Variations in the Frequency and Type of Infections in Heart Transplantation According to the Immunosuppression Regimen

Association of genetic polymorphisms and risk of late post-transplantation infection in pediatric heart recipients

BACKGROUND

Late infections are common causes of morbidity and mortality after pediatric heart transplantation. In this multicenter study from 6 centers, we investigated the association between genetic polymorphisms (GPs) in immune response genes and late post-transplantation infections in 524 patients.

METHODS

Late infection was defined as a clinical infectious process occurring >60 days after transplantation and requiring hospitalization, intravenous antimicrobial therapy, or a life-threatening infection requiring oral therapy. All patients provided a blood sample for GP analyses of 18 GPs in cytokine, growth factor, and effector molecule genes by single specific primer-polymerase chain reaction and/or sequencing. Significant associations in univariable analyses were tested in multivariable Cox regression models.

RESULTS

Late infection was common, with 48.7% of patients experiencing ≥ 1 late infection, 25.2% had ≥ 1 late bacterial infection, and 30.5% had ≥ 1 late viral infection. Older age at transplantation was a protective factor for late infection, both bacterial and viral (hazard ratio [HR] 0.89-0.92 per 1-year age increase, p < 0.001). Adjusting for age, race, and transplant etiology, late bacterial infection was associated with HMOX1 A+326G AG and GG genotypes (HR, 2.41, 95% confidence interval [CI] 1.35-4.30; p = 0.003) and GZMB A-295G AA genotype (HR, 1.47; 95% CI; 1.03-2.1; p = 0.036). Late viral infection was associated with FAS A-670G GG genotype (HR, 1.42; 95% CI, 1.00-2.00; p = 0.050) in the adjusted model and with CTLA4 A+49G AA and AG genotypes (HR, 1.49; 95% CI, 1.02-2.19; p = 0.041) in univariable analysis.

CONCLUSION

We found an association between late bacterial infection and GP of HMOX1, which may control macrophage activation. A weaker association was also found between late viral infection and GP of CTLA4, a regulator of T-cell activation. This represents progress toward understanding the clinical and genetic risk factors of outcomes after transplantation.

Randomized prospective study of the evolution of renal function depending on the anticalcineurin used

BACKGROUND

Renal failure is one of the primary medium- to long-term morbidities in heart transplant (HT) recipients. To a great extent, this renal deterioration is associated with calcineurin inhibitors, primarily cyclosporine A (CsA). It has been suggested that tacrolimus provides better renal function in these patients. We assessed the medium-term evolution of renal function depending on the calcineurin inhibitor used after HT.

PATIENTS AND METHOD

We assessed 40 consecutive HT recipients over one year. Patients were randomized to receive CsA (n = 20) or tacrolimus (n = 20) in combination with mycophenolate mofetil (1 g/12 h) and deflazacort in decreasing dosages. We analyzed demographic variables before HT, creatinine values before and six months after HT and incidence of acute rejection.

RESULTS

No demographic, clinical, or analytical differences were observed were between the two groups before HT. Repeated measures analysis of variance of creatinine values showed no significant differences between the two groups (P = .98). Furthermore, no differences were observed in either the incidence of rejection (P = .02) or rejection-free survival (P = .14).

CONCLUSION

There seems to be no difference in efficacy profile and renal tolerability between CsA and tacrolimus therapy during the first months after HT.

Tacrolimus in Heart Transplant Recipients

The development of cyclosporine was pivotal in allowing cardiac transplantation to become an accepted treatment for patients with end-stage heart disease. More recently, tacrolimus has become available as a useful alternative to cyclosporine, and has been successfully combined with either azathioprine or the newer anti-proliferative agents, mycophenolate mofetil or sirolimus. Numerous randomized clinical trials have demonstrated that tacrolimus is comparable to cyclosporine in terms of overall patient survival and at least equally effective in preventing acute rejection. In addition, tacrolimus has been particularly effective as a rescue treatment in cases where recurrent rejection has occurred with cyclosporine. The adverse effects of tacrolimus differ from those of cyclosporine, and the drug particularly shows an improved profile with respect to hypertension, dyslipidemia, and long-term renal function. These data have recently led to the regulatory approval of tacrolimus for primary immunosuppression in patients undergoing cardiac transplantation in the US.