Genetic Association of Hepatitis C-Related Mixed Cryoglobulinemia: A 10-Year Prospective Study of Asians Treated with Antivirals

Genetic profiles of hepatitis C virus (HCV)-associated mixed cryoglobulinemia (MC) in Asians remain elusive. A 10-year prospective cohort study was conducted with 1043 consecutive HCV Ab-positive Taiwanese surveyed with 13 single nucleotide polymorphisms (SNPs). Of 1043, 589 (56.5%) had baseline MC, 934 (89.5%) had positive HCV RNA, 796 completed anti-HCV therapy, and 715 had sustained virological responses (SVRs). SNP associations were surveyed withgenotypic, allelic, trend, permutation and multivariate analyses. At baseline, higher male sex and MC rates were noted in HCV RNA-positive than RNA-negative patients; higher female sex and positive HCV RNA rates but lower HCV RNA levels were noted in patients with than those without MC. Baseline associations were: HLA II-rs9461776 A allele, IFNL3-rs12979860 T allele, SERPINE1-rs6976053 C allele and MC with HCV RNA positivity; IFNL3-rs12979860 C allele, ARNTL-rs6486122 T allele and HCV RNA positivity with baseline MC. In SVR patients, RETN-rs1423096 C allele and SERPINE1-rs6976053 T allele were associated with 24-week and 10-year post-therapy MC, respectively. Conclusions: HCV RNA, IFNL3-rs12979860 and ARNTL-rs6486122 were associated with baseline MC; RETN-rs1423096 and SERPINE1-rs6976053 were associated with short- and long-term post-therapy MC in SVR patients, respectively. Links with HCV RNA and immune-associated SNPs suggest MC an immune reaction to expel HCV.

Immunogenetics of complement in mixed cryoglobulinaemia

OBJECTIVES

A low C4 level is one of the hallmarks of mixed cryoglobulinaemia (MC). However, several reports suggest that other factors may be involved in C4 depletion. The C4 gene is located in a multiallelic CNV locus in the human MHC region. We studied the C4 gene copy number (GCN) and both C4A and C4B isotypes, as well as the presence of the hypofunctional C4A6 allotype (rs41315824) and C4A0 allotype (rs367709216) in 41 MC patients, 16 SLE patients and 78 healthy controls.

METHODS

GCN of the C4 gene were evaluated by real time PCR. C4A6 allotype (p.Arg458Trp) and ins 2-bp mutation in exon 29 were screened by primer extension. Correlation with clinical signs of the disease (cutaneous ulcers, peripheral neuropathy, GN, purpura, hepatitis) have been performed by cluster analysis, (K-means algorithm).

RESULTS

C4 GCN analysis showed that fewer MC patients had more than 2 copies of the C4A gene as well as a lower C4A gene-copy index (1.90 ± 0.54 vs. 2.21 ± 0.78) as compared to healthy controls. SNP rs41315824 analysis showed a significant increase in the frequency of the p.Arg458Trp (C4A6) variant in cryoglobulinaemic patients. Lastly, cluster analysis allowed us to identify two separate clusters of patients. The cluster that included patients with three or less C4 gene copies was found to have a greater prevalence of the most severe complications such as glomerulonephritis, neuropathy and severe cutaneous ulcers.

CONCLUSIONS

These data suggest there may be a relationship between polymorphisms of the C4 gene and clinical presentation.

Genome-Wide Association Studies and Hepatitis C: Harvesting the Benefits of the Genomic Revolution

Utilizing genome-wide association studies (GWASs) to examine the variation in hepatitis C virus (HCV) phenotypes has led to quantum improvements in our understanding of both the genetic basis and the underlying pathogenesis of HCV infection. In this context, the discovery of interferon lambda polymorphisms is unique with far reaching implications that extend well beyond HCV to various other liver and extrahepatic diseases. In this review, we summarize the data on the impact of GWASs on our understanding of HCV disease.

Role of IL28B genotyping in patients with hepatitis C virus-associated mixed cryoglobulinemia and response to PEG-IFN and ribavirin treatment

The role of interleukin (IL) 28B in the treatment of chronic hepatitis C (CHC) has recently been examined in many studies, while a possible relationship between IL28B and the presence of mixed cryoglobulinemia (MC) remains to be clarified. In this study, we analyzed the influence of IL28B rs8099917/rs12979860 on the presence of MC and the role in treatment with PEG-IFN. We retrospectively examined 541 patients affected by CHC who were treated with pegylated interferon (PEG-IFN) and ribavirin from 2003 to 2012. We included all treatment-naïve patients without other viral co-infections or major contraindications to the PEG-IFN and ribavirin standard of care. One hundred seventy-five patients (32.3 %) had MC; 49 of these (33.3 %) had symptomatic MC. The IL28B rs8099917/rs12979860 TT/CC genotype was the most frequent in MC-positive patients with sustained virological response (SVR) (p < 0.001), while the TG/TC genotype was most frequent in non-SVR (p < 0.001). The TT/CC genotype was found to be the main positive predictive factor of MC in HCV patients (OR = 11.914; IQR = 7.092-18.776; p < 0.001); HCV genotype 2/3 was the strongest positive predictive factor of SVR (OR = 10.448; IQR = 8.352-21.561; p < 0.001); IL28B rs8099917/rs12979860 TT/CC was a better predictive factor than rs12979860 CC alone (OR = 9.829 vs. 2.663). Negative predictive factors were Metavir score F3-F4 (OR = 0.625; IQR = 0.416-0.779; p = 0.008), insulin-resistance (OR = 0.315; IQR = 0.224-0.585; p < 0.001) and presence of symptoms (OR = 0.716; IQR = 0.492-0.855; p < 0.001). IL28B rs8099917/rs12979860 is useful in the treatment of MC-positive HCV patients with PEG-IFN and ribavirin; the TT/CC genotype is associated with SVR, the TG/TC with non-SVR; TT/CC is also predictive of MC in HCV patients.

Interleukin 28B gene polymorphisms in hepatitis C virus-related cryoglobulinemic vasculitis

OBJECTIVE

Single-nucleotide polymorphisms (SNP) in the interleukin 28B (IL-28B) gene region are strongly predictive of the response of infected patients to antiviral therapy for hepatitis C virus (HCV). We sought to determine the prevalence of SNP IL-28B rs12979860 C/C and non-C/C (C/T plus T/T) genotypes in HCV-related cryoglobulinemic vasculitis (CV), as compared with HCV-positive patients without CV. We also searched for their association with peculiar clinical manifestations of CV and potential influence on the complete response (virological, molecular, and immunological) to the therapy.

