Hepatitis C virus in patients with cryoglobulinemia type II

Regression of monoclonal B-cell expansion in patients affected by mixed cryoglobulinemia responsive to alpha-interferon therapy

BACKGROUND

Several authors have reported on the effectiveness of alpha-interferon (IFN-alpha) in the treatment of patients with mixed cryoglobulinemia. This prompted the authors to investigate the long term effects of this drug on clinical, hematologic, and virologic parameters in a group of 20 patients (13 women and 7 men) affected by mixed cryoglobulinemia.

METHODS

In all patients, bone marrow biopsy, phenotyping of marrow cells, and polymerase chain reaction (PCR) immunoglobulin gene rearrangement in peripheral blood lymphocytes were performed before therapy and at the end of the follow-up. A liver biopsy was obtained in patients with biochemical signs of chronic liver disease. The presence of hepatitis C virus (HCV) RNA in serum was assessed by detection of anti-HCV antibodies, and by PCR amplification of the 5' untranslated region of HCV. The HCV genotype was also determined by PCR amplification of the core region of the virus with type-specific primers. The treatment schedule followed by all patients was 3 million units of recombinant IFN-alpha 2b 3 times weekly for 1 year.

RESULTS

In 6 patients, the marrow histology before therapy showed a massive (more than 50%) monomorphous infiltration by plasmacytoid lymphocytes, indicating the presence of low grade non-Hodgkin's lymphoma. Anti-HCV antibodies were present in 19 (95%) subjects, and HCV-RNA was detectable in all patients. In addition, all patients affected by Type II mixed cryoglobulinemia showed a monoclonal B-cell expansion in peripheral blood mononuclear cells (PBMC). With therapy, 5 patients (25%) achieved a complete response and 11 patients (55%) a partial response, whereas minor responses were observed in the remaining 4 patients (20%). One of the complete responders and all patients showing partial responses relapsed a few months after therapy withdrawal. At the end of the follow-up, four patients had obtained a complete remission. Bone marrow examination showed that B-lymphocytic monoclonal infiltrate disappeared in three patients. Moreover, these three patients had become negative for B-cell expansion in PBMC. Lack of response, or relapse, was associated with the presence of Type II HCV.

CONCLUSIONS

HCV may be the cause of mixed cryoglobulinemia. The disease is associated with a high prevalence of bone marrow B-cell lymphomas. IFN-alpha appears to be an effective agent for the treatment of mixed cryoglobulinemia. It also seems able to determine regression of the lymphoproliferative disorder. The HCV genotype appears to be the most important predictive factor for the response to antiviral therapy.

Peripheral neuropathy associated with essential mixed cryoglobulinaemia: a role for hepatitis C virus infection?

BACKGROUND

The prevalence of hepatitis C virus (HCV) infection has been estimated at 43 to 84% in patients with essential mixed cryoglobulinaemia in recent large series. Some of these cases have been successfully treated with interferon-alpha. The objective was to evaluate the prevalence and the possible role of HCV infection in essential mixed cryoglobulinaemia.

METHODS

Fifteen patients (eight men and seven women; mean age: 61.2 (SD 16.5) years) with peripheral neuropathy (10 polyneuropathies and five multifocal mononeuropathies) and essential mixed cryoglobulinaemia were tested for serum anti-HCV antibodies.

RESULTS

Antibodies were found in 10 of 15 patients involving either polyneuropathies (seven patients) or multifocal mononeuropathies (three patients). Electrophysiological studies and teased nerve fibre studies (in seven patients) allowed neuropathies to be classified as predominantly sensory axonopathies. Compared with HCV-negative (HCV -) patients, HCV-positive (HCV +) patients had a more pronounced and more widespread motor deficit; motor nerve conduction velocities in peroneal and median nerves were more impaired in HCV + patients, although significance was not reached except for the mean value of the amplitude of the compound muscle action potentials of the median nerves (P < 0.05); necrotising vasculitis was found in two of nine nerve biopsies from the HCV + patients studied and in none of the three HCV - patients. In addition, HCV + patients had more frequent cryoglobulin related cutaneous signs, higher aminotransferase and serum cryoglobulin concentrations, lower total haemolytic complement concentrations, and more frequent presence of rheumatoid factor. A liver biopsy performed in eight HCV + patients disclosed a range of lesions, from chronic active hepatitis (six patients) to persistent hepatitis (two patients). Lastly, treatment with interferon-alpha conducted over six months in two patients seemed to improve the peripheral neuropathy.

CONCLUSIONS

Patients with peripheral neuropathy and essential mixed cryoglobulinaemia should be tested for anti-HCV antibodies to determine the appropriate treatment.

Bilateral forefoot ischemia as a premonitory symptom of mixed cryoglobulinemia

Cryoglobulins are composed of cold-sensitive immunoglobulins that precipitate upon cooling. As the cutaneous vasculature of the extremities is commonly exposed to colder temperatures than the body core, this precipitation often occurs in cutaneous, or even digital vessels. Hyperviscosity from the precipitated proteins can incite local thrombosis in otherwise normal vessels, which is manifested clinically as ischemic ulceration. In previously injured vessels, as seen with atherosclerotic occlusive disease, cryoglobulin precipitation can lead to thrombosis of larger vessels, with the consequence being more severe ischemic necrosis. A case of bilateral forefoot ischemia is presented where the precipitating cause of the gangrenous changes appears to be the development of a mixed cryoglobulinemia and a B-cell lymphoma. Tibial angioplasty, plasmaphoresis, and chemotherapy directed at the B-cell lymphoma allowed limb salvage with bilateral transmetatarsal amputations.

Cryoglobulinemia and cutaneous leukocytoclastic vasculitis with hepatitis C virus infection

BACKGROUND

Mixed cryoglobulinemia (MC) is a systemic disorder, characterized by a typical clinical triad: purpura, weakness, and arthralgias, with visceral complications such as liver and renal involvement. The objective was to study the association between hepatitis C virus (HCV) infection and essential mixed cryoglobulinemia (EMC).

PATIENTS AND METHODS

Markers of HCV infection in 11 patients with cryoglobulinemia were examined and hepatitis C virus (HCV) was detected in eight of them. These patients were included in a clinical and histologic study. Anti-HCV antibodies were determined by a second-generation enzyme-linked immunosorbent assay (ELISA-2) in sera and cryoprecipitates. Studies on HCV-RNA were performed by a two-stage polymerase chain reaction (PCR) in the serum. A control group, consisting of 28 patients with other cutaneous disorders, was studied for HCV infection using ELISA-2 and PCR.

