Modifications of plasma platelet-activating factor (PAF)-acetylhydrolase/PAF system activity in patients with chronic hepatitis C virus infection

Hepatitis C virus (HCV) chronically infects about 200 million individuals worldwide and leads to severe liver and lymphatic diseases. HCV circulates in the serum, associated with apoB-containing lipoproteins. Platelet-activating factor (PAF), a pro-inflammatory mediator, is mainly modulated by plasma PAF-acetylhydrolase (pPAF-AH), associated with ApoB100-containing low-density lipoproteins (LDL). The aim of the study was to evaluate the potential effects of chronic HCV infection on the PAF/pPAF-AH system. HCV-RNA was detected in plasma, peripheral blood mononuclear cells (PBMC) and liver samples. Plasma PAF levels, pPAF-AH activity, ApoB100 serum titres and pPAF-AH mRNA levels in cultured macrophages were determined. Plasma PAF levels were significantly higher and pPAF-AH activity was significantly lower in HCV patients than in controls. No significant modifications of pPAF-AH mRNA in macrophages or in ApoB100 values were observed in HCV patients compared with controls. Patients who cleared HCV after antiviral treatment showed a complete restoration of pPAF-AH activity and significant decrease of PAF levels during the follow-up. No data exist about the PAF/pPAF-AH system behaviour during HCV infection. This study shows that in HCV patients modifications of pPAF-AH activity/PAF levels take place and that HCV clearance restored pPAF-AH activity. This suggests that circulating viral particles play a role in PAF/pPAF-AH system modifications and such an alteration could be involved in HCV-related damage.

Low serum tryptophan levels, reduced macrophage IDO activity and high frequency of psychopathology in HCV patients

Indoleamine 2,3-dioxygenase (IDO), a key enzyme of tryptophan (TRP) metabolism, is induced in various tissues of patients with bacterial and viral infection or with neoplastic diseases. This induction is considered the main cause of the decreased serum TRP levels, the reduced brain serotonin synthesis and the occurrence of psychopathological disorders often detected in patients with chronic infections or different forms of cancer. We studied 89 subjects including: (a) 39 patients with chronic hepatitis C virus (HCV) infection and mild liver damage (b) 40 healthy controls, and (c) 10 patients with chronic hepatitis B virus (HBV) infection. We measured serum TRP and kynurenine levels and IDO activity in macrophages. Furthermore, each patient had an accurate psychopathological evaluation. HCV-infected patients had lower (-28%) serum TRP concentrations than healthy volunteers or HBV-infected patients with comparable liver damage. Depression and anxiety symptoms were particularly common in HCV patients. Unexpectedly, serum kynurenine levels and IDO activity in cultured macrophages (under both basal or stimulated conditions) were lower in HCV patients than in controls. Our study shows that HCV patients have reduced serum TRP levels and confirms that they frequently suffer from anxiety and depression-related symptoms. The reduced IDO activity found in the macrophages of these patients suggest that HCV infection may hamper macrophage functions.

Prevalence of ANCA in mixed cryoglobulinemia and chronic hepatitis C virus infection

OBJECTIVE

To determine the prevalence, target antigens and clinical associations of antineutrophil cytoplasmic antibodies (ANCA) in chronic hepatitis C without extrahepatic manifestations and in chronic hepatitis C virus (HCV)-associated mixed cryoglobulinemia (MC) in two European centers.

METHODS

50 sera from patients with chronic hepatitis C and 116 sera from HCV-associated MC were tested for cytoplasmic or perinuclear pattern (C-ANCA/P-ANCA) by indirect immunofluorescence test (IFT). ANCA target antigens were determined by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Clinical characteristics of the patients were not different between the two centers. Cryoglobulinemic vasculitis (CV) was biopsy-proven in about 90% of the MC patients. Two patients with HCV-associated MC and 1 patient with chronic hepatitis C had a P-ANCA. A C-ANCA was detected in 1 patient with HCV-associated MC. Eight patients with a HCV-associated MC and 5 patients with chronic hepatitis C had an ANCA either directed against bactericidal/permeability increasing protein (BPI) or cathepsin G (CG). BPI- or CG-ANCA positivity was not associated with a more severe disease course. The C-ANCA titer followed disease activity in one C-ANCA positive HCV-associated MC patient. The subspecificity of the C-ANCA was not determinable in that patient.

