Background and aim In December 2019, a coronavirus 2019 (COVID-19) outbreak, caused by SARS-CoV-2, took place in Wuhan and was declared a global pandemic in March 2020 by the World Health Organization (WHO). It is a prominently respiratory infection, with potential cardiological, hematological, gastrointestinal and renal complications. Acute kidney injury (AKI) is found in 0.5-25% of hospitalized COVID-19 patients and constitutes a negative prognostic factor. Renal damage mechanisms are not completely clear. We report the clinical evolution of hospitalized COVID-19 patients who presented with AKI requiring attention from the Nephrology team in a tertiary hospital in Madrid, Spain. Methods This is an observational prospective study including all COVID-19 cases that required hospitalization and Nephrology management from March 6 th to May 12 th . We collected clinical and analytical data of baseline characteristics, COVID-19 and AKI evolutions. Results We analyzed 41 patients with a mean age of 66.8 years (SD 2.1), 90.2% males, and with a history of chronic kidney disease (CKD) in 36.6%. 56.1% of patients presented with sever pneumonia or acute respiratory distress syndrome (ARDS), and 31.7% required intensive care. AKI etiology was prerenal in 61%, acute tubular necrosis in the context of sepsis in 24.4%, glomerular in 7.3% and tubular toxicity in 7.3% of the cases. We reported proteinuria in 88.9% and hematuria in 79.4% of patients. 48.8% of patients required renal replacement therapy (RRT). Median length of stay was 12 days (interquartilic range 9-23) and 22% of the population died. Patients who developed AKI during hospital stay presented with higher C-reactive protein, Lactate dehydrogenase-LDH and D-dimer values, more severe pulmonary damage, more frequent intensive care unit-ICU admission, treatment with lopinavir/ritonavir and biological drugs and RRT requirement. Conclusions Hypovolemia and dehydration are a frequent cause of AKI among COVID-19 patients. Those who develop AKI during hospitalization display worse prognostic factors in terms of pulmonary damage, renal damage, and analytical findings. We believe that monitorization of renal markers as well as individualized fluid management can play a key role in AKI prevention.

Background/Aims: A recent alert from Spanish health authorities warned of a higher incidence of reported hypersensitivity reactions to hemodialysis membranes with polysulfone, in the 2017 review of acute reactions to dialyzers found only published reports in the 21^st century on polysulfone and its derivatives. The aim is to assess/evaluate the current incidence and characteristics of hypersensitivity reactions in hemodialysis patients. Methods: A retrospective multicentre study in 9 Spanish hospitals evaluated patients in whom a hypersensitivity reaction required a change in dialyzer membrane. Results: A total of 37 patients out of 1561 (2.37%) had hypersensitivity reactions and clinical, epidemiological and analytical data were available for 33 patients (2.11%). The membranes involved were polysulfone (n=23), polynephron (n=8), polyethersulfone (n=1) and polyacrylonitrile (n=1). This distribution reflected the frequency of use of membranes in the participating dialysis units. The reactions were described as type A in 18 cases and type B in 15 cases. There were no significant differences between the two types in clinical symptoms, the composition of the membrane involved, the method of sterilization, the season, or the time during the session in which they occurred. The most frequent symptom was dyspnea/breathlessness (64% of reactions). Eosinophilia was common (74%). 54% of the reactions occurred within the first 30 minutes of hemodialysis, 64% occurred during the first year of dialysis, and 54% required discontinuation of dialysis session. Cellulose triacetate was used as an alternative dialyzer in 78% of the cases. Conclusion: The incidence of hypersensitivity reactions was in the range found in reports from 20 years ago and is observed associated with synthetic membranes, not just polysulfones. Cellulose triacetate appears to be a good alternative for these patients.