RESULTS

All patients had liver dysfunction, arthralgias, and purpura. Three patients had involvement of the peripheral nervous system, two had renal involvement, and one patient had Sjögren's syndrome. Cryocrits ranged from 3% to 20%. Six patients had type III cryoglobulinemia and the remaining two had type II. Markers for hepatitis B virus (HBV) were negative in all serum samples. Anti-HCV antibodies and HCV-RNA were positive in the serum of all the cases with MC. Anti-HCV antibodies were positive in all cases except for one of the cryoprecipitates tested. Four patients received recombinant interferon alfa. In two of them, serum aminotransferases became normal and cryoglobulins disappeared.

CONCLUSIONS

The results strongly suggest that HCV infection is responsible for the cryoglobulinemia and vasculitis in patients with MC and that treatment with interferon alfa is presently the treatment of choice for such patients.

Thrombocytopenia associated with hepatitis C viral infection

BACKGROUND/AIMS

We investigated whether chronic hepatitis C infection is associated with thrombocytopenia.

METHODS/RESULTS

Thrombocytopenia (<15 x 10(4) platelets/mu l) was diagnosed in 151 of 368 patients (41.0%) with chronic hepatitis C, a significantly higher proportion than that observed in patients with chronic hepatitis B (18.9%, p < 0.01). Elevated titers of platelet-associated immunoglobulin G were observed in 88.1% of patients with chronic hepatitis C and in 47.1% of patients with chronic hepatitis B. Platelet-associated immunoglobulin G titers were significantly higher in patients with chronic hepatitis C (87.3 +/- 10.1 ng/10(7) cells) vs. those with chronic hepatitis B (30.3 +/- 6.4) or the control subjects (p < 0.01). There was a significant negative correlation between platelet-associated immunoglobulin G titers and platelet counts in both chronic hepatitis C and B cases. Platelet-associated immunoglobulin G titers were significantly higher in patients with type C cirrhosis than in those with type B cirrhosis. Interestingly, HCV-RNA was detected by RT-PCR in the platelets from 11 of 14 patients with hepatitis C virus.

CONCLUSIONS

These data indicate that chronic infection with hepatitis C virus may produce a significant autoimmune reaction to platelets, leading to thrombocytopenia.

Mixed cryoglobulinemia secondary to hepatitis C virus infection

Mixed cryoglobulinemia is a systemic vasculitis with clinical manifestations ranging from the characteristic benign-appearing syndrome of palpable purpura, arthrologies, and fatigue to severe vasculitis involving vital organs. A strong association of the disease with hepatitis C virus infection and the demonstration of the specific concentration of the virus in the cryoglobulins have implicated hepatitis C virus in the etiopathogenesis of the disease. The increase in illicit intravenous drug use in the past 30 years seems to have raised the occurrence in the United States of this once uncommon disease and changed the demographics: there seem to be more male intravenous drug users in their forties with the disease than women without risk factors for hepatitis C virus infection in their fifties and sixties. Pathogenesis, therapy, and the hypothesis on the etiologic role of hepatitis C virus are reviewed, and the implications of recent studies and new concepts for treatment of this often benign-appearing but deceptive and potentially life-threatening disease are discussed.

Dilated cardiomyopathy associated with hepatitis C virus infection

BACKGROUND

Myocarditis is thought to be commonly caused by various viruses, and accumulating evidence links viral myocarditis with the eventual development of dilated cardiomyopathy. In many cases, however, the evidence is only circumstantial, and direct conclusive proof is not available. Polymerase chain reaction (PCR) has been used to detect enterovirus RNA in myocardial tissue, but the wide discrepancy in results emphasizes the need for further study.

METHODS AND RESULTS

We investigated hepatitis C virus infection in patients with dilated cardiomyopathy. The presence, type, and quantity of hepatitis C virus RNA were evaluated in the sera, and the presence of positive and negative strands of hepatitis C virus RNA in the heart was investigated with the PCR technique. Anti-hepatitis C virus antibody was present in the sera of 6 of 36 patients (16.7%) with dilated cardiomyopathy and in 1 of 40 patients (2.5%) with ischemic heart disease, showing a statistically significant (P < .05) difference. At an earlier time, acute myocarditis was suspected in 3 patients who had developed acute onset of heart failure, and the diagnosis was confirmed by endomyocardial biopsy in 1 patient. Hepatitis C virus RNA was present in the sera of 4 of the 6 patients, and all 4 had hepatitis C virus type II. The copy number of hepatitis C virus RNA in the serum was 8 x 10(2) to 2 x 10(3) genomes per 1 mL serum. Positive strands of hepatitis C virus were found in the hearts of 3 patients, and negative strands of hepatitis C virus were detected in the heart of 1 patient.

CONCLUSIONS

The results suggest that hepatitis C virus infection is frequently found in patients with dilated cardiomyopathy and that hepatitis C virus is an important causal agent in the pathogenesis of the disease. Antiviral therapy against hepatitis C virus may be indicated in these patients.

Hepatitis C virus infection of mononuclear cells from peripheral blood and liver infiltrates in chronically infected patients

The mechanisms underlying chronicity of hepatitis C virus (HCV) infection are poorly understood, but the importance of impaired viral clearance by the immune system has been suggested. The prevalence of HCV infection of peripheral blood mononuclear cells (PBMC) was in investigated in 34 persistently infected patients with anti-HCV (7 with liver cirrhosis, 10 with chronic active hepatitis, 5 with chronic persistent hepatitis, 4 with chronic lobular hepatitis, and 8 healthy carriers) by polymerase chain reaction (PCR). HCV infection of 116 T cell clones derived from liver infiltrating mononuclear cells obtained from 3 patients with chronic liver disease was examined using the same methods. HCV genomic sequences were found in fresh, unstimulated PBMC from 20 patients with cirrhosis, and chronic active and persistent hepatitis, but in none of the healthy carriers and only in mitogen-activated cells from 1 out of 4 patients with autoresolving chronic lobular hepatitis. Active PBMC infection was confirmed by identification of anti-genomic HCV sequences in the majority of HCV RNA-positive cells (fresh or mitogen-stimulated). A high percentage of T cell clones obtained from liver infiltrates were found to be infected by HCV. These findings suggest that HCV infection of lymphatic cells plays a role in the pathogenesis of chronically evolving liver damage. PBMC may represent a reservoir for latent infection and a site for viral multiplication.