CONCLUSION

Two new target antigens of ANCA have been identified in HCV-associated MC and chronic hepatitis C in this study. BPI-ANCA and GC-ANCA were present in about 10% of patients with HCV-associated MC or chronic hepatitis C. ELISA proved to be more sensitive in the detection of ANCA than IFT. The present study on chronic HCV infection adds to various reports on the induction of CG- and BPI-ANCA in chronic infections.

HCV-related cryoglobulinemic vasculitis: an update on its etiopathogenesis and therapeutic strategies

Cryoglobulinemic vasculitis (CV) is an immune-complex-mediated systemic vasculitis involving small-medium sized vessels. A causative role of hepatitis C virus (HCV) in over 4/5 patients has been definitely established on the basis of epidemiological, pathological, and laboratory studies. There is great geographical heterogeneity in the prevalence of CV as well as other HCV-related immuno-lymphoproliferative disorders. Thus, unknown environmental and/or genetic co-factors should contribute to the pathogenesis of these conditions. Due to the biological properties, HCV genomic sequences cannot be integrated into the host genome; the virus could trigger the immunological alterations only indirectly by exerting a chronic stimulus to the immune system. Recent laboratory observations gave us new important insights on the complex pathogenetic mechanism(s) of HCV-related CV. Firstly, the HCV envelop protein E2, able to bind CD81 molecule expressed on B-lymphocytes, might be involved in the first steps of HCV-driven autoimmune and lymphoproliferative phenomena. The interaction between HCV-E2 and CD81 may increase the frequency of VDJ rearrangement in antigen-reactive B-cell. One possible consequence may be the activation of anti-apoptotic Bcl-2 protoncogene that leads to extended B-cell survival. Interestingly, t(14, 18) translocation along with Bcl-2 activation have been demonstrated in B-lymphocytes of 80% HCV-related CV. The B-lymphocyte expansion is responsible for a wide autoantibody and immune-complex production, including mixed cryoglobulins. CV shows a relatively benign clinical course; however, its cumulative survival is significantly worse if compared to general population. For a correct therapeutic approach to HCV-related CV we must deal with conflicting conditions: HCV infection, autoimmune, and lymphoproliferative alterations. Therapeutic strategy of CV includes etiologic, pathogenetic, and/or symptomatic therapies, which should be tailored for the single patient according to the severity of clinical symptoms. A careful clinical monitoring of patients with HCV-related CV is mandatory in all cases, with particular attention to neoplastic complications.

[Hepatitis C virus infection and arthritis. A clinico-serological investigation of arthritis in patients with or without cryoglobulinemic syndrome]

OBJECTIVE

To compare the clinico-serological features of arthritis from two HCV+ patient groups characterized by mixed cryoglobulinemia (MC) or chronic hepatitis (CH).

METHODS

We retrospectively studied 157 MC patients (119 females, mean age 64.8 yrs, range 36-88) and 155 CH patients (103 females, mean age 58.8 yrs, range 30-81). Patients with HBV and/or HIV co-infections and a follow-up shorter than 1 year were excluded. MC was classified according to standard criteria, while CH classification was based on Desmet's criteria.

RESULTS

No differences in epidemiology were demonstrated between the two series of patients. Although significantly prevalent in MC patients, extra-hepatic manifestations including nephropathy, neuropathy, pneumopathy, mixed cryoglobulins, RF positivity and hypocomplementemia were detected in both patient groups. Arthritis was present in 23 CH (15%) and 12 MC (8%) patients. A symmetrical polyarthritis was observed in 87% of 23 CH patients, while cryoglobulinemic arthritis was invariably asymmetrical and pauciarticular. Unlike MC patients, who had a constantly non-erosive arthritis, in 7/23 CH patients arthritis was erosive. Steroids and/or hydroxycloroquine or D-penicillamine were safe and useful in controlling the arthritis over the short-medium time, although clinical response was more evident in MC patients. Instead, in 5/23 CH and 3/12 MC patients, interferon-alpha treatment was able to trigger or exacerbate the arthritis despite a good control of liver function.

