Chronic Kidney Disease and Hepatitis C virus.

Introduction and Objectives

Hepatitis C virus (HCV) is an independent risk factor (RF) for chronic kidney disease (CKD) and for progression to end-stage renal disease (ESRD). The objective is to analyze the known RFs for CKD and progression to ESRD in patients with HCV and those specific to this population.

Materials and Patients

A prospective cohort study was conducted to identify the RFs for kidney damage and progression to CKD in a cohort with chronically infected HCV. The known RFs were analyzed: age over 65 years, diabetes, essential hypertension as the main RFs, in addition to obesity and RFs related to HCV infection prevalent in this population, such as blood transfusion, sexual promiscuity, intravenous drug users (IVDU). CKD was determined when functional alterations of the kidney were found for more than 3 months. The estimation of glomerular filtration rate (eGFR) was performed with the renal function calculator of the Spanish Society of Nephrology that uses the corrected Cockcroft-Gault formula where <60 ml/min/1.73m2 is considered CKD. The normal range of eGFR is 90-100 mL/min/1.73m2, considering hyperfiltration above this. Diabetes and hypertension, transfusions, IVDU were self-reported by the patient for sexual promiscuity; the definition of the World Health Organization was considered, determining it when one has more than two sexual partners in less than 6 months; obesity was determined with the body mass index.

Results

Of 130 with chronic HCV infection, we found 51% were men with a mean age of 54 years. Among the known RFs, we identified age >65 in 21%, with diabetes at 26% and essential hypertension at 27%; among those associated with this population, 100% had chronic infection with HCV, a history of blood transfusion and blood products in 45%, IVDU in 25%, with obesity in 26%. About the different stages of CKD, we find 60% of the population in hyperfiltration ranges with an eGFR >100 mL/min/1.73m2. Hyperfiltration was associated first with obesity, in 70% of obese people, followed by 47 and 46% with diabetes and hypertension, respectively, in 32% with age >65 it is noteworthy that more than half of the patients with a history of transfusion in the IVDU, 59% and 54% had this finding. In addition, 21% of the total population evaluated was in stage 2 with an eGFR between 60-89 mL/min/1.73m2. Only 8% had an eGFR in normal ranges between 90-100 mL/min/1.73m2

Conclusions

HCV is recognized as an independent RF for the development and progression to CKD; the intentional search for known RFs in this population will help reduce the progression to ESKD. The finding in this study of hyperfiltration is a little-explored fact, which deserves further study.