The association of complement activation at a low temperature with hepatitis C virus infection in comparison with cryoglobulin

Complement activation at a low temperature in vitro and cryoglobulinaemia are associated with hepatitis C virus (HCV) infection. The frequency of HCV antibody positivity determined in serum specimens that showed the cold-dependent activation of complement was 100%, whereas it was 48% among sera with cryoglobulin. On the other hand, the frequency of cold activation among HCV-infected sera was 41%, and that of cryoglobulin 48%. Cold activation was not found in any HCV- sera studied, whereas cryoglobulin was found at a frequency of 14% in HCV- sera. Cold activation was also absent among hepatitis B virus (HBV) S antigen or antibody-positive sera, except a few that were both HBV+ and HCV+. Rheumatoid factor was also frequently detected in sera with cold activation or cryoglobulin. Cold activation and cryoglobulin may be generated by common mechanisms in which a low avidity, low temperature-preferring antibody may function. In sera with cold activation, fine particles of immune complexes, which do not form precipitates, may activate the complement system. HCV is a unique virus that coexists with antibody in the serum, therefore the avidity of the antibody for the virus antigen may be low, and occasionally react only at a low temperature. This may be why the in vitro phenomenon related to immune complexes occurs specifically in HCV-infected sera.

Clinical and virological findings in mixed cryoglobulinaemia

OBJECTIVES

As a close relationship has been established between mixed cryoglobulinaemia and hepatitis C virus (HCV) infection, the clinical, histological and virological findings of patients affected by mixed cryoglobulinaemia were determined.

DESIGN

Hepatitis C virus infection was investigated by the presence of anti-HCV antibodies and PCR amplification of the 5' untranslated region (5' UTR), and the genotype of HCV was also determined according to Okamoto. A bone marrow biopsy was performed in all patients and liver and kidney biopsies when indicated.

SUBJECTS

Eighty-two subjects affected by mixed cryoglobulinaemia were enrolled in this study.

RESULTS

The prevalence of anti-HCV antibodies was high (83%); PCR amplification of the 5'UTR region was performed in 52 subjects and in 44 of them (85%) the results were positive. In the same subjects, the Core region amplification was positive in 46 cases (88%). A high prevalence of genotype II was found (54%). Chronic liver disease was present in 55 patients (67%). Bone marrow biopsies showed the presence of low-grade non-Hodgkin's lymphomas in 11 cases (13%). Membrano-proliferative glomerulonephritis was found in seven subjects (8%).

CONCLUSIONS

Mixed cryoglobulinaemia is associated with HCV infection in the nearly all cases. Several HCV genotypes are involved in the pathogenesis of this disease. Mixed cryoglobulinaemia is associated with a high prevalence of chronic liver disease, low-grade non-Hodgkin's lymphomas and membrano-proliferative glomerulonephritis.

Clonal B-cell expansions in peripheral blood of HCV-infected patients

Clonal expansions of IgM-producing B cells were investigated in 38 patients with a chronic hepatitis C virus infection. Eight patients were affected with type II mixed cryoglobulinaemia (two of whom also had non-Hodgkin's lymphoma and one had Waldenström's disease), one with type III mixed cryoglobulinaemia, one with Waldenström's disease, and 28 with chronic liver disease. To detect the clonal B-cell expansions we used a RT/PCR procedure in which the CDR3/FW4 regions of the IgM heavy chain mRNAs were amplified and resolved in sequencing polyacrylamide gels. Clonal Ig gene rearrangements were detected in all patients with type II mixed cryoglobulinaemia and also at a high frequency (24%) in the HCV-infected patients without cryoglobulinaemia. A polyclonal pattern was present in the patient with type III mixed cryoglobulinaemia and in the 15 normal individuals and 16 age-related patients with HCV-negative alcoholic liver disease which were investigated as controls. No association was found between the presence of a clonal B-cell expansion and age, sex, liver histology, or levels of serum aminotransferase. The serum levels of rheumatoid factor were increased in all patients with a clonal expansion, suggesting that the expanded B-cell clones belong to the rheumatoid factor producing B-cell subset.

Successful cyclophosphamide treatment of cryoglobulinemic membranoproliferative glomerulonephritis associated with hepatitis C virus infection

A 54-year-old man with cryoglobulinemia and chronic hepatitis C infection presented with progressive renal insufficiency caused by membranoproliferative glomerulonephritis. Because of a steady decline in renal function, cyclophosphamide therapy was instituted. Within 1 month of starting therapy, his cryoglobulins disappeared, and in 3 months, his creatinine clearance had improved from 56 mL/min to 89 mL/min. At no point in his course was there clinical evidence of liver disease. After 1 year, cyclophosphamide was successfully stopped. Fourteen months later, his creatinine clearance is 105 mL/min. These results suggest that cyclophosphamide may be useful therapy for patients with cryoglobulinemic membranoproliferative glomerulonephritis and hepatitis C virus infection who have progressive renal insufficiency.

Cryoglobulinemia: a cause for false negative polymerase chain reaction results in patients with hepatitis C virus positive chronic liver disease

With the introduction of interferon therapy for liver disease due to chronic viral hepatitis, it has become important to test individuals thought to have hepatitis C virus disease for the presence of the virus. Moreover, the current goal of therapy for hepatitis C virus-positive liver disease is to render the individual patient HCV-RNA negative. Recently, it has been reported that as many as one-third of the patients with hepatitis C virus liver disease test positive for the presence of mixed cryoglobulins. Few of these cryoglobulin-positive patients have overt disease manifestations of cryoglobulinemia, such as nephropathy, peripheral neuropathy and vasculitis. Because the cryoglobulins in patients with hepatitis C virus-positive disease are directed at hepatitis C virus epitopes, the precipitation of cryoglobulins from serum samples also effectively removes virus. When the viral carriage rate is low in terms of the number of genomes/unit serum, as occurs in cases that are partially treated, the serum can test negative for hepatitis C virus even by polymerase chain reaction, despite the presence of persistent viremia, if precautions preventing the precipitation of cryoglobulins prior to the removal of the sample for polymerase chain reaction testing are taken. From a group of 75 patients with hepatitis C virus-positive hepatitis seen at our institution in the last year (all HCV-RNA positive), 35% were found to test positive for the presence of cryoglobulins. Importantly, in all cases, the cryoglobulins collected tested strongly positive for HCV-RNA.(ABSTRACT TRUNCATED AT 250 WORDS)

Hepatitis C virus associated cryoglobulinemic neuropathy successfully treated with plasma exchange

A 28-year-old Japanese woman who suffered from mononeuritis multiplex was admitted to our hospital. Serological study revealed cryoglobulinemia (type III), hypocomplementemia, high titers of rheumatoid factor (RF), and positive antihepatitis C virus (HCV) antibody. Nerve conduction velocities were slower in sensory nerves than in motor nerves. Biopsied sural nerve showed a marked decrease of myelinated fibers but no evidence of angitis. She received plasma exchange and cryoglobulinpheresis over a period of 2 months with approximately 2.0 L (40 ml/kg) of plasma replaced in each procedure. Both plasma exchange and cryoglobulinpheresis alleviated clinical symptoms, and nerve conduction velocities were improved in several nerves. The serum cryoglobulin level was markedly reduced after the treatment together with the recovery of the C4 level. Thus, complements appeared to be consumed in large quantities in the presence of cryoglobulinemia in this patient. Efficacy of cryoglobulinpheresis indicates the possibility that cryoglobulins produced in association with HCV infection played a role in damaging the nerve directly through the activation of the complement system.

