Glomerulonephritis associated with hepatitis C virus infection:

Role of fluid-phase complement system regulation in the development of hepatitis C virus-associated glomerulonephritis

OBJECTIVES

It is not known why only some hepatitis C virus (HCV) infected patients develop glomerulonephritis (GN). Therefore, we investigated the role of soluble complement regulators in the development of HCV associated GN.

METHODS

Patients with HCV associated GN who were admitted to our nephrology unit between July 2016 and July 2018 were recruited to the study (group 1). Two other age and sex matched groups were studied as control groups: patients with HCV without GN (group 2) and healthy HCV negative volunteers (group 3). There were 26 participants in each of the three groups at the end of the recruitment period. An assay of serum fluid-phase complement regulators was performed using enzyme linked immunosorbent assay technique. Three complement single nucleotide polymorphisms (SNPs) were analyzed using real time polymerase chain reaction (Taqman; thermo fisher scientific): rs2230199 and rs1047286 for complement 3 (C3) and rs800292 for complement factor H (CFH).

RESULTS

Serum levels of complement 4 binding protein (C4BP) were significantly lower in group 1 (median 70 ng/ml) than in groups 2 (median 88.8 ng/ml) and 3 (median 82.8 ng/ml) with p value of 0.007. The minor allele (allele A) of rs800292 for CFH was significantly higher in group 2 and group 3 (G 54% and A 46%) than in group 1 (G 73% and A 27%), p = 0.04.

CONCLUSIONS

Low C4BP levels are associated with GN in HCV infected patients. In addition, rs800292 SNP in CFH protects against GN in patients with HCV.

Transplantation in the patient with hepatitis C

Hepatitis C virus (HCV) infection is the most frequent cause of liver disease after renal transplantation. Its clinical course is irrelevant in the short term, except for rare cases of fibrosing cholestatic hepatitis. However, in the long run, HCV infection can lead to major liver complications. Because interferon (IFN) is generally contraindicated in renal transplant patients, the best approach is to treat patients on dialysis. Until more information with pegylated-IFN is available, the use of alpha-IFN monotherapy is recommended. Most of the patients with sustained virological response remain HCV RNA negative after transplantation. HCV-positive renal transplant patients have a higher risk for proteinuria, chronic rejection, infections and post-transplant diabetes (PTDM). Long-term patient- and graft-survival rates are lower in HCV-positive patients. Mortality is higher, mainly as a result of liver disease and infections. HCV can contribute to the development of certain neoplasias such as post-transplant lymphoproliferative disease (PTLD). HCV infection is also an independent risk factor for graft loss. PTDM, transplant glomerulopathy and HCV-related glomerulonephritis can contribute to graft failure. Despite this, transplantation is the best option for end-stage renal disease in HCV-positive patients. Several measures to minimize the consequences of HCV infection have been recommended. Adjustment of immunosuppression and careful follow up in the outpatient clinic for early detection of HCV-related complications are mandatory.

Chronic kidney disease as a global public health problem: approaches and initiatives - a position statement from Kidney Disease Improving Global Outcomes

Chronic kidney disease (CKD) is increasingly recognized as a global public health problem. There is now convincing evidence that CKD can be detected using simple laboratory tests, and that treatment can prevent or delay complications of decreased kidney function, slow the progression of kidney disease, and reduce the risk of cardiovascular disease (CVD). Translating these advances to simple and applicable public health measures must be adopted as a goal worldwide. Understanding the relationship between CKD and other chronic diseases is important to developing a public health policy to improve outcomes. The 2004 Kidney Disease Improving Global Outcomes (KDIGO) Controversies Conference on 'Definition and Classification of Chronic Kidney Disease' represented an important endorsement of the Kidney Disease Outcome Quality Initiative definition and classification of CKD by the international community. The 2006 KDIGO Controversies Conference on CKD was convened to consider six major topics: (1) CKD classification, (2) CKD screening and surveillance, (3) public policy for CKD, (4) CVD and CVD risk factors as risk factors for development and progression of CKD, (5) association of CKD with chronic infections, and (6) association of CKD with cancer. This report contains the recommendations from the meeting. It has been reviewed by the conference participants and approved as position statement by the KDIGO Board of Directors. KDIGO will work in collaboration with international and national public health organizations to facilitate implementation of these recommendations.

Treatment of hepatitis C-virus-related glomerulonephritis

Membranoproliferative glomerulonephritis (MPGN) associated with type II cryoglobulinemia is the predominant type of hepatitis C virus (HCV)-related glomerulonephritis. The blockade of the renin-angiotensin system, as well as a combined anti-HCV therapy that associates standard or pegylated alpha-interferon with ribavirin, are mandatory in all patients experiencing an HCV-related glomerulonephritis. In patients with nephrotic-range proteinuria and/or progressive renal failure, immunosuppressive therapy is necessary. Rituximab, the monoclonal anti-CD20 antibody that selectively targets the B cells, seems to be as least as efficient as cyclophosphamide. Because it is also better tolerated, it should be preferred to cyclophosphamide. During the acute phase, plasmapheresis and steroid pulses can be used. However, future prospective, controlled, and randomized studies are still required to establish evidence-based guidelines to treat HCV-related glomerulopathies.