 60 of whom were diagnosed with chronic CsA-mediated nephropathy. Patients were divided in two groups, a low Mg [n = 29, 1.8 (1.67-1.9) mg/dl or 0.74 (0.68-0.78) mmol/l] and a normal Mg group [n = 31, 2.2 (2.0-2.4) mg/dl or 0.9 (0.82-0.98) mmol/l, P<0.05] based on the median Mg level in the entire cohort (2 mg/dl or 0.82 mmol/l). Both groups were analysed for disease progression and graft loss using the slope of creatinine clearance (CCR) and multivariate analyses. Although the CCR at the time of biopsy was greater in the low Mg group [44.3 (36.3-64.3) ml/min vs 37.8 (25.2-47.3) ml/min, P<0.05), the decline in graft function was faster in this group (-8.9+/-3.5 vs 1+/-2.7 ml/min/year; P = 0.02) compared with the normal Mg cohort. Using Cox proportional hazards analyses, the adjusted graft survival was significantly reduced in the low Mg group 5 years after biopsy.

CONCLUSIONS

Our study demonstrates that low serum Mg levels were associated with a faster rate of decline in kidney allograft function and increased rates of graft loss in renal transplant recipients with chronic CsA nephropathy. This suggests that hypomagnesaemia could potentiate CsA-mediated nephropathy.

Management of nephrotic syndrome in children

Idiopathic childhood nephrotic syndrome generally has a favorable long-term prognosis. Prompt administration of and improved guidelines for monitoring therapy have decreased morbidity and mortality. The treatment goal is to induce prompt remission while minimizing complications and adverse events. Aggressive therapy induces remission and decreases the frequency of relapse in most patient populations; however, such treatment often results in unnecessary toxicity. We critically assessed the current clinical evidence that supports each pharmacologic therapy. For each drug regimen, the risks and monitoring parameters required to reduce complications and optimize therapy are discussed. Some of the treatments are the common corticosteroid approaches, cytotoxic therapies (chlorambucil, cyclophosphamide), cyclosporine, less frequently used drugs (e.g., levamisole), and experimental therapies. Further studies are needed to identify the most effective and least toxic therapeutic regimens for inducing and maintaining remission in children with nephrotic syndrome.