CONCLUSIONS

HCV infection seems to be, possibly in genetically predisposed patients, responsible for arthritis at times similar to rheumatoid arthritis. In these patients a careful assessment of the interferon-alpha treatment is mandatory owing to the potential "arthritogenic effect" due to its immunoregulatory properties.

Anti-hepatitis A virus seroprevalence and seroconversion in a cohort of patients with chronic viral hepatitis

BACKGROUND

Patients with chronic hepatitis C infected by hepatitis A virus have a substantial risk of fulminant hepatitis or death, while the course of hepatitis A virus is uncomplicated in most subjects with chronic hepatitis B.

AIM

To evaluate the prevalence of anti-hepatitis A virus antibodies and the incidence of hepatitis A virus seroconversion in a nationwide sample of 530 patients with chronic hepatitis B and/or hepatitis C infection initially susceptible to this infection after a follow-up of some years.

RESULTS

The overall anti-hepatitis A virus prevalence was 85.7%, with no difference between males and females. By the age of 50 years, almost all patients were found to have been exposed to hepatitis A virus. After a mean follow-up period of 76 months the overall anti-hepatitis A virus seroconversion rate in the 76 initially susceptible individuals was 1.2 per 100 person/years. However, it was 0.3 per 100 person/years in those hepatitis B surface antigen positive but 3.36 per 100 person/years in those anti-hepatitis C virus positive. None of the seroconverters was affected by a clinically evident disease or showed deterioration of underlying chronic liver disease.

CONCLUSIONS

The present study shows that Italian patients >50 years of age with chronic liver disease have already been exposed to hepatitis A virus suggesting that anti-hepatitis A virus screening is not advisable in these subjects.

Thyroid cancer in HCV-related mixed cryoglobulinemia patients

OBJECTIVE

The prevalence of thyroid cancer in a series of unselected HCV-related mixed cryoglobulinemic patients was investigated in comparison with a control group.

METHODS

Among 107 consecutive patients with mixed cryoglobulinemia (MC), 94 were eligible for the study. A control group was obtained from a sample of the general population (2,401 subjects), age > 50 years, who had undergone thyroid ultrasonography (582 subjects); 5 sex-matched controls were randomly assigned to each MC patients (470 individuals). The mean age was similar in the MC patients and controls (64.2 +/- 10.0 vs. 63.4 +/- 7.0).

RESULTS

The prevalence of thyroid nodules was higher, although not significantly so, in control subjects than in MC patients (65.3 vs. 54.8%). Two patients with papillary thyroid cancer were found in the MC series, while no case was observed among controls (p = 0.001, chi-square P value; p = 0.02, Fisher's exact test). In both MC patients with papillary thyroid cancer lymphocytic infiltration was observed in the thyroid tissue.

CONCLUSION

The possible association between HCV-related MC and thyroid cancer indicates that a careful monitoring of the thyroid would be opportune during the clinical follow-up of HCV-associated MC patients, especially in those with signs of thyroid autoimmune disorders.

Cryoglobulins

Serum cryoglobulins are found in a wide spectrum of disorders but are often transient and without clinical implications. Monoclonal cryoglobulins are usually associated with haematological disorders, whereas mixed cryoglobulins are found in many infectious and systemic disorders. So called essential mixed cryoglobulinaemia shows a striking association with hepatitis C virus (HCV) infection (> 90%). It is a systemic vasculitis (leucocytoclastic vasculitis) with cutaneous and multiple visceral organ involvement. Chronic HCV infection can lead to a constellation of autoimmune and neoplastic disorders. In this review, the aetiology, diagnosis, disease heterogeneity, and treatment of cryoglobulinaemia are discussed.