METHODS

The study cohort comprised 159 and 172 HCV-infected patients with and without CV, respectively, prospectively followed starting from 1990. SNP rs12979860 genotyping was performed by Taq-Man allelic discrimination. In 106 patients (66.6%) with CV, the profile of circulating B cell clonalities was determined as well. All patients with CV were treated with pegylated interferon-α/ribavirin-based antiviral therapy.

RESULTS

The T/T IL-28B genotype was more common in patients with CV than in those without (17% vs 8.1%, p = 0.02). In patients with CV, compared with non-C/C variants, the IL-28B C/C genotype was associated with a higher rate of complete response (52.6% vs 39.2%, p = 0.13), whereas a treatment response of 61.4% was demonstrated when solely virological response was considered (p = 0.008). A higher frequency of expanded B cell clonalities in the circulation (84.2% vs 55.9%; p = 0.005), kidney involvement (21% vs 2.9%; p = 0.003), and B cell non-Hodgkin lymphoma (17.5% vs 6.8%; p = 0.048), were also observed.

CONCLUSION

In HCV-positive patients with CV, the IL-28B C/C genotype is distinguished biologically by a higher frequency of restriction of B cell response and clinically by a higher risk of cryoglobulinemic nephropathy and B cell malignancies, while acting as an independent predictor of a sustained virological response to antiviral therapy. In addition, we found that IL-28B T/T variant was more prevalent in patients with CV than in those without.

Hepatitis C virus-related mixed cryoglobulinemia: Is genetics to blame?

Mixed cryoglobulinemia (MC) is the extrahepatic manifestation most strictly correlated with hepatitis C virus (HCV) infection; it is a benign autoimmune and lymphoproliferative disorder that evolves to lymphoma in 5%-10% of cases. MC is reputed to be a multistep and multifactorial process whose pathogenicity is still poorly understood. It is still unknown why only some chronically infected HCV patients develop MC and only some of these exhibit systemic symptoms (MC syndrome). Several studies have investigated the pathogenetic basis of MC and the most recent ones suggest that the virus is able to trigger such a disorder only in the presence of genetic factors that are still unknown. Here, we try to clarify the complex relationship between HCV-related MC and the host’s genetic background. The data that we report are heterogeneous and sometimes even conflicting. Therefore, large, multicenter studies are clearly needed. The identification of a characteristic genetic signature of cryoglobulinemic patients would be an important step toward a personalized approach in their clinical care. The new wide-ranging genomics technologies will hopefully help to resolve these complex issues.

Expansion of autoreactive unresponsive CD21-/low B cells in Sjögren's syndrome-associated lymphoproliferation

OBJECTIVE

Primary Sjögren's syndrome (SS) is an autoimmune disease associated with a high risk of developing non-Hodgkin's lymphoma. This study was undertaken to determine the nature of B cells driving lymphoproliferation in primary SS.

METHODS

B cell subsets and function were analyzed in peripheral blood from 66 adult patients with primary SS (including 14 patients with B cell lymphoproliferative disease [LPD]) and 30 healthy donors, using flow cytometry, calcium mobilization, and gene array analysis. The reactivity of recombinant antibodies isolated from single B cells from patients with primary SS and LPD was tested using an enzyme-linked immunosorbent assay.

RESULTS

We observed an expansion of an unusual CD21-/low B cell population that correlated with lymphoproliferation in patients with primary SS. A majority of CD21-/low B cells from patients with primary SS expressed autoreactive antibodies, which recognized nuclear and cytoplasmic structures. These B cells belonged to the memory compartment, since their Ig genes were mutated. They were unable to induce calcium flux, become activated, or proliferate in response to B cell receptor and/or CD40 triggering, suggesting that these autoreactive B cells may be anergic. However, CD21-/low B cells from patients with primary SS remained responsive to Toll-like receptor (TLR) stimulation. Molecules specifically expressed in CD21-/low B cells that are likely to induce their unresponsive stage were detected in gene array analyses.

CONCLUSION

Patients with primary SS who display high frequencies of autoreactive and unresponsive CD21-/low B cells are susceptible to developing lymphoproliferation. These cells remain in peripheral blood controlled by functional anergy instead of being eliminated, and chronic antigenic stimulation through TLR stimulation may create a favorable environment for breaking tolerance and activating these cells.

Role of microRNA profile modifications in hepatitis C virus-related mixed cryoglobulinemia

Hepatitis C virus infection is closely related to lymphoproliferative disorders (LPDs), including mixed cryoglobulinemia (MC) and some lymphomas. Modification of the expression of specific microRNAs (miRNAs) has been associated with different autoimmune diseases and/or LPDs. No data exist about the modifications in miRNA expression in HCV-associated LPDs. The aim of this study was to analyze the expression levels of a panel of miRNAs previously associated with autoimmune/LPDs in a large population of HCV patients with and without MC or non-Hodgkin’s lymphoma (NHL), to identify potential markers of evolution of HCV infection. PBMC expression of miR-Let-7d, miR-16, miR-21, miR-26b, miR-146a and miR-155 was evaluated by real-time PCR in 167 HCV patients (75 with MC [MC-HCV], 11 with HCV-associated NHL [NHL-HCV], 81 without LPD [HCV]) and in 35 healthy subjects (HS). A significant increase in miR-21 (p<0.001), miR-16 (p<0.01) and miR-155 (p<0.01) expression was detected in PBMCs from only NHL patients whereas a significant decrease in miR-26b was detected in both MC and NHL subjects (p<0.01) when compared to HS and HCV groups. A restoration of miR-26b levels was observed in the post-treatment PBMCs of 35 HCV-MC patients experiencing complete virological and clinical response following antiviral therapy. This study, for the first time, shows that specific microRNAs in PBMC from HCV patients who developed MC and/or NHL are modulated differently. The specific, reversible downregulation of miR-26b strongly suggests the key role it plays in the pathogenesis of HCV-related LPDs and its usefulness as a biomarker of the evolution of HCV infection to these disorders.

