Background Antibody-mediated rejection (AMR) was described in kidney transplant patients after viral infections, such as the cytomegalovirus. Very few cases were recently reported after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, probably in the context of lowering of immunosuppressive therapy. To date, no direct immunological link was proved to explain a connection between the coronavirus disease 19 (COVID-19) infection and antibody-mediated rejection (AMR) if it exists. Case presentation Here we try to find this association by presenting the case of a low immunological risk patient who presented, six years post-transplant, with c4d negative antibody mediated rejection due to an anti-HLA-C17 de novo donor specific antibody (DSA) after contracting the coronavirus disease 19. The HLA-Cw17 activated the antibody-dependent cell-mediated cytotoxicity via the KIR2DS1 positive NK cells. Discussion and conclusions This case report may prove a direct role for COVID-19 infection in AMRs in the kidney transplant recipients, leading us to closely monitor kidney transplant recipients, especially if they have “at-risk” donor antigens.

Coronavirus disease 2019 (COVID-19) is a rapidly spreading infective disease caused by the severe acute respiratory syndrome coronavirus 2 virus (SARS-CoV-2). The management of this disease remains a challenge particularly in certain subgroups of patients such in hemodialysis patients who have higher exposure rates due to the nature of their in-hospital care, and higher mortality due to their burden of comorbidities. We report a case of a 52-year-old patient with Von Hippel Lindau syndrome and end-stage renal disease on hemodialysis who contracted COVID-19 infection. Despite the patient's rapidly deteriorating clinical status he was successfully treated with Tocilizumab, after which he showed rapid improvement in his clinical, biological and radiological parameters. Although few studies were available regarding the use of Tocilizumab in the dialysis population, its use proved to be effective and well tolerated in our patient.

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Background: Coronavirus disease 2019 (COVID-19) is a rapidly spreading infective disease caused by the severe acute respiratory syndrome coronavirus 2 virus (SARS-CoV-2). The management of this disease remains a challenge particularly in certain subgroups of patients such in hemodialysis patients who have higher exposure rates due to the nature of their in-hospital care, and higher mortality due to their burden of comorbidities. Moreover, molecules used in the general population to treat COVID-19 lack data regarding their pharmacodynamics in the hemodialysis population.Case presentation: We report a case of a 52-year-old patient with Von Hippel Lindau syndrome and end stage renal disease on hemodialysis who contracted COVID-19 infection. Due to the patient’s rapidly deteriorating clinical status he was successfully treated with Tocilizumab, despite the lack of data concerning the use of this molecule in this population. The patient was later discharged after a long hospital stay and progressive clinical, biological and radiological improvement.Conclusion: This sub group of patients should be carefully approached due to the unique nature of their comorbidities, and to their immune’s system response to the virus itself and to novel therapies. Although few studies were available regarding the use of Tocilizumab in the dialysis population, its use proved to be effective and well tolerated in our patient.

Adenine phosphoribosyltransferase (APRT) deficiency is a rare disorder caused by an autosomal recessive genetic disease leading to the deposition of 2,8-dihydroxyadenine (2,8-DHA) in the kidney. The disease remains under-recognized, oftentimes diagnosed in late stages of renal insufficiency or a failed kidney allograft with biopsy-proven disease recurrence. Here, we present the case of a 59-year-old middle eastern male patient diagnosed with 2,8-DHA nephropathy after a very unusual presentation, and we show how the initiation of an appropriate therapy slowed down his evolution toward kidney replacement therapies. His disease was found to be secondary to a specific APRT gene variant c.188G>A p (Gly63Asp) also described in 4 other patients, all from middle eastern origins.

