Clinical Significance of Microvascular Inflammation in the Absence of Anti-HLA DSA in Kidney Transplantation.

BACKGROUND: Limited information exists about outcomes of HLA donor-specific antibody (DSA) negative (DSA-) microvascular inflammation (MVI). METHODS: We report our experience with 25 DSA- patients with MVI compared to 155 DSA+ patients who met Banff 2013 criteria for antibody-mediated rejection (AMR). We also compared outcomes to 228 DSA+ patients whose biopsies were negative for rejection and served as a negative control. RESULTS: There were no significant differences in the baseline characteristics between the DSA- MVI and DSA+ AMR groups. At the time of diagnosis, both groups had similar graft function. The DSA- group had higher MVI scores but lower C4d scores. At last follow-up, renal function was similar between the groups. There were 12 (48%) graft failures in the DSA- group and 59 (38%) graft failures in the DSA+ group, which was not statistically different. Similar results were found after matching for the MVI scores, C4d, and treatment between 2 groups. We also found similar outcomes between DSA- and DSA+ patients when only including those who would have met Banff 2017 criteria for AMR. In univariate Cox regression analyses, estimated glomerular filtration rate at time of biopsy, glomerulitis, rituximab, diabetes, v score, allograft glomerulopathy, fibrous intimal thickening, tubular atrophy, and interstitial fibrosis scores were associated with graft failure. In multivariate analysis, only estimated glomerular filtration rate was protective. Both groups had significantly worse outcomes than the DSA+-negative controls without AMR. CONCLUSIONS: Our findings suggest that outcomes and response to treatment with HLA DSA- MVI patients are similarly poor to those with DSA+ MVI patients, supporting a critical role for MVI in the diagnosis of AMR.

Subclinical Antibody-mediated Rejection After Kidney Transplantation: Treatment Outcomes.

BACKGROUND: Antibody-mediated rejection (AMR) is a leading cause of morbidity and mortality after kidney transplantation. Early diagnosis and treatment of subclinical AMR based on the donor-specific antibody (DSA) testing may result in better outcomes. METHODS: We tested this hypothesis in 220 kidney transplant recipients who underwent an indication or DSA-based surveillance protocol biopsies between March 1, 2013 and December 31, 2016. Patients were divided into 3 groups: clinical AMR (n = 118), subclinical AMR (n = 25), or no rejection on protocol biopsy (controls; n = 77). RESULTS: Both clinical and subclinical AMR groups underwent similar treatment including plasmapheresis, pulse steroids, IVIG, and rituximab (P = ns). Mean follow-up after AMR was 29.5 ± 16.8 months. There were 2 (3%), 2 (8%), and 54 (46%) death-censored graft failures in the control, subclinical, and clinical AMR groups, respectively (P < 0.001). Graft outcomes were similar in the subclinical rejection and control groups. In adjusted Cox regression analysis, only clinical rejection (hazards ratio [HR], 4.31; 95% confidence interval [CI], 1.01-18.94; P = 0.05) and sum chronicity scores (HR, 1.16; 95% CI, 1.01-1.35; P = 0.03) were associated with increased risk of graft failure, while estimated glomerular filtration rate at time of biopsy (HR, 0.98; 95% CI, 0.96-0.99; P = 0.01) was associated with decreased risk of graft failure. CONCLUSIONS: Our study suggests that early diagnosis and treatment of subclinical AMR using DSA monitoring may improve outcomes after kidney transplantation.

A case report of deferasirox-induced kidney injury and Fanconi syndrome.

Cases of kidney injury associated with the use of deferasirox chelation therapy during the course of treatment for iron overload have been reported infrequently. We present the case of a patient treated with deferasirox who had biopsy-proven tubular injury in the setting of clinical Fanconi syndrome. The patient required hospitalization for metabolic acidosis, electrolyte abnormalities, and associated symptoms. With supportive care and cessation of chelation therapy he improved, but has yet to fully recover. This is the first known case reporting biopsy-proven tubular damage in the setting of deferasirox use.