T(14;18) translocation in chronic hepatitis C virus infection

Pathogenic mechanisms of B-cell lymphoproliferative disorders in chronic hepatitis C virus (HCV) infection are unclear. We studied t(14;18) translocation by polymerase chain reaction in peripheral blood mononuclear cells from 50 patients with HCV-related liver disease (group A), 7 with mixed cryoglobulinemia syndrome (group B), 55 with HCV-negative liver disease (group C), and 30 with HCV-negative chronic rheumatic disorders or chronic infection by nonhepatotropic agents (group D). T(14;18) was significantly more frequent in group A (13/50 patients = 26 %) and group B (5/7 = 71.4%) patients than in group C (1/55 = 3.6%) and group D (1/30 = 3.3%) ones. Immunoblot analysis showed bcl-2 over-expression in all t(14;18)-positive samples. In group A, 10/13 (77%) patients with t(14;18) and 13/37 (35%) without t(14;18) had serum cryoglobulins in the absence of mixed cryoglobulinemia symptoms (P <.05). These data indicate that t(14;18) and bcl-2 over-expression in lymphoid cells are frequent in chronic HCV infection and suggest that this event may contribute to the pathogenesis of HCV-related lymphoproliferative disorders.

Relation between infection and autoimmunity in mixed cryoglobulinemia

Mixed cryoglobulinemia (MC) is a systemic vasculitis of small to medium-sized vessels due to the vascular deposition of circulating immune-complexes (CIC) and complement. A leukocytoclastic vasculitis is the histologic hallmark of cutaneous manifestations of the disease, while a clonal B lymphocyte expansion in blood, bone marrow, liver, and spleen represents the underlying pathologic alteration responsible for the production of cryo-CIC and non-cryo CIC with rheumatoid factor activity. A causative role of hepatitis C virus (HCV) infection has been demonstrated in the large majority of MC patients. Hepatitis C virus is both a hepatotropic and a lymphotropic virus; due to this latter biological peculiarity, HCV may trigger a constellation of autoimmune-lymphoproliferative disorders. Besides MC, other important HCV-related diseases are porphyria cutanea tarda, autoimmune hepatitis, membranoproliferative glomerulonephritis, and B cell neoplasias. Hepatitis C virus-related MC represents a link between autoimmune and lymphoproliferative disorders; moreover, MC is an important model to study the complex relation between infections and immune system alterations in humans. During the last years many other autoimmune manifestations have been correlated with HCV infection; namely, sicca syndrome, chronic polyarthritis, polydermatomyositis, fibromyalgia, autoimmune thyroiditis, lung fibrosis, and diabetes mellitus. It is often difficult to verify whether the above associations are coincidental or a pathogenetic link actually exists. At least for particular patients' subsets and in some geographic areas, a causative role of HCV seems to be likely. The geographically heterogeneous distribution of HCV-related autoimmune diseases suggests the contribution of important environmental and genetic factors in the pathogenesis of such conditions. In clinical practice, patients with recent-onset, atypical rheumatic and autoimmune disorders should be carefully investigated for possible HCV infection; this is particularly advisable for correct diagnosis and adequate therapeutic strategy.

Hepatitis C virus (HCV) in cryoglobulinaemic leukocytoclastic vasculitis (LCV): could the presence of HCV in skin lesions be related to T CD8+ lymphocytes, HLA-DR and ICAM-1 expression?

An association between mixed cryoglobulinaemia (MC) and hepatotropic viruses, chiefly hepatitis C virus (HCV), has been widely reported. The presence of HCV genomic sequences or HCV-related viral proteins in the serum, purified cryoglobulins, peripheral blood mononuclear cells and into several tissues has suggested an important triggering role for HCV in MC patients. However, only few reports investigated the presence of HCV in cutaneous vasculitis and its potential pathogenetic role. Biopsies of cutaneous purpuric lesions from 5 MC female patients (aged from 40 to 80 years) were carried out for virological and histopathological evaluation. A leukocytoclastic vasculitis pattern was found in 4/5 subjects, while the presence of HCV RNA was detected in 3/5. In only 3 cases biopsy specimens were sufficient for immunohistochemical and direct immunofluorescence (DIF) studies. Immunohistochemical evaluation was performed by means of alkaline phosphatase and monoclonal anti-alkaline phosphatase (APAAP) immune-complexes. In the same skin specimen APAAP and DIF findings were compared with the presence/absence of HCV genomic sequences (PCR technique). In 1 MC patient, the detection of HCV-RNA was associated to a prevalent CD8+ T suppressor pattern with a perivascular and subjunctional distribution as well as an intense expression of second class (HLA-DR) and intercellular adhesion (ICAM-1) molecules on basal keratinocytes, endothelial cells and perivascular infiltrate. These findings suggest a marked inflammatory activation that spreads from endothelial cells to keratinocytes and Langerhans cells. In the 2 HCV-RNA negative specimens the scanty immunopathological staining could indicate a residual activity due to the previous inflammatory event triggered by cryoglobulins. The deposition of circulating HCV-containing immune complexes (CIC) in the skin could be the initial pathogenic event for cryoglobulinemic vasculitis; subsequently CIC could spread from the vascular bed to the perivascular tissue and then could be very rapidly eliminated. If confirmed in larger patients' series these findings could definitely demonstrate a direct role of HCV in the pathogenesis of cryoglobulinemic vasculitis.

