Cryoglobulin types and rheumatoid factors associated with clinical manifestations in patients with hepatitis C virus infection

Epidemiology, risk factors, and pathogenesis associated with a superbug: A comprehensive literature review on hepatitis C virus infection

Viral hepatitis is a major public health concern. It is associated with life threatening conditions including liver cirrhosis and hepatocellular carcinoma. Hepatitis C virus infects around 71 million people annually, resultantly 700,000 deaths worldwide. Extrahepatic associated chronic hepatitis C virus accounts for one fourth of total healthcare load. This review included a total of 150 studies that revealed almost 19 million people are infected with hepatitis C virus and 240,000 new cases are being reported each year. This trend is continually rising in developing countries like Pakistan where intravenous drug abuse, street barbers, unsafe blood transfusions, use of unsterilized surgical instruments and recycled syringes plays a major role in virus transmission. Almost 123–180 million people are found to be hepatitis C virus infected or carrier that accounts for 2%–3% of world’s population. The general symptoms of hepatitis C virus infection include fatigue, jaundice, dark urine, anorexia, fever malaise, nausea and constipation varying on severity and chronicity of infection. More than 90% of hepatitis C virus infected patients are treated with direct-acting antiviral agents that prevent progression of liver disease, decreasing the elevation of hepatocellular carcinoma. Standardizing the healthcare techniques, minimizing the street practices, and screening for viral hepatitis on mass levels for early diagnosis and prompt treatment may help in decreasing the burden on already fragmented healthcare system. However, more advanced studies on larger populations focusing on mode of transmission and treatment protocols are warranted to understand and minimize the overall infection and death stigma among masses.

The Kunkel legacy and hepatitis C virus infection

In commemoration of Henry Kunkel's 100th birthday, the effect of his legacy on the investigation of hepatitis C virus is recounted. The delineation of a major cross-idiotype (WA) among patients with essential mixed cryoglobulinemia led to the discovery that HCV was the etiologic agent for this disease. Studies of the cryoglobulins led to the discovery that WA RF reacted specifically with HCV-VLDL like particles that on electronmicroscopy and binding studies appeared to be the virion within a lipid shell. This particle mediates cell entry via LDLr and may serve to avoid the immune response by masking the virion. In addition, the WA B cell may be a prognostic marker for cutaneous vasculitis and B cell malignancy in HCV-infected patients. In commemoration of Henry Kunkel's 100th birthday, this is an account of how his legacy had a role in the investigation of hepatitis C virus (HCV) infection. There is a bit of a historical basis for the legacy of this great immunologist having a role in virology. He began his research career studying hepatitis. Later he worked with HCV in his studies of mixed cryoglobulins although he didn't know it at the time. There may also have been a Kunkel historical basis for why he accepted me as fellow in his laboratory considering that my credentials paled in comparison with those of the fellows and PhD students in his laboratory. Like Henry I was drafted into the Navy following my internship, I had had minimal research experience in medical school and only one minor publication, and I had a passion for clinical investigation. It may have been fortuitous that while on active duty at the Bayonne NJ Naval Base I visited Henry Kunkel in my Navy uniform and told him I was interested in studying SLE. I did not know at the time the dramatic role the Navy had played in his career or that one of his major training goals was to teach MDs to use clinical observation as a focus for delineating disease mechanisms in the laboratory. When I started work in the laboratory on discharge from the Navy, the first thing he told me was that it took five years to make a clinical investigator so I might as well get a Rockefeller University PhD while working in his laboratory. I was sure I would leave the laboratory after two years so I declined his offer. I did not leave until six years later!

Hepatitis C-associated cryoglobulinemic glomerulonephritis with crystalline deposits

Infection with hepatitis C virus has been associated with a number of extrahepatic manifestations, including kidney disease. Of the glomerular pathologic states described with hepatitis C virus infection, cryoglobulinemic glomerulonephritis is the most prevalent. On kidney biopsy, cryoglobulinemic glomerulonephritis has a variable appearance, with a membranoproliferative pattern of injury as the most common light microscopic finding. Ultrastructurally, curved and paired microtubules are the most characteristic finding, but these also can be variable. We present a case of cryoglobulinemic glomerulonephritis with distinct and highly unusual ultrastructural findings.