Value of IL28B genotyping in patients with HCV-related mixed cryoglobulinemia: results of a large, prospective study

HCV-related mixed cryoglobulinemia (MC) is characterized by clonal expansion of B cells producing a polyreactive natural antibody (rheumatoid factor) and interferon (IFN)-based therapy is the first therapeutic option in mild-moderate MC. Single nucleotide polymorphisms (SNPs) proximal to genes involved in the innate response (IL28B/IFN-λ gene family) are strongly associated with spontaneous and IFN-induced viral clearance in hepatitis C, but no data exist about their role in HCV-positive MC. A large cohort of patients with HCV and MC was studied to evaluate the influence of IL28B genotype on the response to treatment and/or the evolution to MC of HCV infection. The rs12979860/rs8099917 IL28B polymorphisms were analysed in 481 consecutive HCV-positive subjects (250 with MC and 231 without MC, as controls) using real-time PCR and direct sequencing. Hundred and fifteen HCV patients with MC received standard anti-HCV therapy, and the results were evaluated according to the IL28B SNP distribution. Similar IL28B SNPs allele frequencies were recorded for patients and controls. IL28B major allele homozygosis (for both SNPs tested) was tightly correlated with virological and clinical response (P = 0.002). A statistically significant association was limited to 'difficult-to-treat' (G1/4) HCV genotypes. The IL28B genotype was a strong independent predictor of response (P = 0.007, OR 6.06; CI 1.65-22.22). The IL28B genotype was confirmed to be a useful predictor of response to IFN-based therapy in patients with HCV and MC. The very close correlation between IL28B SNP distribution, virological and clinical response definitively confirmed the key role played by HCV in MC. Conversely, the IL28B genotype does not seem to influence the evolution to MC.

T(14;18) is not associated with mixed cryoglobulinemia or with clonal B cell expansion in egyptian patients with hepatitis C virus infection

BACKGROUND/AIM

The mechanisms of B-cell lymphoproliferative disorders in chronic hepatitis C virus (HCV) infection are unclear. An increased prevalence of circulating monoclonal B-cells and t(14;18) has been reported. Geographic heterogeneity of prevalence of t(14;18) has been shown to exist. We investigated the prevalence of t(14;18) and B-cell clonality as possible mechanisms of lymphomagenesis in chronic HCV patients, in whom cryoglobulinemia status was previously detected.

METHODS

A cohort of 111 patients was studied, including 87 patients with chronic HCV disease (18 cryoglobulinemic and 69 non- cryoglobulinemic); 24 HCV-negative, cryoglobulin negative patients with other nonimmune chronic liver diseases were enrolled as controls. The t(14;18) and IgH rearrangement (as a marker of B-cell clonality) were detected by the polymerase chain reaction.

RESULTS

t(14;18) was detected in 27.6% of HCV patients and in none of the controls. Detection rates were comparable in both cryoglobulin-positive and negative groups (22.2% and 29% , respectively), p=0.769. IgH rearrangement was detected in 39.1% of HCV patients and in none of the controls. The cryoglobulin-positive group showed significantly higher prevalence of IgH rearrangement compared to the cryoglobulin-negative group (61.1% and 33.3% , respectively), p=0.03, OR=3.13 and 95% CI=1.07-9.17. t(14;18) and monoclonal IgH rearrangement detection rates were not associated with each other, p=0.467.

CONCLUSIONS

t(14;18) is uncommon in HCV-mixed cryogoblulinemia Egyptian patients; it does not seem to play a role in HCV-associated MC and lymphomagenesis in our geographical area. HCV may play a role in mixed cryogoblulinemia and lymphomagenesis, probably by inducing clonal B-cell expansions.

Clonal expansion of immunoglobulin M+CD27+ B cells in HCV-associated mixed cryoglobulinemia

Hepatitis C virus (HCV) is associated with B-cell lymphoproliferative disorders such as mixed cryoglobulinemia (MC) and B-cell non-Hodgkin lymphoma (B-NHL). The pathogenesis of these disorders remains unclear, and it has been proposed that HCV drives the pro-liferation of B cells. Here we demonstrate that certain HCV(+)MC(+) subjects have clonal expansions of immunoglobulin M (IgM)(+)kappa(+)IgD(low/-)CD21(low)CD27(+) B cells. Using RT-PCR to amplify Ig from these singly sorted cells, we show that these predominantly rheumatoid factor-encoding V(H)1-69/J(H)4 and V(kappa)3-20 gene segment-restricted cells have low to moderate levels of somatic hypermutations. Ig sequence analysis suggests that antigen selection drives the generation of mutated clones. These findings lend further support to the notion that specific antigenic stimulation leads to B-cell proliferation in HCV MC and that chronic B-cell stimulation may set the stage for malignant transformation and the development of B-NHL. The finding that these hypermutated, marginal zone-like IgM(+)CD27(+) B cells are clonally expanded in certain subjects with MC offers insight into mechanisms of HCV-associated MC and B-cell malignancy. This study was registered at www.clinicaltrials.gov as NCT00219999.

Fibronectin gene polymorphisms are associated with the development of B-cell lymphoma in type II mixed cryoglobulinemia

OBJECTIVE

To analyse fibronectin (FN) gene polymorphisms in type II mixed cryoglobulinemic syndrome (MCsn), an immune-complex mediated systemic vasculitis linked to hepatitis C virus (HCV) infection and characterised by rheumatoid factor (RF) positive B-cell proliferation at high risk for the progression into non-Hodgkin's lymphoma (NHL).

METHODS

Samples from 74 patients with MCsn (type II serum cryoglobulins and clinical signs of vasculitis) were studied. In all, 58 (78.4%) patients were HCV-positive. In total, 21 (28.4%) patients developed a B-cell NHL during the course of MCsn. A total of 72 patients with HCV-negative and MC-unrelated NHL and 110 healthy blood donors (HBDs) were taken as controls. HaeIIIb and MspI FN gene polymorphisms were analysed by PCR and specific restriction enzyme digestions, following reported procedures. Plasma FN levels were analysed by ELISA, whenever possible.

RESULTS

HaeIIIb and MspI allele and genotype frequencies did not differ between MCsn patients and HBDs. Of note, the DD-MspI (OR = 5.99; CI 1.77-20.261, p = 0.0039) and the AA-HaeIIIb (OR = 4.82, CI 1.42-16.39, p = 0.0176) homozygosis appeared significantly associated with the development of B-cell NHL in MCsn patients, with the HaeIIIb A allele possibly conferring an increased risk of NHL in the general population (OR = 1.72, CI 1.128-2.635, p = 0.0133). None of the other MCsn-related clinical manifestations were significantly associated with a particular genetic pattern. No association between FN plasma levels and FN genotypes was found.

CONCLUSION

Genotyping for MspI and HaeIIIb FN gene polymorphisms may be clinically relevant to define the risk of lymphoma development in MCsn.

Relationship of HLA antigens and cryoglobulinaemia in hepatitis C virus infected patients

OBJECTIVE

To find the relationship between human leukocyte antigens (HLA) and cryoglobulin positivity in hepatitis C virus (HCV) infected individuals.

METHODS

Eligible individuals selected from pre and post renal transplant settings were divided into three groups. Group A (n = 301) consisted of normal controls, while group B (n = 200) comprised of pathological controls that were HCV antibody (anti-HCV) positive but negative for cryoglobulins. Group C comprised of 56 anti-HCV positive, cryoglobulin positive patients. HLA-A, -B and -DRB1 loci were typed by polymerase chain reaction (PCR) method and relationship between HLA antigens, anti-HCV status and cryoglobulinaemia was analyzed.