Background and Aims High flux hemodialysis has largely replaced low flux hemodialysis in developed countries. Clinical trials, in particular the Hemo and the MPO studies, conducted many years ago, showed that the survival benefit was mainly for patients on long term hemodialysis for the first one and for high risk patients with low albumin level (less than 40g/dl) for the latter. Moreover, the effect on hematopoiesis or mineral balance is not unequivocally established in the literature. In Lebanon, following the recommendations of the ministry of health, we switched patients undergoing hemodialysis at our center from low to high flux starting April 2019. We aimed in this study to assess the effect of this switch on hemoglobin level, dose of ESA used, mineral metabolism parameters and nutritional parameters. Method This is an observational pre-post study where each patient is his own control. Subjects included are adults on chronic hemodialysis for more than 6 months at Hotel Dieu de France University Hospital. Patients who needed transfusion for bleeding, admission to the hospital or parathyroidectomy during the study period were excluded from the study. Demographic parameters, medical history and laboratory values were extracted from the patients’ files. Paired t- test was used to compare values obtained in the 6 months on low flux compared to the 6 months on high flux hemodialysis. Results Seventy four patients received sequentially both techniques (45 males and 29 females). Mean age was 66 years, mean dialysis vintage 65 months, diabetic and vascular diseases were the most frequent causes of ESRD found in 27 and 15% of the cases. Hemoglobin level significantly increased from 11 +/- 0.82 to 11.26 +/- 0.67 mg/dl (p=0.04) with a non-significant trend towards a lower ESA dose: 11620 UI/week (+/-2275 UI) in the first period versus 10860 UI/week (+/-2609 UI) during the second period (p=0.15). Ferritin levels were higher in the second part of the study (416 v/s 476 ng/ml) which may have contributed to the increase in hemoglobin. Phosphorus level decreased from 1.55 to 1.48 mmol/l (p=0.008) at the same doses of binders and practically stable levels of calcium and PTH. Most interestingly, albumin level increased from 38 to 40.3 g/dl (p<0.001). Finally urea reduction ratio increased from 73.1% to 74.5% with a p value of 0.001. Conclusion Assuring quality ultrapure water is still a challenge in many developing countries. Lack of firm evidence on beneficial effect in terms of mortality may delay sanitary authorities from imposing high flux hemodialysis. In our study, switching from low to high flux hemodialysis showed positive impact on phosphorus levels but most interestingly increased albumin levels a major predictor of mortality in hemodialysis patients.

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Background and Aims 2, 8 dihydroxyadenine (DHA) deposition is a less known etiology of crystal-induced nephropathy, caused by a deficiency in a purine salvage enzyme, the adenine phosphoribosyl transferase (APRT). DHA is an insoluble molecule in urine leading to crystal formation, tubular obstruction or stone formation. The disease manifests as a history of urolithiasis, chronic kidney disease and even loss of renal allograft when the disease is undiagnosed in native kidneys. The cornerstone of treatment is the inhibition of xanthine dehydrogenase reducing thus the formation of 2,8-DHA and its renal excretion. Method A 59-year-old obese Lebanese male patient, born to a consanguineously married couple, was admitted to another hospital with desaturation, a history of progressive shortness of breath and a creatinine level of 2,8 mg/dl. He had no hypertension nor diabetes. His family history was positive for a sister with ESRD of unknown etiology. He was discharged on oxygen and continuous airway positive pressure therapy for severe obstructive sleep apnea. His renal function deteriorated leading to a creatinine level of 9.8 mg/dl three months later. There were no signs of systemic disease, no gross hematuria, no fluid overload. His blood pressure was normal. Laboratory work up showed anemia, low grade proteinuria, intermittent microscopic hematuria and negative serological and immunological workup. Kidney ultrasound showed normal size kidneys with no evidence of collecting system dilatation or urolithiasis. Due to this atypical presentation, the patient was admitted for a renal biopsy with a creatinine level of 11 mg/dl upon admission. Results The renal biopsy showed tubulo-interstitial nephritis associated with numerous brown-green crystals by Haematoxylin and eosin of various shapes birefringent under polarized light with the characteristic “maltese cross”. Crystals were found within tubular lumens and cytoplasm, interstitium, and macrophages. These findings were characteristic of 2,8 DHA crystals deposition in the kidney. The patient was started on 120 mg of Febuxostat with a low purine and high fluid diet. A genetic testing showed a pathogenic homozygous variant in the APRT gene which causes an amino acid change from Glycine to Aspartate at position 63. Two weeks later the patient was admitted to the ICU with pneumonia, respiratory failure, a creatinine of 9 mg/dl and severe metabolic encephalopathy. He received 4 sessions of hemodialysis followed by an improvement in his kidney function with a creatinine level down to 3.2 mg/dl a month after his discharge and he remains off dialysis until now. Conclusion Around 400 cases are currently recognized worldwide, emphasizing the under recognition of this autosomal recessive disease. Considering that the homozygoty causing a complete APRT deficiency should range between 1/50 000 and 1/100 000 cases, this would translate in at least 80 000 cases worldwide. The variant found in our patient has previously been described as disease causing for APRT deficiency in four cases. Reviewing the phenotype of these cases we find differences in terms of presentation and evolution, highlighting the variability in the APRT deficiency phenotype and underlining the fact that no correlation between phenotype and genotype was reported to date even for the same type of mutation. This case report shows us that the initiation of an adequate therapy is necessary even at advanced stages of the disease since it can improve our kidney outcome.