Baseline characteristics and evolution of Brazilian patients with atypical hemolytic uremic syndrome: first report of the Brazilian aHUS Registry.

Background: Atypical hemolytic uremic syndrome (aHUS) is an ultra-rare disease. Therefore, studies involving large samples are scarce, making registries powerful tools to evaluate cases. We present herein the first analysis of the Brazilian aHUS Registry (BRaHUS). Methods: Analysis of clinical, laboratory, genetic and treatment data from patients inserted in the BRaHUS, from 2017 to 2020, as an initiative of the Rare Diseases Committee of the Brazilian Society of Nephrology. Results: The cohort consisted of 75 patients (40 adults and 35 pediatric). There was a predominance of women (56%), median age at diagnosis of 20.7 years and a positive family history in 8% of cases. Renal involvement was observed in all cases and 37% had low C3 levels. In the <2 years of age group, males were predominant. Children presented lower levels of hemoglobin (P = .01) and platelets (P = .003), and higher levels of lactate dehydrogenase (LDH) (P = .004) than adults. Genetic analysis performed in 44% of patients revealed pathogenic variants in 66.6% of them, mainly in CFH and the CFHR1-3 deletion. Plasmapheresis was performed more often in adults (P = .005) and 97.3% of patients were treated with eculizumab and its earlier administration was associated with dialysis-free after 3 months (P = .08). Conclusions: The cohort of BRaHUS was predominantly composed of female young adults, with renal involvement in all cases. Pediatric patients had lower hemoglobin and platelet levels and higher LDH levels than adults, and the most common genetic variants were identified in CFH and the CFHR1-3 deletion with no preference of age, a peculiar pattern of Brazilian patients.

Thrombotic microangiopathy associated with arboviral infection: Report of 3 cases.

Dengue fever and chikungunya are viral diseases that have spread rapidly throughout the world in recent decades. The occurrence of complications is well known, including prerenal acute kidney injury (AKI), which is usually thought to be caused by dehydration and fluid loss. Thrombotic microangiopathy (TMA) is an uncommon aggravation of dengue fever and chikungunya, with only a few cases described in the medical literature. The aim of this study is to present 3 cases of TMA associated with arboviral infection. Three patients with clinical history, laboratory test, and kidney biopsy results compatible with TMA were selected for the study, 2 of whom had a serological diagnosis of dengue fever and 1 of chikungunya. The 3 patients were followed up at the Federal University of Maranhão Hospital's Nephrology Service in 2018. A targeted gene panel sequencing (TGPS) plus multiple to atypical hemolytic uremic syndrome (aHUS) multiplex ligation-dependent probe amplification (MLPA) was performed in 2 of the patients and revealed in the patient 1 a heterozygous pathogenic variant in the gene THBD, as well as heterozygous deletions in CFH, CFHR1, and CFHR3. In the patient 2, there were heterozygous pathogenic variant in the genes CFI and CFB, in addition to heterozygous deletions in the genes CFHR1 and CFHR3. Both received treatment with eculizumab and undergone recovery of renal function. The third patient had TMA not classified as either aHUS or thrombotic thrombocytopenic purpura (TTP); he abandoned the treatment and returned to the service after 2 years for a dialysis emergency. Patients with arboviral infectious disease and changes that suggest TMA should have appropriate support to establish early diagnosis and useful treatment.

[Star fruit as a cause of acute kidney injury]. / Carambola como causa de lesão renal aguda.

The star fruit belongs to the family Oxalidacea, species Averrhoa carambola. It is rich in minerals, vitamin A, C, B complex vitamins and oxalic acid. Recent studies show that the toxicity of the fruit differs between the patients and may be explained by single biological responses, age, and the intake quantity of the neurotoxin in each fruit in addition to glomerular filtration rate given by each patient. Additionally, the nephrotoxicity caused by the fruit is dose-dependent and may lead to the deposition of crystals of calcium oxalate intratubular, as well as by direct injury to the renal tubular epithelium, leading to apoptosis of the same. We report the case of a patient who after ingestion of the juice and fresh fruit, developed acute renal failure requiring dialysis, evolving with favourable outcome and recovery of renal function.

Carambola como causa de lesão renal aguda / Star fruit as a cause of acute kidney injury

A carambola pertence à família das Oxalidáceas, espécie Averrhoa carambola. É rica em sais minerais, vitaminas A, C, complexo B e ácido oxálico. Estudos recentes demonstram que a toxicidade da fruta difere entre os indivíduos e pode ser explicada pelas respostas biológicas individuais como idade, quantidade da ingestão, neurotoxinas em cada tipo de fruta. Adicionalmente, a nefrotoxicidade causada pela fruta é dose dependente, podendo levar ao desenvolvimento de lesão renal aguda pela deposição de cristais de oxalato de cálcio intratubular, assim como por lesão direta das células epiteliais tubulares, levando à apoptose das mesmas. Relatamos o caso de uma paciente que, após a ingestão do suco da fruta e fruta in natura, desenvolveu lesão renal aguda, necessitando de terapia dialítica, evoluindo com desfecho favorável e recuperação da função renal.

The star fruit belongs to the family Oxalidacea, species Averrhoa carambola. It is rich in minerals, vitamin A, C, B complex vitamins and oxalic acid. Recent studies show that the toxicity of the fruit differs between the patients and may be explained by single biological responses, age, and the intake quantity of the neurotoxin in each fruit in addition to glomerular filtration rate given by each patient. Additionally, the nephrotoxicity caused by the fruit is dose-dependent and may lead to the deposition of crystals of calcium oxalate intratubular, as well as by direct injury to the renal tubular epithelium, leading to apoptosis of the same. We report the case of a patient who after ingestion of the juice and fresh fruit, developed acute renal failure requiring dialysis, evolving with favourable outcome and recovery of renal function.