High prevalence of hepatitis C infection in Afro-Caribbean patients with type 2 diabetes and abnormal liver function tests

Moderate elevations of serum transaminases are frequently found in patients with diabetes mellitus and are often attributed to fatty infiltration of the liver without further investigation. Recent studies of patients with end-stage liver disease have suggested a possible association between Hepatitis C virus (HCV) antibody positivity and the development of diabetes (mostly Type 2). As a first step in the examination of any potential association between HCV and Type 2 diabetes in subjects without overt liver disease, we examined 200 British patients with Type 2 diabetes (100 White Caucasians, 50 Asians, and 50 Afro-Caribbeans), recruited from the United Kingdom Prospective Study of Diabetes, half of whom had a significant elevation of alanine aminotransferase (ALT) on at least two occasions and half of whom had consistently normal ALT levels. In Afro-Caribbean Type 2 diabetic subjects 7/25 (28%) patients with abnormal ALT and 1/25 (4%) with normal ALT were HCV antibody positive. Among White Caucasian subjects 6/50 (12%) patients with abnormal LFTs and 0/50 with normal LFTs were HCV antibody positive and in Asians the prevalence was 2/25 (8%) and 0/25, respectively. This study suggests that persistent mild to moderate elevation of serum transaminases in a patient with Type 2 diabetes should not automatically be attributed to the metabolic disturbances of diabetes. Particularly in Afro-Caribbean subjects, HCV infection is a major diagnostic consideration. The question of whether HCV infection itself may have a diabetogenic action is worthy of further investigation.

Quantitation of hepatitis C virus genome molecules in plasma samples

A competitive reverse transcription PCR (cRT-PCR)-based assay for the quantitative detection of hepatitis C virus (HCV) viremia was developed, optimized, and applied to the direct molecular analysis of clinical samples from nine patients with persistent HCV infection. As for other competitive PCR-based applications, this method consists of the reverse transcription and subsequent amplification of two RNA species in the same tube: the wild-type template (to be quantified) and a known amount of a modified synthetic template. These templates have identical primer recognition sites and very similar (but not identical) sizes, thus allowing direct detection of both template species after gel electrophoresis and ethidium bromide staining. The results obtained by this cRT-PCR application for testing clinical samples from HCV-infected patients mainly indicate that the competitive approach reaches the degree of sensitivity (fewer than 5 HCV RNA molecules per 100 microliters) necessary to evaluate viral load in all HCV-infected patients, independently of clinical conditions, and that this technique is flexible enough to quantify highly divergent levels of cell-free HCV genome copy numbers in biological samples. Interestingly, we observed a sample-to-sample variation in the loss of detectable HCV genome molecules in serum in comparison with that in plasma from the same patient, thus indicating that serum specimens, although widely used in the past few years for qualitative molecular investigation of HCV-infected patients, cannot be used to obtain reliable quantitative data on HCV viremia from these patients.

Two-dimensional polyacrylamide gel electrophoresis analysis of cryoglobulins and identification of an IgM-associated peptide

The clonality of immunoglobulins (Igs) in cryoprecipitates (n = 41) was studied by two-dimensional polyacrylamide gel electrophoresis (2-D PAGE). Our series included 24 cryoglobulins characterized by immunofixation electrophoresis (IF), 12 'trace amount' cryoglobulins, defined by a protein content in the precipitate of less than 0.05 mg/ml of serum, and five cryoglobulins of undetermined protein composition by IF. 2-D PAGE analysis showed polyclonal IgG associated either with monoclonal Igs (type II cryoglobulins; n = 14) or with polyclonal IgM (type III cryoglobulins; n = 14). In ten cryoprecipitates (two 'trace amount' cryoglobulins as well as seven of 19 type II and as one of five type III cryoglobulins by IF) polyclonal IgG were associated with a mixture of polyclonal and monoclonal IgM. These cryoglobulins were tentatively named type II-III cryoglobulins. A monoclonal IgM was observed in one cryoprecipitate (type I cryoglobulins). Two cryoglobulins presented unexpected 2-D patterns, characterized by the presence of oligoclonal IgM, with trace amounts of Igs of different isotypes (tentatively named type II-III(variant) cryoglobulins). A peptide of 44 kDa with a pI of 5.45 was observed in all cryoglobulins containing IgM (n = 40). This peptide was also present in purified monoclonal or polyclonal IgM fractions. N-terminal microsequencing (12 amino acid residues) revealed that this IgM-associated peptide was an unknown protein. Our results highlight the role of 2-D PAGE as an aid in the analysis of cryoglobulins.

Pathology of hepatitis C

The basic morphological patterns of acute or chronic viral hepatitides are very similar, irrespective of the causative hepatitis viruses A, B, C, D or E. In addition, however, acute and chronic hepatitis C shows characteristic, although not pathognomonic histological changes. These consist of lymphoid aggregates in portal tracts, sometimes with germinal centers, damage of bile duct epithelium, and micro- or macrovesicular steatosis of hepatocytes. A combination of two of these three characteristic alterations is seen in over half of the patients with chronic hepatitis C and is helpful in the histological diagnosis of the disease.

Hepatitis C virus chronic infection as a common cause of mixed cryoglobulinaemia and autoimmune liver disease

OBJECTIVES

Mixed cryoglobulinaemia (MC) and autoimmune chronic hepatitis (AI-CH) are frequently associated with hepatitis C virus (HCV) chronic infection. Because HCV represents a possible common aetiological factor, the aim of the present study is to investigate the clinico-serological alterations of both MC and AI-CH and to verify a possible overlap between these disorders.

SETTING

Patients from three tertiary referral centres.

SUBJECTS

Two Italian series of 88 MC patients and 30 AI-CH type 1 were studied.

