Clinicopathological Study of Chronic Kidney Disease of Unknown Etiology in Odisha

Chronic kidney disease (CKD) is emerging as a serious health problem in Odisha, India. A new form of severe CKD affecting adults, not due to traditional risk factors like diabetes, hypertension, glomerulonephritis, has been reported in Sri Lanka, Central America, and Egypt in the last two decades. This has been named CKD of unknown origin (CKDu), and it is fatal due to late recognition and rapid disease progression. The aim of the study was to elucidate the association between different sociodemographic, and biochemical parameters with renal morphology in CKD of unknown origin patients.

A cross-sectional study was conducted on 124 consecutive patients with CKD from the period January 2018 to December 2018. Patients in the age group 18-60 years who met clinical criteria for CKD were included. Participants answered a questionnaire. After the necessary history, clinical evaluation, and blood and urine analyses, a kidney biopsy was undertaken. Kidney biopsy was feasible in 51 patients as the rest 61 patients had shrunken kidneys and 12 patients did not give consent. Patients with diabetes mellitus (DM), hypertension, glomerulonephritis, polycystic kidney disease, obstructive kidney disease or any other congenital diseases, snakebite, pregnancy, malignancy, gout, primary hyperparathyroidism, infectious diseases like human immunodeficiency virus (HIV), TB, Hepatitis B and C, malaria, syphilis, leprosy and coagulopathies were excluded. Among the 51 patients, 23 had CKDu, 25 had chronic glomerulonephritis and three biopsies were inconclusive.

The mean age of CKDu patients was 36.78 ± 9.85 years. Males (73.9%) were predominantly affected. A family history of CKD was seen in 82.6% of CKDu cases. Hyponatremia and hypokalemia were predominant biochemical abnormalities in our CKDu cases. Binary logistic regression showed rural residence, family history of CKD, exposure to smoke from burning coal, charcoal, or biomass fuels, low socioeconomic status, and low body mass index were strongly associated with CKDu. There was an increased risk of developing CKDu in persons with a family history of CKD [p = 0.003, odds ratio (OR)- 17.58], persons exposed to smoke from burning coal, charcoal or biomass fuels (p = 0.003, OR- 32.4), and patients with low socio-economic status (p = 0.001, OR- 15.87). Interstitial fibrosis (IF), interstitial inflammation with mononuclear infiltration, tubular atrophy (TA), and global glomerulosclerosis (GS) were pertinent histopathological findings in our study.

There is no strong evidence for a single cause for CKDu, and multiple environmental, occupational and social factors are probably involved. We need to design consistent and comparative multisite studies to identify etiologies of CKDu, across high-risk populations that may help elucidate the importance of region-specific vs global risk factors.