Donor-Specific Antibodies After Starting Hemodialysis in Nonrenal Solid Organ Transplant Recipients: Role of TH17.

BACKGROUND: Nonrenal transplantation could cause a progressive deterioration in renal function until need dialysis. It is important to know if these patients increased their risk to develop de novo donor-specific anti-HLA antibody (DSA) after starting hemodialysis (HD) and if so, try to find the mechanism. MATERIAL AND METHODS: In this double-phase study, we first analyzed the incidence of development DSA in nonrenal transplant recipients after starting HD by a retrospective study. Secondly, a prospective study was designed to analyze the pharmacokinetics of immunosuppressive drugs and the cytokine profile of these patients. RESULTS: Of 179 pancreas transplant recipients, 16 needed to start HD, and 62.5% of these patients developed de novo DSA after starting HD, with 80% of them class I DSA. In the second phase of the study, the plasma levels of the immunosuppressive drugs as measured by a limited sampling strategy of 3 sample time points (C0, C2, and C4) were stable. The cytokine profile showed that there was an increase in Th1 cytokine (interferon gamma of 0.045 ng/mL) and also in Th17 cytokines (transforming growth factor ß >10 ng/mL). CONCLUSION: Our data suggest that the development of DSA after starting HD in nonrenal transplant recipients could be mediated by Th17 immune response mechanisms.

Short-Term Outcome of Untreated Versus Treated Asymptomatic Bacteriuria in Renal Transplant Patients.

BACKGROUND: Infection of the urinary tract (UTI) is the most common form of bacterial infection in renal transplant patients, but its management is still controversial. We compared symptomatic and asymptomatic bacteriuria, treated or untreated, during two different months (summer or winter). METHODS: This longitudinal, prospective study involved routine urine cultures collected during September 2014 or March 2015. Demographic, clinical, and microbiological characteristics from the patients with positive urine cultures were described. The main outcomes were the need of hospitalization, the bacterial clearance, and the selection of the resistant pathogen. RESULTS: From the 538 urine cultures collected, only 61 were positive urine cultures. Twenty were untreated asymptomatic bacteriuria (AB), 28 were treated AB, and 13 were treated symptomatic bacteriuria. The more prevalent micro-organisms were E coli (27%), K pneumoniae (11%), and E faecalis (7%). There were no differences in the demographic, clinical, and microbiological characteristics depending on the month when the urine cultures were collected. Only 10 patients required hospitalization during follow-up, and all of them belonged to the treated group. Bacterial clearance after the treatment occurred in 20 patients of the 41 treated (48.9%) and spontaneously in 14 of the 20 patients untreated (70%). Of the treated patients, 47.6% developed a new resistance to another antibiotic. CONCLUSIONS: Only 7.6% of the routine urine cultures on renal transplant were positive. Untreated AB did not require hospitalization, and 70% had spontaneous bacterial clearance.