RESULTS

HLA-A*02, -B*57 and -DRB1*03 were more frequently found among group C members as compared to groups A and B. Only HLA-B* 57 occurrence reached statistical significance (14.3% versus 6% and 4%, corrected P-value = 0.045 and 0.012 and OR = 2.6 and 4 respectively) No differences in the distribution of HLA antigens were seen among healthy and pathological controls.

CONCLUSION

The presence of HLA-B*57 confers susceptibility to cryoglobulinaemia in HCV infected patients in our population. HCV positive renal transplant recipients with these alleles should be monitored for cryoglobulin formation).

Analysis of hepatitis C virus hypervariable region 1 sequence from cryoglobulinemic patients and associated controls

Chronic hepatitis C virus (HCV) infection is frequently associated with extrahepatic manifestations, including nonmalignant and malignant B-cell lymphoproliferative disorders. It has been reported that specific changes or recurring motifs in the amino acid sequence of the HCV hypervariable region 1 (HVR1) may be associated with cryoglobulinemia. We searched for specific insertions/deletions and/or amino acid motifs within HVR1 in samples from 80 symptomatic and asymptomatic patients with and 33 patients without detectable cryoglobulins, all with chronic HCV infection. At variance with the results of a previous study which reported a high frequency of insertions at position 385 of HVR1 from cryoglobulinemic patients, we found a 6.2% prevalence of insertions in samples from patients with and a 9.1% prevalence in those without cryoglobulinemia. Moreover, statistical and bioinformatics approaches including Fisher's exact test, k-means clustering, Tree determinant-residue identification, correlation of mutations, principal component analysis, and phylogenetic analysis failed to show statistically significant differences between sequences from cryoglobulin-negative and -positive patients. Our findings suggest that cryoglobulinemia may arise by virtue of as-yet-unidentified host- rather than virus-specific factors. Specific changes in HCV envelope sequence distribution are unlikely to be directly involved in the establishment of pathological B-cell monoclonal proliferation.

Type II mixed cryoglobulinaemia as an oligo rather than a mono B-cell disorder: evidence from GeneScan and MALDI-TOF analyses

OBJECTIVE

To identify and characterize rheumatoid factor (RF)-producing B-cells and cryoprecipitate immunoglobulin (Ig) M in hepatitis C virus (HCV)-positive patients.

METHODS

We purified and characterized, by peptide mass fingerprinting integrated with an NCBI IgBlast data bank search, the IgM component of cryoprecipitate and analysed the VDJ pattern of bone marrow B-cells by gene scan analysis of 17 HCV-positive patients with type II mixed-cryoglobulinaemia.

RESULTS

IgM purified from all of the patients presented an RF specificity. In three of these patients a high and predominant B-cell clone (>or=30%) was found in the bone marrow. B-cell-receptor sequences were determined and immunophenotyping of these clones was performed. Peptide masses originating after tryptic digestion of the B-cell-receptor combinatory regions and those originating by tryptic digestion of the cryoprecipitated IgM from the same patient were comparable. In the remaining patients an oligoclonal/polyclonality was found. However, in some of these patients we were able to find peptides that matched with the B-cell-receptor sequences of overexpanded B cells, indicating that, even in the absence of a clear monoclonal expansion, a fraction of total cryoprecipated IgM may derive from overexpanded B-cell clones found in patients' bone marrow.

CONCLUSIONS

In the majority of mixed cryoglobulinaemia-HCV-positive patients, both in the serum and in B cells from the bone marrow, an oligoclonal pattern is the main molecular picture. When a monoclonal B-cell clone is found, its B-cell-receptor shows an antigen-binding fragment identical to that of cryoprecipitable RF-IgM. Phenotypically, B cells are CD20-positive but CD5-negative, suggesting that the B-1 B-cell subset is not likely to produce high-affinity IgM-RF molecules.

Successful treatment with adefovir of one patient whose cryoglobulinemic vasculitis relapsed under lamivudine therapy and who was diagnosed to have HBV virologic breakthrough with YMDD mutations

We report a patient whose cryoglobulinemic vasculitis recurred due to reactivation of lamivudine-resistant HBV. Our patient with hepatitis B-related cryoglobulinemic vasculitis was administered lamivudine. Her vasculitis regressed, ALT normalized, HBV-DNA became negative. Under lamivudine therapy, her cryoglobulinemic cutaneous vasculitis recurred. ALT increased significantly; it was found that tyrosine-methionine-aspartate-aspartate (YMDD) motif in the DNA polymerase gene had been replaced by YIDD. Adefovir was added to lamivudine. During follow-up, her purpura disappeared, ALT normalized, HBV-DNA became negative. Our patient is the first whose cryoglobulinemic vasculitis recurred under lamivudine, who had a HBV virologic breakthrough with YMDD mutation, and was successfully treated with adefovir.

Involvement of chemokines and type 1 cytokines in the pathogenesis of hepatitis C virus-associated mixed cryoglobulinemia vasculitis neuropathy

OBJECTIVE

To examine the expression profiles of a large number of genes within typical vasculitic nerve lesions in patients with mixed cryoglobulinemia (MC) vasculitis in order to better characterize the molecules involved in cellular tissue activation and trafficking.

METHODS

The quantitative expression of 19 genes coding for cytokines, chemokines, and their receptors in the nerve lesions of 9 patients with hepatitis C virus (HCV)-associated MC vasculitis, 7 with idiopathic polyarteritis nodosa (PAN) (rheumatic disease controls), and 8 patients with noninflammatory idiopathic neuropathy (noninflammatory neuropathy controls) was assessed using a real-time reverse transcriptase-polymerase chain reaction procedure.

RESULTS

Compared with the noninflammatory controls, HCV-MC vasculitis patients had a significantly higher expression of Th1 cytokines in vasculitic nerve lesions (mean +/- SEM fold increase 33.7 +/- 11.6 for interferon-gamma and 7.2 +/- 1.9 for tumor necrosis factor alpha), whereas Th2 cytokines were absent (interleukin-4 [IL-4], IL-5, and IL-13) or were not significantly different (IL-10). Chemokines involved in T cell and monocyte trafficking were also significantly up-regulated in the HCV-MC vasculitis patients (mean +/- SEM fold increase 27.4 +/- 8.3 for macrophage inflammatory protein 1alpha [MIP-1alpha], 19.9 +/- 5.7 for MIP-1beta, and 7.2 +/- 1.5 for CXCR3). Compared with patients with idiopathic PAN, there was a trend toward higher expression of MIP-1alpha and CXCR3 in HCV-MC vasculitis patients (mean +/- SEM fold increase 27.4 +/- 8.3 versus 5.3 +/- 3.4 for MIP-1alpha and 7.2 +/- 1.5 versus 2.5 +/- 0.9 for CXCR3).