Prevalence of mixed infection by different hepatitis C virus genotypes in patients with hepatitis C virus-related chronic liver disease

Multiple infection by different hepatitis C virus (HCV) genotypes may be of great clinico-pathologic interest. In this study we determined the effective prevalence of coinfections by two or more HCV genotypes in 213 subjects with HCV-positive chronic hepatitis by using genotype-specific polymerase chain reaction (PCR), genotype-specific probe hybridization, and direct sequencing. The most prevalent genotype was HCV-1b (54%). HCV-2 (a/c) was also prevalent (27%), and types 1a and 3a were found in 5% and 3% of patients, respectively. A mixed infection was detected in 23 patients (10.8%): 4 out of 23 were coinfected by types 1a + 1b, while the remaining 19 patients had a b + 2 (a/c) mixed infection. Further analysis based on restriction fragment length polymorphism (RFLP) on type-specific PCR products was used to verify genotyping results. Only four coinfections (1a + 1b in 2 patients and 1b + 2 (a/c) in the remaining 2 patients, respectively) were confirmed by enzyme cleavage. All patients with true coinfection had long-lasting infection and liver cirrhosis. Both true and false mixed infections resulting from RFLP analysis were confirmed by direct sequencing of type-specific amplification products. We also determined a recurrent C/T transversion at position 618 in all sequenced samples. In 4 cases another point mutation (G/A at position 626) was found, reducing the number of mismatches between HCV-2 and HCV-1b from 4 to 3 (or 2). Interestingly, all HCV-2 isolates sequenced showed the highest degree of nucleotide homology with HCV-2 subtype c, confirming the relatively high prevalence of this subtype in Italy. In conclusion, we showed the possibility of multiple infection by different HCV types in the general population of chronically infected patients without particular risk factors, even if in a low percentage of cases. Further studies are needed to assess the clinical relevance of chronic HCV infection with multiple genotypes.

Vertical transmission of HCV

BACKGROUND

Knowledge about vertical transmission of HCV is still limited. In this study we followed up the virological status of a series of offspring born to anti-HCV positive, anti-HIV negative mothers.

METHODS

Between January 1993 and January 1995, 5000 consecutive, anti-HIV negative pregnant women were screened for anti-HCV (ELISA III) and all positive samples were confirmed by RIBA III and analyzed for HCV-RNA by polymerase chain reaction (PCR). Babies born to anti-HCV positive mothers were followed from birth to two years by testing for ALT levels, anti-HCV antibodies and HCV-RNA.

RESULTS

Of 5000 mothers 80 (1.6%) were anti-HCV positive (ELISA III) and RIBA III positive. Of these, 56 (70%) were HCV-RNA positive. We examined 80 babies, born to anti-HCV positive mothers: 56 with HCV-RNA positive mothers and 24 with HCV-RNA negative mothers. Two babies (3.6%) of 56 were anti-HCV and HCV-RNA positive, with normal liver function tests. Seventy-eight babies (97.5%) of 80 (54 with HCV-RNA positive mothers and 24 with HCV-RNA negative mothers) were HCV-RNA negative, with normal liver function tests and detectable levels of anti-HCV antibodies that gradually disappeared between 8-12 months.