RESULTS

MC and AI-CH share several clinico-serological features. The patients' mean age (MC vs. AI-CH: 60 +/- 9 vs. 57 +/- 13 years), disease duration (10.5 +/- 5 vs. 9.6 +/- 6 years), and female/male ratio (3.4 vs. 3.3) were very similar in the two series. Typical hallmarks of MC, i.e. purpura, arthralgias, and weakness, circulating mixed cryoglobulins with rheumatoid factor activity, and hypocomplementemia were also recorded in a significant number of AI-CH patients. Similarly, chronic active hepatitis was found in 68% of MC patients and its histological and serological alterations were comparable with those of AI-CH; moreover, amongst various autoantibodies, antinuclear antibodies and/or anti-smooth-muscle antibodies were detected in half of the cases of MC. Anti-HCV antibodies, detected by second-generation Chiron ELISA and RIBA, were present in a high percentage of both MC and AI-CH (94 vs. 80%), and frequently associated with HCV viraemia (86 vs. 77%). Finally, anti-GOR, the HCV-related autoantibodies, were found in half cases of MC and AI-CH.

CONCLUSIONS

On the whole, these data suggest that HCV in combination with other infectious and environmental and genetic factors can trigger a complex immunological disorder with different clinical patterns.

Active hepatitis C virus infection in bone marrow and peripheral blood mononuclear cells from patients with mixed cryoglobulinaemia

The presence of hepatitis C virus (HCV) genomic sequences was checked in plasma, liver, peripheral blood mononuclear cells (PBMC) and bone marrow cells from 11 patients with mixed cryoglobulinaemia positive for anti-HCV antibodies, and from 11 patients with chronic HCV hepatitis without serological evidence of cryoglobulinaemia. HCV RNA sequences were demonstrated by reverse transcription polymerase chain reaction in seven plasma samples, in six PBMC samples, and in seven bone marrow cell samples from the 11 cryoglobulinaemic subjects; otherwise, viral specific nucleic acids were detected in 10 plasma samples, in one PBMC sample, and in two bone marrow cell samples from the 11 patients with chronic hepatitis. The HCV replicative intermediate was evidenced in four of the six PBMC and in five of the seven bone marrow aspirate HCV RNA-positive samples. Analysis of subpopulations isolated from bone marrow and peripheral blood samples showed HCV RNA sequences in mononuclear cells belonging either the CD2+ subset or to the CD19+ subpopulation or to the adherent cells. Finally, we compared the nucleotide sequences of a large portion (-270 to -59) of the HCV 5'-untranslated region from five patients with mixed cryoglobulinaemia and from seven patients with chronic hepatitis without cryoglobulinaemia; the degree of heterogeneity, compared with the prototype HCV sequence, was similar in both groups. These findings from two groups of HCV-infected patients indicate that transient or permanent active HCV infection of bone marrow and PBMC is frequent in anti-HCV-positive patients with mixed cryoglobulinaemia, and suggest that extra-hepatic infection may play a major role in influencing the pathophysiology of this infection as well as the viral persistence.

Cryoglobulinemia in chronic liver diseases: role of hepatitis C virus and liver damage

BACKGROUND/AIMS

Mixed cryoglobulinemia is frequently associated with liver diseases. The respective role of hepatitis C virus (HCV) and liver damage in the pathogenesis of cryoglobulinemia is investigated in this study.

METHODS

The prevalence of cryoglobulinemia in 226 consecutive patients with chronic liver diseases (hepatitis C, 127; hepatitis B, 40; other diseases, 59) was studied, and the epidemiological, biological, histological, and virological features in these three groups were analyzed. Anti-HCV antibodies, HCV proteins, and HCV RNA were searched in the cryoprecipitates.

RESULTS

The prevalence of mixed cryoglobulinemia was high (41.5%) in patients with liver diseases and higher in patients with hepatitis C (54.3%) than in patients with hepatitis B (15%) or other causes of liver disease (32%). Patients with cryoglobulinemia had cirrhosis more frequently and had a longer history of hepatitis. In patients with hepatitis C, HCV RNA sequences and HCV proteins were detected in the cryoprecipitate. Cryoglobulins became undetectable in 21 of 43 patients treated with interferon.

CONCLUSIONS

These findings suggest that HCV is a major cause of cryoglobulinemia. Besides viral infection itself, multiple factors appear to be responsible for the production of cryoglobulins, including cirrhosis and duration of liver disease.

Interferon alfa-2a therapy in cryoglobulinemia associated with hepatitis C virus

BACKGROUND

Essential mixed cryoglobulinemia is frequently associated with hepatitis C virus (HCV) infection. A beneficial effect of interferon alfa therapy has been reported, but we do not know whether the antiviral activity of the drug affects the clinical and biochemical manifestations of disease.

METHODS

In a prospective randomized, controlled trial, we studied 53 patients with HCV-associated type II cryoglobulinemia. A group of 27 patients received recombinant interferon alfa-2a thrice weekly at a dose of 1.5 million units for a week and then 3 million units thrice weekly for the following 23 weeks. The 26 control patients did not receive anything apart from previously prescribed treatments. All patients were then followed for an additional 24 to 48 weeks.

RESULTS

Interferon was usually well tolerated, but it was permanently discontinued in two patients because of atrial fibrillation and depression. Two of the 26 patients in the control group were lost to follow-up. After the treatment period, serum HCV RNA was undetectable in 15 of the remaining 25 patients who received interferon alfa-2a, but in none of the controls. In comparison with the control group, the 15 patients with undetectable levels of HCV RNA in serum had significant improvement in cutaneous vasculitis (P = 0.04) and significant decreases in serum levels of anti-HCV-antibody activity (P = 0.007), cryoglobulins (P = 0.002), IgM (P = 0.002), rheumatoid factor (P = 0.001), and creatinine (P = 0.006). After treatment with interferon alfa-2a was discontinued, viremia and cryoglobulinemia recurred in all 15 HCV RNA-negative patients. On resumption of treatment, three of four patients had a virologic, clinical, and biochemical response.

CONCLUSIONS

The therapeutic efficacy of interferon alfa-2a in HCV-associated cryoglobulinemia is closely related to its antiviral activity, thus supporting the idea that HCV infection may be a cause of this disease.

Presence of hepatitis C virus (HCV) genomic RNA and viral replicative intermediates in bone marrow and peripheral blood mononuclear cells from HCV-infected patients

The cellular tropism of hepatitis C virus (HCV) was studied in vivo in samples from patients with persistent HCV infection. Plasma, liver, peripheral blood mononuclear cell (PBMC), and bone marrow cell (BMC) samples from 15 subjects positive for anti-HCV antibodies were tested for the presence of HCV RNA sequences by reverse transcription PCR. Virus-specific RNA sequences were found to be present in liver samples from all subjects (100%), in plasma samples from 13 of 15 patients (86.7%), in PBMC samples from 3 patients (20%), and in BMC samples from 9 (60%) of the 15 anti-HCV-positive patients enrolled in this study. The presence of the molecular intermediate of HCV replication (the negative-stranded HCV RNA) was evident in the two of the three PBMC and in five of the nine BMC HCV RNA-positive samples. Finally, we studied the nucleotide sequence of a large portion (-270 to -59) of the 5'untranslated region of HCV amplified from plasma samples of 12 of the 15 patients with and without HCV in BMCs; the degree of heterogeneity compared with the prototype HCV sequence was similar in both groups. The data principally indicate that HCV infection of PBMCs and BMCs is frequent in persistently infected patients, as shown by the occurrence of positive- and negative-stranded HCV RNA, thus suggesting the possibility of extrahepatic replication of HCV.

