Posaconazole plasma concentration in pediatric patients receiving antifungal prophylaxis after allogeneic hematopoietic stem cell transplantation.

Posaconazole has been proven to be effective for antifungal prophylaxis in adults after hematopoietic stem cell transplantation (HSCT). Due to low gastrointestinal resorption of posaconazole suspension, bioavailability is impaired. Fatty food improves the uptake of posaconazole, but insufficient data on the pharmacokinetics of posaconazole in pediatric patients are available so far. The single-center analysis investigated 161 posaconazole serum concentrations in 27 pediatric patients after HSCT receiving 12 mg·kg BW(-1)·d(-1) posaconazole suspension depending on age, gender, and intestinal graft-versus-host (iGvHD) disease, and the influence of posaconazole on cyclosporine A plasma concentrations. To improve the uptake of posaconazole, one patient cohort received higher fat nutrition with the drug administration. A comparison of the regular nutrition and higher-fat nutrition groups revealed the following values: 31 (27.4%) versus 8 (16.7%) < 500 ng/ml; 12 (10.6%) versus 7 (14.6%) 500-700 ng/ml; 8 (7.1%) versus 6 (12.5%) 700-1000 ng/ml; 51 (45.1%) versus 21 (43.8%) 1000-2000 ng/ml; and 11 (9.7%) versus 6 (12.5%) > 2000 ng/ml. The mean posaconazole concentrations in patients with regular nutrition was 1123 ± 811 ng/ml and with higher-fat nutrition was 1191 ± 673 ng/ml. Posaconazole levels in patients with iGvHD were significantly lower (P = 0.0003) than in patients without GvHD. The majority of samples showed a sufficient posaconazole concentration above 700 ng/ml. Posaconazole levels were slightly higher in patients with higher-fat nutrition and significantly lower in patients with iGvHD. Cyclosporine A levels were not significantly higher during posaconazole administration.

Antibody-mediated rejection: pathogenesis, prevention, treatment, and outcomes.

Antibody-mediated rejection (AMR) is a major cause of late kidney transplant failure. It is important to have an understanding of human-leukocyte antigen (HLA) typing including well-designed studies to determine anti-MHC-class-I-related chain A (MICA) and antibody rejection pathogenesis. This can allow for more specific diagnosis and treatment which may improve long-term graft function. HLA-specific antibody detection prior to transplantation allows one to help determine the risk for AMR while detection of DSA along with a biopsy confirms it. It is now appreciated that biopsy for AMR does not have to include diffuse C4d, but does require a closer look at peritubular capillary microvasculature. Although plasmapheresis (PP) is effective in removing alloantibodies (DSAs) from the circulation, rebound synthesis of alloantibodies can occur. Splenectomy is used in desensitization protocols for ABO incompatible transplants as well as being found to treat AMR refractory to conventional treatment. Also used are agents targeted for plasma cells, B cells, and the complement cascade which are bortezomib rituximab and eculizumab, respectively.