CONCLUSION

Mother-to-infant transmission of HCV is possible only in the case of HCV-RNA positive mothers. In our study the rate of transmission is 3.6%, (2/56 babies with HCV-RNA positive mothers). HCV transmission may occur without evident association with breast-feeding or vaginal delivery.

Interferon and thymosin combination therapy in naive patients with chronic hepatitis C: preliminary results

AIMS/BACKGROUND

This randomized study was performed to compare the efficacy of interferon-alpha (IFN-alpha) + thymosin alpha 1 (Talpha1) treatment to that of IFN-alpha alone in light of biochemical and virological response of naive patients with chronic hepatitis C.

METHODS

Seventeen patients were treated with IFN alpha-2b (3 million units MU three times a week) + Talpha1 (1 mg twice weekly); the other 17 patients received only IFN alpha-2b at the same dose. All patients were treated for 6 months and followed up for 12 months. Biochemical (ALT values) and virological (HCV-RNA) responses to treatment were determined.

RESULTS

Combination therapy showed significantly higher efficacy than monotherapy in achieving biochemical and virologic end-of-treatment response (p<0.05). At 12 month follow-up, the sustained biochemical response was slightly greater in patients treated with combination therapy than in those treated with monotherapy. No significant difference in response by HCV-1b subtype was observed between the two treatment groups; however, HCV-2c subtype showed a trend to responding better to IFN-alpha+Talpha1 than to IFN-alpha alone.

CONCLUSIONS

These data suggest that the immune modulator Talpha1 may be additive or synergistic with IFN-alpha in normalizing end-treatment biochemical and virological responses in patients with chronic hepatitis C. Higher doses and/or more prolonged courses may improve the sustained response rates to this treatment.

Prevalence of monoclonal gammopathies in patients with hepatitis C virus infection

BACKGROUND

An association between monoclonal gammopathies and chronic liver diseases has been reported.

OBJECTIVE

To determine the prevalence of monoclonal gammopathies in patients with chronic hepatitis C virus (HCV) infection and the possible association of monoclonal gammopathies with HCV genotypes.

DESIGN

Prospective study.

SETTING

Departments of internal medicine and hematology at two university hospitals in Italy.

PATIENTS

239 HCV-positive and 98 HCV-negative patients with chronic liver diseases were recruited consecutively.

MEASUREMENTS

Clinical data were gathered, liver histologic examination was done, serum immunoglobulin and cryoglobulin levels were measured, and immunoelectrophoresis was done for monoclonal component detection. Patients with monoclonal gammopathy had serum HCV RNA measured and HCV genotype determined by polymerase chain reaction and had histologic examination of bone marrow.

RESULTS

Monoclonal band was detected in 11% of HCV-positive patients and in 1% of HCV-negative patients (P = 0.004). The prevalence of HCV genotype 2a/c was higher in patients with monoclonal gammopathies than in those without (50% compared with 18%; P = 0.009).

CONCLUSION

The prevalence of monoclonal gammopathies in patients with HCV-related chronic liver disease is striking and is often associated with genotype 2a/c infection.

Hepatitis C virus persistence in human hematopoietic cells injected into SCID mice

The issue of infection of peripheral blood mononuclear cells (PBMC) by the hepatitis C virus (HCV) has potentially important implications, but is still debated. We have used the severe combined immunodeficiency (SCID) mouse model to test for the persistence of HCV in PBMC. Hematopoietic cells isolated from 14 subjects infected by HCV were inoculated intraperitoneally into SCID mice. Serum and blood cell samples from these mice were obtained with a mean follow-up of 8 weeks. As controls, human fibroblasts and sheep PBMC, preincubated with a human HCV-positive serum, were inoculated concomitantly into mice and analyzed. HCV-RNA positive strands were detected in 7 of 26 serum samples and 8 of 26 cell fractions from SCID mice inoculated with HCV-positive PBMC, after 8 weeks of follow-up. In contrast, no HCV RNA was detectable in the 10 control mice. HCV-RNA negative strands were detected in only 2 of 10 tested samples from 2 mice, and both positive mice had been inoculated with PBMC from HCV-positive subjects with malignant hematopoietic syndrome. Our study offers strong evidence for the persistence of HCV infection in mononuclear cells. Our results are also consistent with a low rate of HCV multiplication. This SCID mouse model might therefore be useful in analyzing the mechanisms of HCV persistence in mononuclear cells.