Long-term results of therapy with interferon alpha for cryoglobulinemia associated with hepatitis C virus infection

We describe the long term results of treatment with interferon (IFN) in two patients with cryoglobulinemia and chronic hepatitis related to Hepatitis C virus (HCV). Our results suggest that interferon may induce long remission in cryoglobulinemia associated with HCV infection and that the effect of IFN is not dependent on the effect on liver function, but results of its antiviral activity.

Mixed cryoglobulinemia and hepatitis C virus

BACKGROUND

Mixed cryoglobulinemia (MC) is frequently associated with clinical and biological evidence of liver disease and has recently been reported in cases of hepatitis C virus (HCV) infection. The aim of this study was to assess prospectively in a large series of MC patients: (1) the prevalence of HCV markers (anti-HCV antibodies and HCV RNA in serum and cryoprecipitate); (2) the main clinical, biologic and liver histologic features in patients with or without HCV infection.

PATIENTS

One hundred fifteen consecutive unselected MC patients were studied: 45% had well-defined underlying diseases ("nonessential" MC). Fifty-five percent with no cause of MC were considered to have "essential" MC and were subjected to in-depth examination.

METHODS

Patients were considered to have MC if two successive determinations of their serum cryoglobulin level were above 0.05 g/L. Anti-HCV antibodies (Ab) were detected in all patients by second-generation tests (ELISA, RIBA). We also looked for HCV RNA sequences amplified by polymerase chain reaction (PCR) in the sera and cryoprecipitates of 39 patients; HBs antigen, anti-HBs Ab and anti-HBc Ab in all patients; and HBV DNA in 20 sera and 17 cryoprecipitates. Quantitative HCV Ab and RNA studies were performed on whole serum, cryoprecipitates, and supernatants. Clinical features were recorded retrospectively for each patient. Liver biopsies from 23 anti-HCV Ab-positive and 7 anti-HCV Ab-negative patients were examined histologically, with qualitative and quantitative analysis.

RESULTS

Anti-HCV Ab were found in 47/115 (41%) patients by ELISA and RIBA: 33/63 (52%) essential MC and 14/52 (27%) nonessential MC. Among the 63 essential MC patients, the 33 anti-HCV Ab-positive (Group 1) were compared to the 30 anti-HCV Ab-negative patients (Group 2). Group 1 patients had more cutaneous involvement (Raynaud's phenomenon, purpura, livedo, distal ulcers, or gangrenous changes) (17 versus 5: p = 0.004), higher alanine aminotransferase levels (110 +/- 22 versus 41 +/- 10 IU; p < 0.005), higher serum cryoglobulin levels (0.35 +/- 0.07 versus 0.12 +/- 0.04 g/L; p = 0.01), lower CH50 (28 +/- 3 versus 44 +/- 2 CH50/mL; p = 0.0001) and lower C4 levels (0.20 +/- 0.02 versus 0.29 +/- 0.03 g/L; p < 0.04). The prevalence of HBV serum markers was low in both groups, and HBV DNA was never detected in any of the sera and cryoprecipitates tested. HCV RNA sequences were detected in 10/16 (63%) sera and 12/16 (75%) cryoprecipitates from Group 1 patients, whereas they were not in the sera or cryoprecipitates from 23 Group 2 patients. Using quantitative PCR, HCV RNA in cryoprecipitates was concentrated 20 to 100 times despite the absence of significant anti-HCV Ab concentration in these samples. Histologic examination of liver biopsies revealed a spectrum of lesions ranging from chronic active hepatitis to cirrhosis, but Knodell's score did not differ between the groups.

CONCLUSION

(1) About 50% of the essential MC patients had anti-HCV Ab, and these patients had more severe cryoglobulinemia-associated clinical and biological signs; (2) HCV RNA sequences were found in the large majority of sera and cryoprecipitates from patients with essential MC and anti-HCV Ab and were more concentrated in cryoprecipitates than in supernatants. These results suggest a role for HCV in the pathogenesis of MC and indicate that many cases of essential MC may be secondary to HCV infection and thus nonessential.

Hepatitis C virus infection and mixed cryoglobulinemia: a striking association

The high frequency of liver involvement in cryoglobulinemia is well established. Although both etiology and pathogenesis have remained so far undefined, recent studies suggest an association of mixed cryoglobulinemia with hepatitis C virus infection. To explore this hypothesis further, we assessed the prevalence of hepatitis C virus antibodies and RNA in a large group of patients, including: (1) 35 patients with cryoglobulinemia without clinical evidence of liver involvement (group 1), (2) 15 patients with symptomatic cryoglobulinemia associated with chronic liver disease (group 2) and (3) 12 patients with asymptomatic cryoglobulinemia associated with chronic liver disease (group 3). Anti-hepatitis C virus antibodies were detected by a second-generation enzyme-linked immunosorbent assay and third-generation immunoblot (SIA Prototype RIBA), whereas the polymerase chain reaction was used for the detection of viral RNA. Anti-hepatitis C virus antibodies, as detected by enzyme-linked immunosorbent assay, were demonstrated in 21 (60%) patients from group 1, 11 (73.3%) from group 2 and 10 (83.3%) from group 3. The immunoblot identified as positive 3 further patients in group 1 (giving a prevalence of 68.6%) and all patients in groups 2 and 3. Hepatitis C virus RNA was demonstrated in cryoprecipitates from 21 of 24 immunoblot-positives and from 6 of 11 immunoblot-negatives, indicating an actual active viral replication in 77.1% of group 1. This was also found in 13 (86.7%) and 10 (83.3%) cryoprecipitates of groups 2 and 3, respectively. Type II cryoglobulinemia was the prevalent form in group 1 (88.6%) and group 2 (73.3%), whereas type III was found in group 3 (58.3%) and in 26.7% of group 2.(ABSTRACT TRUNCATED AT 250 WORDS)

IgM and IgG antibodies to hepatitis C virus in patients with mixed cryoglobulinaemia

To assess the relationship between hepatitis C virus (HCV) infection and essential mixed cryoglobulinaemia (EMC), sera from 23 patients with EMC were tested for IgG and IgM antibodies to HCV antigens and for HCV RNA. Quantitative HCV antibody studies were performed on serum and purified cryoglobulin fractions. HCV antibodies of both IgG and IgM class were found in 22 (96%) patients. Ten of these were also HCV-RNA positives. Higher titres of anti-HCV IgM were present in the 11 patients with evidence of liver damage. Anti-HCV IgG antibodies were shown to be concentrated in the IgG fraction of cryoglobulins in all eight patients studied. These results strongly suggest a role for HCV in the pathogenesis of EMC.

