Risk Factors for Acute Kidney Injury and Death in Patients Infected With the Yellow Fever Virus During the 2018 Outbreak in São Paulo, Brazil.

Introduction: There have been few studies investigating acute kidney injury (AKI) in patients with yellow fever (YF). The objective of this study was to identify the risk factors for AKI and death in such patients. Methods: We evaluated 95 consecutive critically ill adult patients with the sylvatic form of YF, as confirmed by reverse-transcriptase polymerase chain reaction, in Brazil. The outcome measures were AKI (as defined by Kidney Disease: Improving Global Outcomes [KDIGO] criteria) and in-hospital death. Results: Of the 95 patients, 73 (76.8%) had AKI and 59 (62.1%) died from it. A total of 70 patients (73.7%) required dialysis because of AKI. After adjusting for age, sex, and the Simplified Acute Physiology Score 3 (SAPS 3), we found that elevated fractional excretion of sodium and requiring dialysis were independent risk factors for in-hospital mortality and that proteinuria correlated with AKI-associated mortality. Conclusion: Our findings indicate that, in patients with sylvatic YF, AKI is common and is associated with significant mortality. The data presented here could prove useful for improving understanding of the pathogenesis of AKI in YF and informing decisions regarding the care of the affected patients.

Influence of low free thyroxine on progression of chronic kidney disease.

BACKGROUND: Hypothyroidism is highly prevalent in patients with chronic kidney disease (CKD) and has been associated with poorer clinical outcomes, including faster decline of kidney function. However, there is no consensus whether low free thyroxin (LFT) affects the rate of estimated glomerular filtration rate (eGFR) decline and how the presence of proteinuria influences the progression of renal dysfunction in hypothyroidism. METHODS: We assessed thyroid status, proteinuria, and progression of eGFR by Modification of Diet in Renal Disease equation and CKD-EPI equation in a cohort of CKD patients followed in general nephrology clinics. We estimated the association of LFT levels, and the degree of proteinuria on progression of eGFR. We adjusted for other covariables: age, gender, body mass index, diabetes, hypertension, HbA1c, uric acid, cholesterol, and triglycerides levels.. RESULTS: One thousand six hundred ten patients (64 ± 15 years, 46.8% men, 25.3% diabetic) were included. At beggnining of follow up eGFR was between 45 and 60, 30-45 and 15-30 ml/min/1.73m2 in 479 (29.8%), 551(34.2%), and 580(36.0%) patients, respectively. LFT levels were available at initial evaluation in 288(17.9%) patients and 735(48.5%) had assessment of proteinuria (19.6% with LFT vs. 15.4% without LFT, p = 0.032). Median follow-up time was of 21 months, and 1223(76%) had at least 1 year of follow up. Overall, eGFR decline per month was - 0.05(- 0.26, 0.23) ml/min/1.73m2, reaching 1.7(1.3, 2.4) ml/min/1.73m2 by the end of study period. Similar results were obtained using CKD-EPI. Multivariable mixed linear analysis showed that proteinuria and age were independently associated with eGFR decline, with no effect of LFT, and no interaction between proteinuria and LFT. In patients without proteinuria, there was an improvement of eGFR despite the presence of LFT. CONCLUSIONS: We confirmed a faster rate of eGFR declined in patients with proteinuria. However, despite the pathophysiological rational that hypothyroidism can lead to increased rate of CKD progression, we failed to demonstrate an association between LFT and rate of CKD progression. We conclude that the benefit of hypothyroidism treatment in CKD patients needs to be evaluate in prospective studies.