CONCLUSION

This study is the first to demonstrate a role of cellular immunity and Th1 lymphocytes in the pathogenesis of HCV-MC vasculitic nerve lesions.

Study of host and virological factors of patients with chronic HCV infection and associated laboratory or clinical autoimmune manifestations

OBJECTIVE

Chronic hepatitis C virus (HCV) infection is associated with an array of autoimmune laboratory and clinical manifestations. The goals of our study were to identify host and/or virological factors that are implicated in the pathogenesis of these manifestations.

METHODS

We performed a detailed prospective study of various demographic, virological, biochemical, immunological (including lymphocyte subsets, Fc gamma-receptor and HLA class-II genotyping), histological and host genetic parameters in 3 well defined subgroups of HCV patients (n = 40): patients with liver disease only (group I, n = 11) or with laboratory (group II, n = 20) and clinical (group III, n = 9) autoimmune manifestations.

RESULTS

Group III patients, mainly with features of mixed cryoglobulinemia, were older, with higher levels of rheumatoid factor and circulating cryoglobulins while they tended to have a longer estimated disease duration compared to the other two groups of patients. We did not identify any specific immunological features that could differentiate symptomatic versus asymptomatic patients, except from the elevated soluble interleukin-2 receptor levels. An increased frequency of the R/R131 FcR gamma IIIA and the NA1/NA1 Fc gamma RIIIB genotypes was observed in our total HCV population, regardless of autoimmune manifestations, compared to historical controls. No statistically significant differences in HLA class II allele frequencies was detected between patient subgroups or in comparison to healthy controls.

CONCLUSIONS

Chronically infected HCV patients with symptomatic mixed cryoglobulinemia display a number of unique characteristics that differentiate them from asymptomatic patients with chronic hepatitis C.

Human IgG1/IgG3 cryoglobulin suggesting lack of allelic exclusion

Immunoglobulins undergoing cold-dependent precipitation are known as cryoglobulins. A type I cryoglobulin after Brouet et al. from serum of a patient with severe cutaneous vasculitis and membranoproliferative glomerulonephritis was purified by reversible temperature-dependent precipitation and analyzed using FPLC, Western blotting and peptide sequencing. The isolated cryoglobulin consisted of a single complex of a molecular weight of above 210kDa observed under non-reducing conditions in SDS-polyacrylamide gel electrophoresis (PAGE). Under reducing conditions, this complex resolved into three bands, two of which were reminiscent of Ig heavy (HC) chains and one of Ig-light chains (LC). The FPLC-purified type I cryoglobulin showed reversible precipitation analyzed by spectrophotometry. Delineation of the peptides involved in complex formation by immunoblot analysis and peptide sequencing revealed IgG3-V(H)4/Igkappa-VkappaIII/JkappaII and IgG1/V(H)3 molecules with evidence of somatic mutation. Coomassie blue-staining suggested that molar amounts of the IgG3-heavy chain were much higher than that of the IgG1-heavy chain. Treatment with SDS and boiling did not disrupt the unusually high molecular weight Ig complex. Pre-treatment of the cryoglobulin in 6M guadinium hydrochloride followed by gel filtration chromatography suggested covalent association of the IgG3, IgG1 and Igkappa molecules. Therefore, it might be that the cryoglobulin was produced by a single plasma B cell clone which passed immunological check-points in terms of B cell selection in the bone marrow in the absence of allelic exclusion, class switching and affinity maturation by somatic mutation.

A transgenic mouse model of autoimmune glomerulonephritis and necrotizing arteritis associated with cryoglobulinemia

Mice implanted with hybridoma secreting 6-19 IgG3 anti-IgG2a rheumatoid factor (RF) with cryoglobulin activity develop acute glomerulonephritis and cutaneous leukocytoclastic vasculitis. As the RF activity is implicated in the skin, but not glomerular lesions, it is still unclear whether the renal pathogenicity is determined by 6-19 H chains alone or their combination with L chains. To address this question, we have generated transgenic mice expressing only the H chain gene or both H and L chain genes of the 6-19 IgG3 anti-IgG2a RF and determined the development of glomerular and vascular lesions. H-single and H/L-double transgenic mice displayed comparable high amounts of IgG3 cryoglobulins, but only H/L-double transgenic mice having 10-fold higher levels of IgG3 anti-IgG2a RF progressively developed chronic, lethal glomerulonephritis. The severe glomerular lesions observed at 8-10 mo of age were very heterogeneous (membranoproliferative changes, crescents, and sclerosis); in addition, one-third of them had necrotizing arteritis in the kidneys and skeletal muscles. These renal and vascular changes were very different from those observed in the acute cryoglobulinemia, characterized by mainly "wire-loop" glomerular lesions and a cutaneous leukocytoclastic form of vasculitis. Thus, our data demonstrate the importance of a unique combination of the H and L chains for the expression of the pathogenic activity of IgG3 cryoglobulins and that a single autoantibody is able to induce different types of glomerular and vascular complications, depending on its production levels and kinetics.

Prevalence of bcl-2 rearrangement in patients with hepatitis C virus-related mixed cryoglobulinemia with or without B-cell lymphomas

BACKGROUND

Hepatitis C virus (HCV) infection is strictly associated with mixed cryoglobulinemia, a benign B-cell lymphoproliferative disorder that may evolve to lymphoma. An increased prevalence of bcl-2 rearrangement (the t(14;18) translocation) has been shown in patients infected with HCV.

OBJECTIVE

To evaluate the prevalence of bcl-2 rearrangement in patients with HCV-related mixed cryoglobulinemia and patients with chronic hepatitis but no cryoglobulinemia.

DESIGN

Prospective study.

SETTING

Two university hospitals.

PATIENTS

37 consecutively recruited patients with HCV-related mixed cryoglobulinemia and 101 patients with chronic HCV infection but without mixed cryoglobulinemia.

MEASUREMENTS

Clinical and serologic characteristics; liver biopsy; bcl-2 rearrangement, Bcl-2 expression, and the ratio of Bcl-2 to Bax in total peripheral blood mononuclear cells and cell subgroups; and sequence analysis of the junction of bcl-2 and IgH joining segments in positive samples.

