<b><i>Introduction:</i></b> Cytokine storm control is the main target for improving severe COVID-19 by using immunosuppressive treatment. Effective renal replacement therapy (RRT) could give us an advantage removing cytokines in patients with RRT requirements superimposed on COVID-19. <b><i>Methods:</i></b> This is a prospective observational study in COVID-19 patients who required hemodialysis (HD). Patients were assigned to online hemodiafiltration (OL-HDF) and expanded HD (HDx) according to Brescia group recommendations. We measured several cytokines, β2 microglobulin and albumin levels pre/post-dialysis and on 1st–2nd week. We compared levels among both techniques and control group (HD without COVID-19). <b><i>Results:</i></b> We included 26 patients: 18 with COVID-19 on RRT (5 of them had acute kidney injury [AKI]) and 8 controls. We confirm higher cytokine levels in COVID-19 patients than controls and even higher in patients with AKI than in those with chronic kidney disease. Most cytokines raised during HD session, except IL-10 and TNFα. IL-10 was eliminated by any dialysis technique, while clearance of TNFα was higher in the HDx group. HDx achieved a deeper normalization of cytokines and β2 microglobulin reduction. Mortality was higher in the OL-HDF group than the HDx group. <b><i>Discussion:</i></b> Not all cytokines behave equally along HD session. The following characteristics should be taken into account, such as intrinsic kinetic profile during a HD session. HDx seems to get better performance, probably due to the combination of different factors; however, we did not reach statistical significance due to the small sample size, dropout, and reduction of AKI incidence during the 2nd pandemic wave. <b><i>Conclusion:</i></b> HDx appears to provide better clearance for TNFα and β2 microglobulin during HD session and associates lower mortality. We propose the HDx technique for COVID-19 patients with RRT requirements since it seems to be safe and more effective than OL-HDF. Further studies are still needed, but we hope that our preliminary data may help us in future pandemic waves of SARS-CoV-2 or other viruses still to come.

BACKGROUND AND AIMS Acute kidney failure (AKI) is a well-known risk factor in coronary care unit (CCU) and postoperative patients. We aim to analyse their role in a multicentre database (DB) from a public regional health system (6 million inhabitants). METHOD Observational, retrospective study, including all hospital admissions between January 2013 and December 2014 in all referral hospitals in Madrid. We grouped into three categories, admissions due to AKI (ON-AKI), AKI during stay (HOSP-AKI) secondary to other disease and admissions without AKI (no-AKI); ICD-9 code was 584. Admission from patients aged under 16, women to give birth or previous renal replacement therapy (RRT) were excluded. Study was approved by the ethics committee. RESULTS Of the 419 851 admissions registered in 2 years, 6.7% had an associated AKI (0.6% on arrival AKI and 6.1% during admission AKI). Patients admitted for AKI are older (ON-AKI: 74.8 years versus HOSP-AKI: 77.9 versus no-AKI: 63.6), with greater comorbidity (Charlson index 2.9 versus 3.1 versus 1.7); patients had more previous CV events (28.5% versus 46.8 versus 21.0), diabetes mellitus (34.1% versus 30.4 versus 17.1) and a higher prevalence of previous chronic kidney disease-CKD (41.3 versus 31.5 versus 4.9%). AKI kidney failure lengthens hospital stay by 3.2 days 95% confidence interval (95% CI) (2.8–3.5) after adjust by age, gender, Charlson index, surgery and major diagnostic categories. Admissions with AKI are usually unscheduled and have a longer hospital stay (9.6 ON-AKI versus 12.6 HOSP-AKI versus 7.1 days in no-AKI admission). More patient died during hospital stay in AKI group (14.4% ON-AKI; 22.9 HOSP-AKI versus 3.5% No-AKI) and although 4.3% of admission needed dialysis, only 0.5% started a chronic RRT during admission. Principal risk factor for developing secondary AKI (R2 = 16%) is previous CKD [OR 3.6; (3.48–3.74)], after corrected by age, male, the Charlson index and non-surgical admission. Mortality risk for patients with an admission for AKI (R2 = 17%), corrected for age, sex, comorbidity, previous CKD, and type of admission is OR: 1.8 95% CI (1.57–2.08); secondary AKI is OR 3.73 (3.59–3.88) than no-AKI admission. CONCLUSION AKI is a huge burden for health system and patients, and associates significant longer stay, cost and a higher mortality. Main factor to develop secondary AKI is age and previous CKD.

BACKGROUND AND AIMS The incidence of chronic kidney disease (CKD) in patients with lung transplantation (LTx) has increased over the last decades. Progression factors recognized in the development of CKD are: older age and comorbidity of recipients, immunosuppressive (IS) toxicity and longer survival. There is a lack of specific information about other risk factors or specific preventive management of CKD. METHOD Retrospective, single-centre study including all patients with LTx on Nephrology outpatient clinic among 2007 and 2020. Demographic, comorbidity and intercurrent events, renal function impairment, proteinuria and IS treatment were analyzed. We defined composite renal event (MARE) as renal replacement therapy (RRT), death or doubling serum creatinine. RESULTS A total of 69 LTx receptors (79.4% double LTx) were followed in a dedicated outpatient nephrology clinic. A total of 52.2% male, mean age at LTx 48.3 years (SD 16.6). Etiology of lung disease: cystic fibrosis (30.4%), obstructive lung disease or emphysema (33.3%) and interstitial disease (30.4%). After LTx, as complications, infection was the most frequent event (89.7%) and 49.3% presented neoplasic illness. The mean time from LTx until first nephrologist evaluation was 6.6 years (2 months–19.9 years) and main comorbidities were: hypertension (81.2%), diabetes mellitus (52.2%), dyslipidemia (50.7%), 60.3% former smokers and 26.1% had suffer from a previous CV event. After 1 year of LTx, mean eGFR decreased to 49.8 mL/min, which means that only in the first year after LTx there is a loss of ∼50% of mean kidney function. Factor associated with impaired kidney function at the first year after LTxw was cystic fibrosis (higher percentage in the rapid progression group). At first evaluation by Nephrology, the mean eGFR was 30.9 mL/min (SD 15.3), with a CKD distribution: 39.4% CKD 3; 45.5% CKD 4 and 12.1% CKD 5 (&lt;15). Clinical study and biopsy define CKD etiologies: CNI toxicity (68.1%) thrombotic microangiopathy (11.6%), tubular (10.1%), vascular (7.3%) and glomerulopathies (2.9%). A total of 88.4% patients reached MARE at the end of the study. A total of 24 patients required RRT (mean time since LTx 9.2 years) and thereafter, 10 received a kidney transplantation (KTx). In Dyalisis group, a higher mortality was observed versus no dialysis group (24 versus 2.2%), a higher percentage of vascular origin disease with a further deterioration of eGFR at the time of referral to Nephrology. At the end of follow-up, 15 patients died (14 were in RRT), 5 continued on HD and 5 with a functional KTx, and 44 patients were still without RRT. CONCLUSION