Hepatitis C virus infection in nephrology patients

Opportunities for treatment of the hepatitis C virus-infected patient with chronic kidney disease

The prevalence of hepatitis C virus (HCV) infection amongst patients with chronic kidney disease (CKD) and end-stage renal disease exceeds that of the general population. In addition to predisposing to the development of cirrhosis and hepatocellular carcinoma, infection with HCV has been associated with extra-hepatic complications including CKD, proteinuria, glomerulonephritis, cryoglobulinemia, increased cardiovascular risk, insulin resistance, and lymphoma. With these associated morbidities, infection with HCV is not unexpectedly accompanied by an increase in mortality in the general population as well as in patients with kidney disease. Advances in the understanding of the HCV genome have resulted in the development of direct-acting antiviral agents that can achieve much higher sustained virologic response rates than previous interferon-based protocols. The direct acting antivirals have either primarily hepatic or renal metabolism and excretion pathways. This information is particularly relevant when considering treatment in patients with reduced kidney function. In this context, some of these agents are not recommended for use in patients with a glomerular filtration rate < 30 mL/min per 1.73 m². There are now Food and Drug Administration approved direct acting antiviral agents for the treatment of patients with kidney disease and reduced function. These agents have been demonstrated to be effective with sustained viral response rates comparable to the general population with good safety profiles. A disease that was only recently considered to be very challenging to treat in patients with kidney dysfunction is now curable with these medications.

Evaluation of the Pharmacokinetics and Renal Excretion of Simeprevir in Subjects with Renal Impairment

BACKGROUND

Simeprevir is a N3/4 protease inhibitor approved for the treatment of hepatitis C virus (HCV) infection. HCV prevalence is higher in patients with chronic kidney disease compared with the general population; safe and efficacious therapies in renal impairment are needed.

OBJECTIVES

To evaluate simeprevir renal excretion in healthy subjects and to compare the simeprevir steady-state pharmacokinetics between subjects with severe renal impairment and healthy subjects.

METHODS

In the mass balance study, healthy adults received a single 200-mg dose of (14)C-simeprevir; radioactivity in the urine and feces was quantified until concentrations were <2% of the administered dose and seven or more stools were produced. In the pharmacokinetic study, non-HCV-infected adults with severe renal impairment (estimated glomerular filtration rate ≤29 mL/min/1.73 m(2)) and matched healthy subjects (estimated glomerular filtration rate ≥80 mL/min/1.73 m(2)) received 150 mg simeprevir for 7 days. Pharmacokinetic analysis was performed post-dose on Day 7.

RESULTS

(14)C-simeprevir recovery from the urine was low (0.009-0.138% of total dose). The minimum plasma concentration, maximum plasma concentration, and area under the plasma concentration-time curve at 24 h were 71, 34, and 62% higher, respectively, in subjects with severe renal impairment compared with healthy subjects. The mean fraction of simeprevir unbound to protein was <0.0001 (all subjects). Most adverse events were grade I or II; one subject with renal impairment who was receiving fenofibrate presented with grade 3 rhabdomyolysis.

CONCLUSIONS

Simeprevir plasma concentrations were mildly elevated in subjects with severe renal impairment. The results suggest that simeprevir may be administered without dose adjustment in patients with renal impairment.

Epidemiology of chronic kidney diseases in the Republic of Guinea; future dialysis needs

Background: Chronic kidney disease (CKD) is increasing worldwide and can lead to end-stage renal disease (ESRD).

Objectives: Because few patients with ESRD in the Republic of Guinea have access to haemodialysis, we retrospectively evaluated the prevalence of CKD, ESRD and access to supportive therapies.

Patients and Methods: 579 CKD patients (304 males; mean age: 44 ± 16 years) were admitted into Conakry nephrology department, the only centre in the Republic of Guinea, between 2009 and 2013. Most patients (63%) resided within Conakry (the capital), 12.5% came from lower Guinea, 11.7% from middle Guinea, 7.9% from upper Guinea and 4.8% from forest Guinea.

Results: Reasons for referral were increased serum creatinine (49.5%), hypertension (27%) and diffuse edema (17%). Also, 11% were diabetic, 12.5% were smokers, 17% were HIV-positive, 8.3% were HBV-positive and 15% were HCV-positive. The most frequent symptom at admission was nausea/vomiting (56%). Upon admission, 70.5% of patients already had ESRD. Although no kidney biopsies were performed it was assumed that 34% and 27% of patients had vascular nephropathy and chronic glomerulonephritis, respectively. Of the 385 ESRD patients, only 140 (36.3%) had access to haemodialysis (two sessions/week, 4 hours each). Most patients that received haemodialysis resided within the Conakry region (P < 0.0001). There were significant associations between mortality and (i) terminal stage of CKD (P = 0.0005), (ii) vascular nephropathy (P = 0.002), and (iii) nephropathies of unknown origin (P = 0.0001).

Conclusions: A fourfold increase in haemodialysis machines is needed in Conakry, plus four new nephrology/haemodialysis centres within the Republic of Guinea, each holding ≥30 haemodialysis machines.