RESULTS

Rearrangement of bcl-2 was observed in 28 of 37 (75.7%) patients with mixed cryoglobulinemia (65% of those with type III disease and 85% of those with type II disease, including 3 of 4 patients with lymphoma) and in 38 of 101 (37.6%) patients with chronic HCV infection but not mixed cryoglobulinemia (P < 0.001). Overexpression of Bcl-2 protein and a high ratio of Bcl-2 to Bax were observed in samples from patients with bcl-2 rearrangement. In 2 patients followed over time, peripheral blood cells bearing the t(14;18) translocation disappeared after antiviral therapy.

CONCLUSIONS

Rearrangement of bcl-2 was found with increased frequency in patients with chronic HCV infection and mixed cryoglobulinemia. The frequency was greatest in patients with type II mixed cryoglobulinemia. The high ratio of Bcl-2 to Bax in patients with bcl-2 rearrangement and disappearance of the rearrangement with antiviral therapy suggest that the translocation is associated with the antiapoptotic function of Bcl-2 and that HCV infection is linked to inhibition of B-cell apoptosis.

[Hepatitis C and immunoglobulin heavy-chain gene rearrangement]

Hepatitis C virus (HCV) has cytopathogenic effect not only on hepatocytes, however on salivary glands, monocytes of peripheral blood and lymphoid cells, may explain the systemic manifestations of the infection. HCV activates B and T-cells, modifies the immune response, causes lymphoproliferation, leading the development of B-cell non-Hodgkin's lymphoma (NHL). In the majority of B-cell NHLs immunoglobulin heavy chain (IgH) and light chain (IgL) genes are rearranged and expressed on cell surface in the early stage of the ontogenesis. The analyses of IgH rearrangement prove the clonality of lymphoproliferative disorders giving a powerful approach to the B-cell origin identification of cell proliferation.

PATIENTS AND METHODS

IgH gene rearrangements were examined from the sera of 57 chronic HCV infected patients and 11 HCV-positive cryoglobulinemic patients as well.

RESULTS

Cryoglobulinemia was detected in 20% of all chronic hepatitis C virus infected patients and IgH rearrangement was observed in 10.29% (7/68), 4/7 patients (57.14%) suffered from cryoglobulinemia.

CONCLUSIONS

These results support the hypothesis that IgH gene rearrangement in HCV positive patients can indicate the lymphoproliferative disorder in the HCV infection released B-cell proliferation and lymphoma development.

Genetic predispositions for the presence of cryoglobulinemia and serum autoantibodies in Chinese patients with chronic hepatitis C

Chronic hepatitis C virus (HCV) infection may induce immunological disorders in the host such as the presence of cryoglobulinemia or serum autoantibodies. The pathogenesis of these phenomena remains unclear but may reflect the host's genetic predispositions. The aim of this study was to evaluate the association between these immunological manifestations and human leukocyte antigen (HLA) expression in Chinese patients with chronic hepatitis C. The presence of serum cryoglobulin and autoantibodies (antinuclear antibody, antismooth muscle antibody, antimitochondrial antibody, antiliver-kidney-microsomal antibody) was determined in 122 Chinese patients with chronic hepatitis C. HLA class I and class II antigens were measured by microlymphocytotoxicity assay or by DNA typing in 122 chronic hepatitis C patients and 228 healthy controls. Of the 122 patients with chronic hepatitis C, 52 (43%) had cryoglobulinemia and 48 (39%) had serum autoantibodies. A significant difference in HLA frequency was noted for DR3, which was found in 36.5% of patients with cryoglobulinemia compared with 8.6% of patients without cryoglobulinemia and 11.3% of healthy controls. A significant difference in HLA frequency was also noted for DR4, which was found in 45.8% of patients with serum autoantibodies compared with 17.6% of patients without serum autoantibodies and 19% of healthy controls. Our results suggest the existence of HLA-linked susceptibility genes (DR3 or DR4) for the development of cryoglobulinemia or serum autoantibodies in Chinese patients with chronic hepatitis C.

Influence of HLA-DR phenotype on the risk of hepatitis C virus-associated mixed cryoglobulinemia

OBJECTIVE

Circumstances predisposing hepatitis C virus (HCV)-infected patients to develop mixed cryoglobulinemia (MC), which may manifest as a small-vessel systemic vasculitis (MC vasculitis), remain unclear. Previous studies have failed to demonstrate a clear role of either viral factors (genotype, viral load) or host factors (lymphocytes or immunoglobulin subsets). This study was undertaken to examine a possible role of HLA class II alleles in HCV-associated MC.

METHODS

One hundred fifty-eight HCV-infected patients, of whom 76 had MC (56 with type II MC and 20 with type III MC) and 82 did not have MC, were studied prospectively. MC vasculitis was noted in 35 HCV-infected patients with type II IgMkappa-containing cryoglobulins. HLA-DRB1 and HLA-DQB1 polymorphism was analyzed by hybridization using allele-specific oligonucleotides, after gene amplification. The odds ratio (OR) was calculated with Woolf's method. Then, using multivariate analysis, demographic, biologic, immunologic, virologic, and liver histologic factors associated with the presence of MC and MC vasculitis were investigated.

RESULTS

HLA-DR11 was significantly more frequent in patients with type II MC than in those without MC (41.1% versus 17.1%; OR 3.4, corrected P [Pcorr] = 0.017), regardless of the presence of vasculitis accompanying the MC (37.1% of those with MC vasculitis, 34.1% of those with MC but no vasculitis). HLA-DR7 was less frequent in HCV-infected patients with MC than in those without MC (13.2% versus 30.5%; OR 0.34, P = 0.012, Pcorr not significant), with a particularly lower frequency in those with type II MC and those with MC vasculitis (12.5% and 8.6%, respectively). There was no significant difference in HLA-DQB1 distribution between the different patient groups. By univariate and multivariate analysis, HLA-DR11 was the only positive predictive factor, besides female sex and advanced age, for the presence of MC and HCV-associated MC vasculitis (OR 2.58).

CONCLUSION

Our results indicate that the presence of the DR11 phenotype is associated with a significantly increased risk for the development of type II MC in patients with chronic HCV infection. In contrast, HLA-DR7 appears to protect against the production of type II MC. These results suggest that the host's immune response genes may play a role in the pathogenesis of HCV-associated MC.