The association between hepatitis C virus infection and in vitro activation of the complement system

The phenomenon of in vitro activation of the classical complement pathway at low temperatures (4-21 degrees C) is known as cold activation, and has been suggested to be associated with non-A, non-B hepatitis. We re-examined the association by using newly developed markers of hepatitis C virus (HCV) infection. Twenty-one cases randomly selected from those fulfilling the screening criteria of complement cold activation all showed evidence of HCV infection. More than half of 55 HCV antibody-positive cases selected randomly from our laboratory samples showed a tendency towards cold activation, whereas none of the HCV antibody-negative sera showed cold activation. All the HCV antibody-positive cases were negative in cold activation when CH50 was assayed with plasma. These results, taken together, indicate that cold activation of the complement system is strongly associated with HCV infection.

The spectrum of vasculitis in human immunodeficiency virus-infected patients. A clinicopathologic evaluation

OBJECTIVE

To delineate the different types of inflammatory vascular diseases (IVD) occurring in patients with human immunodeficiency virus (HIV) infection.

METHODS

Muscle, nerve, or skin biopsy specimens from 148 symptomatic HIV-infected individuals were reviewed, and subgroups of vasculitis were identified using the American College of Rheumatology (ACR) 1990 clinicopathologic criteria for the classification of vasculitis.

RESULTS

IVD was documented in 34 patients (23%) and included necrotizing arteritis (3 patients), non-necrotizing arteritis (1 patient), neutrophilic IVD (7 patients), mononuclear IVD (17 patients), and other small vessel inflammatory changes (6 patients). According to the ACR criteria, 11 patients could be classified as having a distinct category of vasculitis, including polyarteritis nodosa (4 patients), Henoch-Schönlein purpura (1 patient), and drug-induced hypersensitivity vasculitis (6 patients), and 23 were classified in the group "other vasculitis, type unspecified." One patient had hepatitis B virus surface antigenemia, 2 had cryoglobulinemia, and 2 were coinfected by human T lymphotropic virus type I. Cytomegalovirus inclusions and antigens were found in endothelial cells in 1 patient. HIV antigens and genome were detected in perivascular cells of 2 of the 3 patients with necrotizing arteritis; in 1, HIV-like particles were seen by electron microscopy. Immune deposits were found in small vessel walls in 5 skin biopsy samples showing small vessel vasculitis and in the muscle of the 3 patients with necrotizing arteritis.

CONCLUSION

A wide range of inflammatory vascular diseases may occur in HIV-infected individuals. Vascular inflammation appears multifactorial and may result from HIV-induced immunologic abnormalities and exposure to a variety of xenoantigens, such as HIV itself, other infectious agents, and drugs.

Cryoglobulinemia and cutaneous leukocytoclastic vasculitis associated with hepatitis C virus infection

Hepatitis C virus infection is a frequent cause of non-A, non-B hepatitis worldwide. Resultant morbidity is significant; chronic liver disease develops in 50% of infected persons. Since serologic testing has become available there have been several reports of cutaneous findings in association with hepatitis C virus infection, including vasculitis, cryoglobulinemia, urticaria, and lichen planus. We describe a patient with cryoglobulinemia, chronic cutaneous leukocytoclastic vasculitis, and hepatitis C virus infection. Hepatitis C virus infection should be included in the differential diagnosis of the causes of cryoglobulinemia and leukocytoclastic vasculitis.

Immunologic and viral markers in the circulation of anti-HIV negative heroin addicts

To assess the degree of immune system activation associated with addiction or hepatotropic viruses infection, we examined 60 HIV-negative heroin addicts for the presence of hepatitis B virus (HBV) infection markers, hepatitis C virus antibodies (anti-HCV), various auto-antibodies, and serum levels of soluble interleukin-2 receptors (sIL-2R). In addition, 28 anti-HCV positive patients comprising the disease control group, were also examined. Our results demonstrated a high prevalence of anti-HCV antibodies (61.7% and 90% with 1st and 2nd generation ELISA, respectively). Eighty-seven percent (87%) of the addicts positive for anti-HCV by the latter and 92.8% of the disease control patients, were also positive with 2nd generation recombinant immunoblot assay (RIBA-II). In 88.9% of anti-HCV positive addicts, antibody to C22-3 was the predominant (anti-C33c in 81.5%). Antibodies to C33c and C22-3 polypeptides were also more frequent in disease control group (92.8% and 85.7%, respectively). Anti-HCV antibodies were associated with increased transaminases (ALT or AST, P < 0.05), as well as with longer duration of addiction (P < 0.005). HBV infection markers (HBsAg, anti-HBc only and anti-HBs) were also present in the addicts (5%, 28.3% and 26.7%, respectively). Rheumatoid factors (RF) were detected in 36.7%, antinuclear antibodies (ANA) in 11.7%, antibodies (IgG and/or IgM) against cardiolipin (anti-CL) and double stranded DNA (anti-ds DNA) in 20% and 50%, respectively. RF, ANA, anti-CL and anti-dsDNA antibodies were also detected in the disease control group (32.1%, 89.3%, 28.5% and 28.5% respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of alpha-interferon on hepatitis C virus chronic infection in mixed cryoglobulinemia patients

Since a striking association between hepatitis C virus (HCV) infection and mixed cryoglobulinemia has been demonstrated, the aim of this study is to investigate the effect of alpha-interferon (alpha-IFN) on HCV viraemia and clinico-serological manifestations of 15 patients (ten female and five male, mean [+/- SD] age 53 +/- 7 years). In 14/15 patients pre-study steroid dosage remained unchanged during treatment. alpha-IFN was administered at a dose of 2 x 10(6) IU daily for a month, then every other day for five months. On the whole, a statistically significant improvement of purpura (p < 0.001), serum transaminases (p < 0.001), and cryocrit (p < 0.01) was observed after alpha-IFN treatment. HCV viraemia was detected by polymerase chain reaction technique in 13/15 patients with mixed cryoglobulinemia and anti-GOR antibodies, expression of HCV-related autoimmunity, were present in 8/15. After alpha-IFN treatment, HCV RNA levels showed a clear-cut reduction in five persons and disappeared in another, while anti-HCV antibodies (Chiron ELISA and RIBA II) did not change after the six-month period of therapy. These data further support the possible etiopathogenetic role of HCV in patients with mixed cryoglobulinemia and suggest that alpha-IFN may be regarded as the elective treatment in this disease.