Pegylated interferon-α, ribavirin, and rituximab combined therapy of hepatitis C virus–related mixed cryoglobulinemia: a long-term study

This study illustrates the use and efficacy of a combination of pegylated interferon-α (Peg-IFN-α) and ribavirin (RBV), with or without rituximab (RTX), in hepatitis C virus (HCV)–related mixed cryoglobulinemia (MC). Twenty-two patients with HCV-related MC received Peg-IFN-α (2a: 180 μg or 2b: 1.5 μg/kg) weekly plus RBV (1000 or 1200 mg) daily for 48 weeks, and RTX (375 mg/m2) once a week for 1 month followed by two 5-monthly infusions (termed PIRR). Fifteen additional patients received Peg-IFN-α/RBV with the same modalities as the PIRR schedule. Complete response was achieved in 54.5% (12/22) and in 33.3% (5/15) of patients who received PIRR and Peg-IFN-α/RBV, respectively (P < .05). Clearance of HCV RNA and conversion of B-cell populations from oligoclonal to polyclonal in liver, bone marrow, and peripheral blood was maintained for up to 3 years in 10 of 12 (83.3%) and in 2 of 5 (40%) patients receiving PIRR and Peg-IFN-α/RBV, respectively (P < .01). Cryoproteins in 22.7% (5/22) of patients with PIRR and in 33.3% (5/15) with Peg-IFN-α/RBV persisted despite sustained HCV RNA clearance. No response occurred in remaining 5 patients of both groups. PIRR therapy is well tolerated and more effective than Peg-IFN-α/RBV combination in HCV-related MC. Its effect may last for more than 3 years.

Schistosoma mansoni coinfection could have a protective effect against mixed cryoglobulinaemia in hepatitis C patients

BACKGROUND/AIM

The association between mixed cryogloblinaemia and chronic hepatitis C virus (HCV) infection has been established. However, the factors underlying its great geographical heterogeneity of prevalence have not yet been identified. Concomitant HCV and Schistosoma mansoni infections are common in Egypt. Chronic helminthic infections have been found to decrease the incidence and manifestations of immune-related diseases. To date, no study has focused on the influence of S. mansoni coinfection on the risk of cryoglobulinaemia in hepatitis C patients.

METHODS

A cohort of 119 consecutively recruited chronic hepatitis C-infected patients was studied. Patients' sera were assessed for S. mansoni antibodies and cryoglobulins (CGs) were determined and characterized.

RESULTS

Cryoglobulins were detected in 18 of 119 patients (15.1%) included in this study. They were detected in 12 of 45 hepatitis C (26.7%) and six of 74 coinfected patients (8.1%), which was statistically significant, P=0.01. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were also found to be significantly lower in the CG-positive group compared with the CG-negative group, P=<0.01. CGs were detected in seven of 21 (33.3%) and in 11 of 98 (11.2%) hepatitis C female and male patients, respectively, indicating a significantly positive association with the female gender, P=0.02. A logistic regression adjusted for gender, AST and ALT showed that hepatitis C patients without schistosomal coinfection are more likely to have cryoglobulinaemia, odds ratio=4.12, 95% confidence interval=1.42-11.95.

CONCLUSION

There is an apparent protective effect of S. mansoni coinfection against mixed cryoglobulinaemia in chronic hepatitis C patients.

Cryoglobulinemia and renal disease

PURPOSE OF REVIEW

Cryoglobulinemia occurs in a variety of clinical settings including lymphoproliferative disorders, infection and autoimmune disease. The worldwide pandemic of hepatitis C virus infection has resulted in a significant increase in its extrahepatic complications including cryoglobulinemia and renal disease. Here we review the types of cryoglobulins, mechanisms of cryoglobulin formation, links between hepatitis C virus and renal disease, and current approaches to therapy.

RECENT FINDINGS

The prevalence of cryoglobulinemia in hepatitis C virus-infected individuals is surprisingly large and may be found in more than 50% of some infected subpopulations. Most of these patients will not have overt renal disease, but there is a population of unknown size of patients with subclinical glomerular disease that has the potential to become clinically significant. In cases of hepatitis C virus-associated cryoglobulinemia, treatment remains focused on eradication of viremia, but interventions directed at B lymphocytes are increasingly utilized. The mechanisms of cryoglobulin formation and renal injury remain largely obscure, but recent evidence implicates the innate immune system in the initiation of disease.

SUMMARY

The most common renal injury associated with hepatitis C virus infection, in patients both with and without evidence of cryoglobulinemia, is membranoproliferative glomerulonephritis. There has been increasing focus on defining the mechanisms that link these processes and the evolution of renal injury in all clinical settings of cryoglobulinemia.