Mixed cryoglobulinemia and hepatitis C virus association: ten years later

Mixed cryoglobulinemia is a systemic vasculitis described as a triad characterized by purpura, weakness and arthralgias. Since the first description of the disease in 1964 by Meltzer and Franklin our understanding of its pathogenesis has increased considerably. The striking association of the disease with hepatitis C virus infection was initially noted in 1990. Since then, the disease has gained growing attention among investigators involved in the study of autoimmune systemic disorders because it represents one of the most intriguing models of autoimmunity triggered by a virus. Nonetheless, a number of answered questions still remain to be resolved and are reviewed in this article.

bcl-2 and immunoglobulin gene rearrangement in patients with hepatitis C virus infection

An association between chronic hepatitis C virus (HCV) infection and clonal proliferation of B cells, including B cell lymphoma, has recently been demonstrated. However, the mechanism of malignant transformation is still unknown. It has been shown that B cells from patients with type II mixed cryoglobulinaemia (MC), strongly express the antiapoptotic bcl-2 oncogene product. Therefore, we investigated a possible mechanism of lymphomagenesis, the occurrence of bcl-2 and immunoglobulin gene rearrangement (IgH) in HCV-infected patients. Three groups of patients were studied: (1) 44 patients with HCV and MC (anti-HCV and HCV RNA positive); (2) 59 patients with chronic HCV infection without MC; (3) 50 patients with chronic liver disease (CLD) not related to HCV infection. The t(14;18) translocation (MBR bcl-2-JH) and IgH rearrangement (FR3/JH) were detected by polymerase chain reaction (PCR) in peripheral mononuclear cells. bcl-2 translocation was detected in 17/44 (39%), 7/59 (12%) and in none of the patients of groups 1, 2 and 3 respectively (P < 0.01). Monoclonal IgH rearrangement was detected in 15/44 (34%), 5/59 (8.5%) and 2/50 (4%) patients of groups 1, 2 and 3 respectively (P < 0.05). HCV-infected patients had a higher prevalence of monoclonal IgH rearrangement and bcl-2 translocation than patients with CLD of other aetiologies. These data suggest that HCV may play a role in the multistep mechanism of lymphomagenesis by inducing clonal proliferation of B cells and inhibition of apoptosis.

Pre-malignant and malignant lymphoproliferations in an HCV-infected type II mixed cryoglobulinemic patient are sequential phases of an antigen-driven pathological process

Type II mixed cryoglobulinemia (MC) is a systemic vasculitis characterized by the presence in the serum of a monoclonal cryoprecipitable IgM with rheumatoid factor (RF) activity. Hepatitis C virus (HCV) has been recognized as its major etiologic factor. Because MC frequently evolves into overt B-cell non-Hodgkin's lymphoma (NHL), chronic HCV infection is hypothesized to lead to both benign and malignant lymphoproliferative disease. In this study, we investigated mutations in the V(H) and V(K) genes of the B-cell clone originating the overt B-cell lymphoma in a subject with MC. Mutational patterns were analyzed longitudinally in two bone marrow biopsies obtained at the stage of MC, as well as in multiple involved tissues (bone marrow, liver, and peripheral blood cells) at the stage of overt NHL. Hybridization of variable-diversity-joining (VDJ) PCR products with a probe specific for the neoplastic clone indicated that the lymphoma originated from one of the clones over-stimulated during MC. This clone producing an IgM highly homologous to a protein with RF specificity may explain the MC syndrome in the patient. Moreover, the presence of an IgH ongoing mutation process and the expression of an Ig antigen receptor significantly homologous to an anti-HCV protein support the hypothesis that the MC syndrome and the subsequent evolution to NHL are antigen-driven lymphoproliferative processes possibly sustained by HCV. Furthermore, the marked reduction in intra-clonal diversity in the last bone marrow biopsy obtained at the stage of overt NHL points out a minor dependence of the cells on the antigen-driven mechanism, although an intrinsic propensity of the neoplastic cell to undergo replacement mutations cannot be excluded.

Replication status as a marker for predisposition for lymphoma in patients with chronic hepatitis C with and without cryoglobulinemia

OBJECTIVE

Essential mixed cryoglobulinemia (EMC) type II is associated with hepatitis C virus (HCV) in 90% of the patients with this disorder. A significant subset of these patients is at risk to develop non-Hodgkin lymphoma (NHL). The objective of this study was to examine whether the presence of EMC, a presumably premalignant step of lymphoproliferation, is associated with changes in the replication state of normal structural genes.

MATERIALS AND METHODS

The study group included three subgroups: (1) seven patients with HCV without EMC; (2) eight patients with HCV associated with EMC. 3. Seven patients with follicular lymphoma; and (3) six healthy individuals served as control group. Monocolor fluorescent in situ hybridization (FISH) with probes to p53, RB-1, and 21q22 was applied to leukocytes nuclei for the evaluation of replication timing.

RESULTS

Asynchronous replication (SD) rate was similar in patients with NHL and those with HCV associated with EMC and both are significantly higher when compared to patients with HCV without EMC and to normal controls (p < 0.01) for each comparison. This held true for all studied loci (21q22, RB-1, and p53). Patients infected by HCV (but without EMC) had a significantly higher rate of asynchronous pattern in comparison with healthy controls (p < 0.01).

CONCLUSIONS

Patients with a "premalignant" clinical condition HCV with EMC already demonstrate asynchronous type of replication which is similar to patients who already have an established malignant disease (i.e., NHL). In the future, replication may be used to assess the risk of malignant transformation in patients with "benign" proliferation.

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.

Lack of Fas and Fas-L mutations in patients with lymphoproliferative disorders associated with Sjögren's syndrome and type II mixed cryoglobulinemia

OBJECTIVE

Murine models (MRL/gld/gld mice) and recent evidence in humans suggest a possible role of Fas and Fas ligand (Fas-L) germline mutations in the pathogenesis of autoimmune-related lymphoproliferation, including adult cases. In this study, the presence of Fas and Fas-L germline mutations was investigated in a consecutive series of adult patients with lymphoproliferative disorders occurring in the context of Sjögren's syndrome (SS) and type II mixed cryoglobulinemia (MC).

METHODS

11 patients (8 primary SS and 3 type II MC; F/M: 10/1; mean age 64 yrs.) were investigated. All patients were suffering from atypical lymphoproliferative disorders or MALT lymphoproliferative lesions (mean duration 3.5 yrs.). Four patients later developed a malignant lymphoma. DNA from peripheral blood mononuclear cells from 11 patients and 10 controls was tested for germline mutations in the Fas gene (exons 4, 8 and 9) and Fas-L gene (exon 4) by the polymerase chain reaction-single strand conformation polymorphism (SSCP) method.

RESULTS

All DNA samples from both patients and controls showed amplification of Fas and Fas-L specific fragments. Identical SSCP migration patterns were observed in all the cases, indicating the lack of mutations in the whole series.

CONCLUSION

Although it cannot be excluded that Fas and Fas-L mutations might be present in exons different from those analyzed, our data do not support the hypothesis that germline mutations in these genes are responsible for a major subset of lymphoproliferative syndromes in adult patients with SS and type II MC. Additional studies would be worthwhile in SLE-related lymphoproliferation, which is, however, a subset of limited clinical relevance when considering all cases with autoimmune-related lymphoproliferation.