Mixed cryoglobulinaemia: a cross-road between autoimmune and lymphoproliferative disorders

Mixed cryoglobulinaemia (MC) is a systemic vasculitis, secondary to the deposition in small and medium-sized blood vessels of circulating immune complexes, mainly the cryoglobulins, and complement. MC is characterised by a typical clinical triad (purpura, weakness, arthralgias) and by one or more organ involvement: chronic hepatitis, glomerulonephritis, peripheral neuropathy, skin ulcers and diffuse vasculitis. In a limited number of MC patients, a malignancy, that is B-cell non-Hodgkin's lymphoma or hepatocellular carcinoma, may also develop. Hepatitis C virus (HCV) infection has been found in the majority of patients with MC; the frequency of HCV markers (91%) was significantly higher than other rheumatic diseases (6.4%), namely systemic lupus, Sjögren's syndrome, rheumatoid arthritis and systemic sclerosis, or healthy controls (1.2%). The HCV infection of lymphoid tissues may represent the remote event leading to B-lymphocyte proliferation responsible for autoantibodies and immune-complex production. In a similar way, HCV infection may also be involved in the pathogenesis of other autoimmune (glomerulonephritis, thyroiditis, lung fibrosis, autoimmune hepatitis, porphyria cutanea tarda) and lymphoproliferative disorders (monoclonal gammopathies, B-cell lymphomas). MC shares numerous clinico-serological and pathological features with the above disorders. HCV seems to be their common etiological agent; however, a variable combination of unknown co-factors (infectious, genetic, environmental) should be determinant for the appearance of different clinical patterns.

Universal precautions and dedicated machines as cheap and effective measures to control HCV spread

Haemodialysis patients are at great risk for HCV infection, and a strict relationship is clear between anti-HCV positivity and dialysis age or hospital dialysis, irrespective of previous blood transfusions. Notwithstanding that, the precise root of its nosocomial nontransfusional diffusion among haemodialysis patients is not clear yet. As isolation is a very expensive policy, we evaluated whether simpler measures such as the observance of the Universal Precautions (UP), and the use of anti-HCV positive patient dedicated monitors can stop the diffusion of HCV infection in a hospital haemodialysis centre. Since January 1990 to December 1991 (1st phase), the patients shared the monitors irrespective of their serological status for HCV, and training of the dialysis care staff was not performed with regard to the UP. Since January 1991 to June 1996 (2nd phase), according to the UP, strictly personal dialysis-tools were used for all patients, anti-HCV positive patients were assigned to dedicated monitors in defined (not separated) areas of the dialysis rooms and the dialysis care staff was trained to the strict observance of the UP. In the first phase of the follow-up 5 seroconversions occurred; none occurred in the second one. Our study shows that isolation is not required for such patients. We believe that measures such as the application of UP, dedicated machines and continuous training of the care staff, instead of the isolation of positive patients, result in the same efficacy and are cheaper than isolation of positive patients. Therefore they are mandatory for all haemodialysis centres.

Impaired response to alpha interferon in patients with an inapparent hepatitis B and hepatitis C virus coinfection