Antecedentes y objetivo: En diciembre de 2019 surgió en Wuhan, China, la COVID-19 causada por SARS-CoV-2, declarada pandemia global por la OMS en marzo de 2020. Es una infección respiratoria con complicaciones a nivel cardiaco, hematológico, digestivo, neurológico y renal. El fracaso renal agudo (FRA) en pacientes hospitalizados por COVID-19 se presenta en el 0,5-25% y es un factor de mal pronóstico. Los mecanismos de afectación renal no están completamente aclarados. Presentamos la evolución clínica de pacientes ingresados por COVID-19 con FRA que requirieron atención por nefrología en un hospital terciario de la comunidad de Madrid, España. Métodos: Éste es un estudio observacional prospectivo de todos los casos que ingresaron por COVID-19 entre el 6 de marzo y el 12 de mayo de 2020 y requirieron atención por Nefrología. Se recogieron datos clínicos y analíticos de características basales, evolución de la COVID-19 y del FRA. Resultados: Se analizaron 41 pacientes con edad media de 66,8 años (DE 2,1), el 90,2% varones, y con enfermedad renal crónica previa en el 36,6%. El 56,1% presentaron neumonía grave o síndrome de distrés respiratorio agudo y el 31,7% requirió ingreso en UCI. El FRA fue de etiología prerrenal en el 61%, necrosis tubular aguda en contexto de sepsis en el 24,4%, glomerular en el 7,3% y por toxicidad tubular en el 7,3%. Se registró proteinuria en el 88,9% y hematuria en el 79,4%. El 48,8% de los pacientes requirió terapia de sustitución renal (TSR). La mediana de estancia fue de 12 días (RIC 9-23), y el 22% fallecieron-Los pacientes que desarrollaron FRA durante el ingreso presentaron valores más altos de proteína C-reactiva, LDH o dímero D, una afectación pulmonar más grave, más necesidad de ingreso en UCI, más tratamiento con lopinavir/ritonavir y fármacos biológicos y mayor necesidad de TSR. Conclusiones: La hipovolemia y deshidratación son una causa frecuente de FRA en pacientes COVID-19. Aquellos que desarrollan FRA intrahospitalario presentan un perfil de peor pronóstico respiratorio, analítico y renal. Creemos que la monitorización de marcadores renales, así como el manejo individualizado de la volemia pueden ser determinantes para prevenir el FRA.

Background Acute kidney injury (AKI) caused by cast nephropathy is associated with increased morbidity and mortality among patients with multiple myeloma (MM). High cut-off haemodialysis (HCO-HD) has proven to be effective in the removal of serum light chains but the effect on clinical outcomes, especially renal recovery, remains uncertain. Methods A systematic review and meta-analysis were performed examining all randomized controlled trials (RCTs) and observational studies (OBSs) assessing the effect of HCO-HD on clinical outcomes of patients with MM complicated by cast nephropathy–induced severe AKI. The primary outcome was all-cause mortality at the end of the study. The secondary outcomes included all-cause mortality at 12 months, HD independence and serum kappa and lambda light chain reduction. Pooled analysis was performed using random effects models. Results We identified five studies, comprising two RCTs and three retrospective cohort studies, including 276 patients with a mean follow-up of 18.7 months. The majority of the studies were of suboptimal quality and underpowered. Compared with patients treated with conventional HD, HCO-HD was not associated with a survival benefit at 12 months {five studies, 276 patients, relative risk [RR] 1.02 [95% confidence interval (CI) 0.76–1.35], I2 = 33.9%} or at the end of the studies at an average of 34 months [five studies, 276 patients, RR 1.32 (95% CI 0.71–2.45), I2 = 62.0%]. There was no difference in HD independence at 90 days [two trials, 78 patients, RR 2.23 (95% CI 1.09–4.55)], 6 months [two studies, 188 patients, RR 1.19 (95% CI 0.68–2.06)] or 12 months [two studies, 188 patients, RR 1.14 (95% CI 0.58–2.26)]. Patients receiving HCO dialysis, however, had a greater reduction in serum kappa [two studies, 188 patients, weighted mean difference (WMD) 46.7 (95% CI 38.6–54.7), I2 =  52.0%] and lambda [two studies, 188 patients, WMD 50.3 (95% CI 21.4–79.3), I2 = 95.1%] light chain levels. Conclusion Current evidence from RCTs and OBSs suggests HCO dialysis is able to reduce serum free light chains but makes no significant improvement in all-cause mortality and renal outcomes compared with conventional HD for patients with myeloma cast nephropathy. However, there is a trend towards better renal outcomes with the use of HCO dialysis. The lack of long-term data and the small sample sizes of the included studies limit this analysis. Therefore further large-scale RCTs with longer follow-up are needed to assess the effect of HCO dialysis on clinical outcomes in patients with myeloma cast nephropathy.