A decrease in the incidence of Shiga toxin-related hemolytic uremic syndrome as a cause of kidney transplantation at an argentine referral center.

BACKGROUND: In Argentina, Hemolytic uremic syndrome caused by Shiga toxin-producing Escherichia coli (STEC HUS), is the main cause of acute kidney injury and the second cause of end-stage renal disease (ESRD) in children. In recent decades, strategies have been implemented to reduce progression to ESRD, but it is not known whether the cumulative incidence of HUS requiring kidney transplantation (KTx) has decreased. We aimed to determine whether the cumulative incidence of STEC HUS in children undergoing KTx decreased and compared outcomes of HUS-related KTx vs. those related to other etiologies. METHODS: All patients who underwent KTx at our institution were evaluated. The cohort was divided into quintiles (Q), and we compared the cumulative incidence of HUS-related KTx vs KTx due to other etiologies. RESULTS: A total of 1000 consecutive KTx were included. The cumulative incidence of HUS-related KTx was 11%. HUS was the second cause of KTx in Q1: 17% (1988-1995); Q2: 13.5% (1996-2003); Q3: 11.5% (2004-2009) and third cause in Q4: 10% (2010-2015) and Q5: 3% (2016-2021). The cumulative incidence of HUS-related KTx decreased in Q4 and Q5 compared to Q1, Q2, and Q3 and the decline was even steeper when comparing Q4 to Q5 (p:0.019). There was no difference in graft survival in patients with HUS vs. congenital anomalies of kidney and urinary tract (CAKUT) but better than in those with focal segmental glomerulosclerosis (FSGS). CONCLUSIONS: In this cohort, the cumulative incidence of HUS-related KTx decreased, which may have been due to the implementation of nephroprotective strategies.

Kidney transplantation in children with CAKUT and non-CAKUT causes of chronic kidney disease: Do they have the same outcomes?

Almost half the children who undergo kidney transplantation (KTx) have congenital abnormalities of the kidney and urinary tract (CAKUT). We compared patient, graft survival, and kidney function at last follow-up between CAKUT and non-CAKUT patients after KTx. We divided the analysis into two eras: 1988-2000 and 2001-2019. Of 923 patients, 52% had CAKUT and 48% non-CAKUT chronic kidney disease (CKD). Of the latter, 341 (77%) had glomerular disease, most frequently typical HUS (32%) and primary FSGS (27%); 102 had non-glomerular disease. CAKUT patients were more often boys, younger at KTx, transplanted more frequently preemptively, but with longer time on chronic dialysis. They had less delayed graft function (DGF) and better eGFR, but higher incidence of urinary tract infection (1 year post-KTx). In both eras, 1-, 5-, and 10-year patient survival was similar in the groups, but graft survival was better in CAKUT recipients vs those with primary glomerular and primary recurrent glomerular disease: Era 1, 92.3%, 80.7%, and 63.6% vs 86.9%, 70.6%, and 49.5% (P = .02), and 76.7%, 56.6%, and 34% (P = .0003); Era 2, 96.2%, 88%, and 73.5% vs 90.3%, 76.1%, and 61% (P = .0075) and 75.4%, 54%, and 25.2% (P < .0001), respectively. Main predictors of graft loss were DGF, late acute rejection (AR), and age at KTx in CAKUT group and disease relapse, DGF, early AR, and number of HLA mismatches in recipients with glomerular disease. Graft survival was better in CAKUT patients. DGF was the main predictor of graft loss in all groups. Disease recurrence and early AR predicted graft failure in patients with glomerular disease.