The possibility of hepatitis B virus (HBV) infection in HBsAg-negative patients has been shown. However, an "inapparent" coinfection by HBV in hepatitis C virus (HCV)-positive patients generally is not taken into account in clinical practice. Mechanisms responsible for resistance to interferon (IFN) have not been completely clarified. The aim of this study was to investigate whether an "inapparent" coinfection by HBV in anti-HCV-positive chronic liver disease patients may influence IFN response. Fourteen anti-HCV positive, HBsAg-negative but serum HBV DNA-positive patients by PCR and 111 anti-HCV-positive, HBsAg-negative and HBV DNA (PCR)-negative patients with chronic hepatitis were treated with 3 MU of recombinant alpha-2a IFN 3 times weekly for 12 months. Serum HBV DNA and HCV RNA were determined before treatment, after 6-12 months and in coincidence with ALT flare-up by PCR. HBV PCR was performed using primers specific for the S region of the HBV genome and HCV PCR with primers localised in the 5'NC region of HCV genome. IgM anti-HBc was tested using IMx Core-M Abbott assay. By the end of treatment, ALT values had become normal in 4/14 HBV DNA-positive patients (28%), but all "responders" (4/4) relapsed between 2 and 5 months after therapy. All but one patient were HCV RNA-positive before treatment, 6 were also both HBV DNA and HCV RNA-positive during ALT flare-ups. In 5 patients, only HBV DNA and in 3 patients, only HCV RNA was detected when transaminase values increased. All patients remained HBsAg-negative and anti-HCV-positive. IgM anti-HBc was detected both before treatment and during ALT elevation in 3 patients and only during ALT relapse in 3 others. Of the 111 anti-HCV positive, HBsAg-negative and HBV DNA (PCR)-negative patients with chronic hepatitis, a biochemical response to IFN treatment was observed in 54% of the cases. Relapse of ALT values was observed in 47% of the cases during a follow-up of 1 year after treatment. "Inapparent" HBV/HCV coinfection may be implicated in cases of resistance to IFN treatment. In addition, HBV replication may persist in patients in whom HCV replication was inhibited by IFN treatment. The pathogenic role of HBV in liver disease was confirmed by detection of IgM anti-HBc in some cases; the appearance of these antibodies only after IFN treatment suggests that IFN may exert a selective role in favour of HBV. Further studies will show the effect of different treatment schedules. HBV DNA and/or IgM anti-HBc detection with very sensitive methods may be important both as a prognostic factor and as a tool for better understanding interviral relationships and mechanisms involved in multiple hepatitis virus infections.

Hepatitis C virus infection in mixed cryoglobulinemia and B-cell non-Hodgkin's lymphoma: evidence for a pathogenetic role

We investigated the pathogenetic relevance of hepatitis C virus (HCV) infection in mixed cryoglobulinemia (MC) with or without complicating B-cell Non-Hodgkin's lymphoma (NHL) in comparison with other immunological and lymphoproliferative disorders. The following groups of patients were studied: A) 25 patients with MC in 7 cases evolved into B-cell NHL; B) 25 healthy subjects; C) 22 patients with different systemic immune diseases; D) 24 patients with chronic HCV infection without MC; E) 25 patients with B-cell idiopathic NHL. Methods used included: i) Polymerase chain reaction (PCR) for HCV RNA detection in serum and peripheral blood mononuclear cells (PBMC) (uncultured or mitogen-stimulated); ii) Branched DNA (b-DNA) for HCV RNA quantification; iii) HCV genotyping by genotype-specific primers localized in the core region and by hybridization of amplification products of the 5' untranslated region (5'UTR), obtained with universal primers, using genotype-specific probes. Serum anti-HCV and HCV RNA were detected in 88% and 73% of MC patients, respectively, and in a significantly lower percentage of healthy controls and patients with autoimmune diseases. HCV RNA concentration was significantly lower in supernatants than in corresponding whole sera (p < 0.001). Plus-strand HCV RNA was detected in 81% of peripheral blood mononuclear cell (PBMC) samples and minus-strand in the majority of fresh or mitogen stimulated cells. All MC patients with NHL had HCV RNA sequences in PBMC. HCV genotype 2a/III was detected in MC patients with a prevalence that was significantly higher than in HCV infected patients without MC. Surprisingly, HCV markers (anti-HCV and/or HCV RNA) were found in 32% of patients with idiopathic NHL. These data suggest that HCV infection is involved in the pathogenesis of MC through both direct participation in the immune complex related vasculitis and by triggering the lymphoproliferative disorder underlying the disease. This latter disorder seems to be related to HCV lymphotropism which could also be responsible for the evolution of MC to malignant lymphoma. This study also suggests that HCV infection may be involved in the pathogenesis of idiopathic B-cell NHL through a similar pathogenetic mechanism.