Prevalence and Clinical Profile of Septic Acute Kidney Injury in Steroid Responsive Nephrotic Syndrome in a Tertiary Care Hospital in India: A Prospective Observational Study

Background: Acute kidney injury (AKI) and Sepsis are well recognized complications of nephrotic syndrome. Systemic inflammatory response syndrome (SIRS) insult in the nephrotic background initiates interplay between inflammation and oxidative stress, leading to septic acute kidney injury (SAKI). There is hardly any data on the prevalence and clinical profile of SAKI in steroid-responsive nephrotic syndrome. The present study was conducted to know the prevalence and clinical profile of SAKI in steroid responsive nephrotic syndrome.

Methods: Study Design -a prospective observational cross-sectional study
Setting & Participants - the study was conducted at Dr B C Roy Post Graduate Institute of Pediatric Sciences, Kolkata, India. Consecutive children with steroid responsive nephrotic syndrome below 12 years were included after exclusion of congenital malformation of kidney and pre-existing chronic kidney disease between September, 2018 and July, 2020.
Exposure - sepsis identified by Sepsis-3 criteria in steroid responsive nephrotic syndrome
Outcomes - development of AKI

Results: Out of 235 subjects, 64 (27.23%) develop AKI. 59 (92.18%) of them developed septic AKI (SAKI). The proportion of sepsis associated AKI was 92.10%. Among the 59 subjects with SAKI, 40 (67.79%) had Sepsis and 19(32.20%) hadseptic shock. As per KDIGO AKI staging of 59 patients with SAKI–
38 (64.4%), 12(20.33%) and 9 (15.25%) subjects developed stage 1, stage 2 and stage 3 AKI respectively. Severity of AKI was associated with the severity of sepsis(p value <0.0000).
Clinical features included features of peritonitis, sepsis, or septic shock followed by prolongation of the oliguric phase of nephrotic syndrome, development of hypertension, azotemia and congestive heart failure in some cases. Diuresis followed with subsidence of edema, CCF, azotemia with treatment. Hypertension persisted for prolonged and variable period. Blood culture was positive in 15.3% subjects.Pneumococcus(44.44%),Klebsiella (33.33%), Pseudomonas(22.22%) and Sphingomonas (11.11%) were the isolates. Mortalityin sepsis induced AKIwas 6.77%. Duration of hospital stay, requirement of ICU care and mortality were higher in SAKI compared to non-SAKI group(p value 0.00005360, <0.0000001 and 0.02215 respectively).Thus, SAKI is found to be the most important complication of steroid responsive nephrotic syndrome in the present study.

Conclusion: Prevalence of AKI in steroid responsive nephrotic syndrome is common. Most of the AKI are associated with sepsis. Severity of sepsis which is determined by Sepsis-3 staging is correlated with severity of AKI which is expressed in terms of KDIGO AKI staging. SAKI is associated with increased length of hospital stay, increased frequency of ICU requirement and increased mortality making it the most important complication of steroid responsive nephrotic syndrome. However, this study has its limitations in terms of being a single centre study with relatively small number of subjects. Further studies are required with larger sample size and prolonged follow up.