Membranoproliferative glomerulonephritis associated with hepatitis C virus infection

BACKGROUND AND METHODS

Hepatitis C virus (HCV) infection causes both acute and chronic liver disease and is also associated with mixed cryoglobulinemia. Whether HCV is also associated with renal disease, as is the hepatitis B virus, is not known. We describe the clinical, pathologic, virologic, and immunologic features of eight patients with HCV infection who were referred to nephrologists for glomerulonephritis. Four patients were treated with interferon alfa.

RESULTS

All eight patients had proteinuria, and seven had decreased renal function. Renal biopsy in all patients revealed membranoproliferative glomerulonephritis, characterized by the deposition of IgG, IgM, and C3 in glomeruli. Electron microscopy of the biopsy specimens showed cryoglobulin-like structures in three of four patients. All eight patients had HCV RNA detected in their serum, elevated serum aminotransferase concentrations, and hypocomplementemia, and the majority had cryoglobulins and circulating immune complexes in their serum. Cryoprecipitates from the three patients who were tested contained HCV RNA and IgG anti-HCV antibodies to the nucleocapsid core antigen (HCVc or c22-3). IgM rheumatoid factors, present in all patients, bound anti-HCV IgG in all six patients tested. Four patients received interferon alfa for 2 to 12 months; all had evidence of decreased HCV replication and improvement of their renal and liver disease.

CONCLUSIONS

Chronic HCV infection is associated with cryoglobulinemia and membranoproliferative glomerulonephritis. The pathogenesis is unknown, but may relate to deposition within glomeruli of immune complexes containing HCV, anti-HCV IgG, and IgM rheumatoid factors.

Cryoglobulinemia with vasculitis associated with hepatitis C virus infection

Essential mixed cryoglobulinemia is frequently associated with chronic hepatitis. This report presents four cases of cryoglobulinemia with vasculitis associated with chronic hepatitis related to hepatitis C virus infection. Hepatitis C virus infection was ascertained in the four patients by both the presence in the serum of anti-HCV antibodies detected by the four-antigen recombinant immunoblot assay and of HCV RNA detected by polymerase chain reaction. In two patients tested, anti-HCV antibodies were not detected after centrifugation in the purified cryoglobulin but were detected in the supernatant. HCV RNA was detected in the purified cryoglobulin in all four patients and was detected in the supernatant in three patients. In one patient receiving recombinant interferon alfa, serum aminotransferases normalized and cryoglobulin disappeared; in another patient receiving recombinant interferon alfa, serum aminotransferases remained high and the cryoglobulin persisted. The presence of HCV RNA in the cryoglobulin and the parallelism of the changes of the cryoglobulinemia and of the serum aminotransferases during recombinant interferon alfa administration suggest that HCV infection is responsible for the production of cryoglobulinemia and vasculitis. It is proposed that HCV infection is a cause of cryoglobulinemia associated with chronic hepatitis.

A role for hepatitis C virus infection in type II cryoglobulinemia

BACKGROUND

Type II cryoglobulinemia is a vasculitis characterized by cryoglobulins consisting of complexes of polyclonal IgG and monoclonal IgM rheumatoid factors. The cause of these immune complexes is unknown, though both the hepatitis B (HBV) and C (HCV) viruses have been suspected.

METHODS

We studied 19 patients with Type II cryoglobulinemia for markers of HCV and HBV infection. Quantitative HCV antibody and RNA studies were performed on whole serum, cryoprecipitates, and supernatants.

RESULTS

Eight patients (42 percent) had HCV antibodies, and 16 (84 percent) had HCV RNA: Of the 19 patients, 5 (26 percent) had HBV markers, but only 1 had evidence of active HBV infection. Control serum samples from nine patients with Type I cryoglobulinemia were negative for HCV antibody and HCV RNA: There was a close, although not exclusive, association of one type of rheumatoid factor (WA) with HCV RNA: HCV antibody and HCV RNA were concentrated approximately 10-fold and 1000-fold, respectively, in the Type II cryoglobulins examined.

CONCLUSIONS

Type II cryoglobulinemia is strongly associated with concomitant HCV infection and a high rate of false negative serologic tests. HCV virions and HCV antigen-antibody complexes are concentrated in the cryoprecipitates, most commonly in association with the WA type of rheumatoid factor, suggesting a role for HCV in the pathogenesis of mixed cryoglobulinemia.

Hepatitis C: a possible etiology for cryoglobulinaemia type II

Out of 15 successive patients with mixed essential cryoglobulinaemia type II (monoclonal IgM kappa/IgG), 13 had serological evidence for hepatitis C infection as shown by specific enzyme immunoassays and immunoblot. RNA was purified from the serum of seven patients and hepatitis C sequences were identified in five following reverse transcription and DNA amplification. The liver histology showed chronic active hepatitis with or without cirrhosis in the 12 patients with hepatitis C who had a liver biopsy. The two patients without serological evidence of hepatitis C suffered from haematological malignancies. Hepatitis C may be a major etiological agent of cryoglobulinaemia type II.

Prevalence of anti-HCV and HCV viremia in hemodialysis patients in Taiwan

Hepatitis C viral infection in 125 hemodialysis patients from Taiwan was studied using a second-generation anti-HCV immunoassay (EIA II) (Abbott HCV 2.0 EIA) and the polymerase chain reaction (PCR) to detect the HCV RNA in the serum. A total of 59 patients (47.2%) were positive by EIA II. In comparison, the conventional C100-3 anti-HCV assay was positive in 40 (32.0%). HCV RNA was found in 47 patients (37.6%). Patients with elevated serum transaminase level had a higher positive rate of anti-HCV and HCV RNA. The dialysis time was longer for those patients positive for anti-HCV than for those who were negative. A total of 57 of the 59 EIA II-positive cases had a history of blood transfusion. The HBsAg status did not influence the anti-HCV positivity. Among the 59 EIA II-positive patients, 66.1% were also positive for HCV RNA, and of the 47 HCV RNA-positive cases 83.0% were positive for EIA II. It is concluded that the high prevalence of specific HCV infection and HCV viremia was present in these patients. Prevention of cross-contamination during dialysis and blood screening before transfusion are important for the control of HCV infection in these patients.