Familial primary cryofibrinogenemia

BACKGROUND

To our best knowledge this is the second case ever described of familial primary cryofibrinogenemia (CFG).

PATIENTS

A 29-year-old Moroccan female and two of her three children suffered from painful purpura, slow healing small ulcerations and edema of both feet during the winter season. Laboratory investigations revealed the presence of cryofibrinogen in their blood plasma. All three patients were otherwise healthy and no associated disease could be demonstrated.

CONCLUSIONS

The diagnosis of CFG has to be considered in patients with livedo reticularis, edema, painful purpura and slow healing ulcera after cold exposure. Cryofibrinogen-precipitates in the blood plasma have to be determined. Because secondary CFG occurs much more frequently than the primary form, it is important to rule out associated diseases through extensive physical examination and laboratory investigations. This communication also stresses the importance of a through family history of patients with CFG. An autosomal dominant mode of inheritance is supposed.

Clonal analysis of intrahepatic B cells from HCV-infected patients with and without mixed cryoglobulinemia

Clonal rearrangements of Ig heavy chain (IgH) genes and hepatitis C virus (HCV) genomic sequences were assayed on intrahepatic B lymphocytes isolated from HCV chronically infected patients with and without type II mixed cryoglobulinemia (MC). Liver tissue samples from eight patients with and nine without MC were subjected to routine histologic studies, immunophenotyping, and genotypic analysis including IgH V-D-J region gene rearrangements by PCR. RT-PCR, signal amplification by branched DNA assay, and in situ hybridization technique were used to detect and quantitate HCV RNA genomic sequences in selected B cells purified from each tissue sample. Although HCV infection of intrahepatic B cells was shown in all patients both with and without MC, frank B cell monoclonal and oligoclonal patterns were found in only three and four patients with MC, respectively. No monoclonal profile was seen in the noncryoglobulinemic patients, whereas an oligoclonal profile was demonstrated in four of them. No clonalities were shown in HCV-unrelated patients matched for age and severity of liver disease. No obvious difference in HCV genotype distribution was found in relation to the clonal expansion profile. Noncryoglobulinemic patients showing clonal expansion in liver tissue had higher titers of serum rheumatoid factor (RF). Spontaneous production of RF was shown in cell cultures of intrahepatic B cells, suggesting their persistent stimulation in vivo. These data indicate that HCV infection of B cells and B cell clonal expansions occur in the liver microenvironment and preferentially involve RF-producing cells.

Haplotype HLA-B8-DR3 confers susceptibility to hepatitis C virus-related mixed cryoglobulinemia

Our aim was to investigate whether host genetic factors are involved in the onset of hepatitis C virus (HCV)-related mixed cryoglobulinemia (MC). We studied 25 consecutive patients presenting with a full-blown clinical picture of MC by physical examination, blood chemistry, assessment of cryoglobulins and their composition, nonorgan-specific autoantibodies, antibodies to HCV, serum HCV RNA, and HLA polymorphism. Biopsies of liver, bone marrow, and minor salivary glands were also performed in a number of patients. HLA results were compared with those of normal controls and patients with chronic HCV infection without MC and negative for autoimmune phenomena (pathological controls). Type II MC was found in 14 of 25 patients (56%), and type III MC was found in the remaining 11 (44%). All patients were positive for antibodies to HCV and/or serum HCV RNA. HLA-B8 was found in 40% (10 of 25) of patients compared with 10. 1% (38 of 377) of normal controls (P = .00003, Pcorrected = .0005, relative risk [RR] 5.9) and 6.7% (2 of 30) of pathological controls (P = .007, Pcorrected = not significant). As for class II HLA molecules, only DR3 was significantly more frequent in MC patients (40%, 10 of 25) than in normal controls (15.1%, 57 of 377; P = .003, Pcorrected = .03, RR 3.7). Odds ratio (OR) for the risk of developing MC was calculated in patients positive for B8 and/or DR3, and the highest OR (8.2) was observed in individuals possessing both. The results suggest that the development of HCV-related MC is associated with HLA-B8 and DR3 markers.

Monoclonal lymphocyte proliferation and bcl-2 rearrangement in essential mixed cryoglobulinaemia

A patient with essential mixed cryoglobulinaemia (EMC) type II and hepatitis C virus (HCV) infection, in whom immunophenotypic and genotypic studies demonstrated a clonal proliferation of B lymphocytes, is described. Fluorescent in situ hybridization with probes to Ig heavy chain gene and to the oncogene bcl-2 demonstrated a translocation of bcl-2 to the immunoglobulin heavy chain locus on chromosome 14. A sharp rise in the level of the monoclonal IgM was associated with a second genetic aberration [t(8:22) (q24:q11)]. No other clinical evidence of disease progression could be demonstrated. Low grade lymphoproliferative disorder with typical cytogenetic abnormalities developed on the background of EMC and HCV. Clinical progression was associated with a second genetic abnormality involving the myc oncogene. It is possible that HCV chronic infection may indirectly influence oncogenes associated with lymphoma.

HLA expression in type II mixed cryoglobulinemia and chronic hepatitis C virus

OBJECTIVE

Hepatitis C virus infection is closely associated not only with hepatic damage, but also with mixed cryoglobulinemia (MC) and other autoimmune and lymphoproliferative disorders. Because HCV is both hepatotropic and lymphotropic, the aim of this study was to investigate whether the genetic background may influence the clinical pattern seen in different patients.

METHOD

Two groups of patients with HCV infection were studied: 16 with type II MC and 18 with chronic active hepatitis (CAH). 120 bone marrow donors were considered as the control group. In all patients HLA-A-B-C antigens were evaluated using the microlymphocytoxicity technique, and HLA-DR by the PCR-SSP method.

RESULTS

The frequency of the HLA antigens expressed was not precisely defined in the two groups. However, the HLA-B51 and B35 antigens, which are often correlated with autoimmune disorders, were highly expressed in the MC patients (31.2%) compared to the controls (6.9%) and to the CAH group (11%). Moreover, HLA-A9 with its split A24 were present in 50% of the MC patients. More interesting was the expression of the HLA-DR7 antigen, which was found only in the CAH group, suggesting that it may influence the specific liver involvement in HCV infections.

CONCLUSION

These findings indicate that the HLA system may play an important role in the clinical manifestations of HCV infection.

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.

[Mixed cryoglobulinemia and the hepatitis C virus]

Mixed cryoglobulinemia is a cryoprecipitable immune-complex mediated disease, in which cryoglobulins are type II and III of the immunochemical classification of Brouet. Essential mixed cryoglobulinemia, in opposition to secondary, is characterized by the absence of well-defined underlying disease and clinically it shows the classical triad of Meltzer and Franklin. Several reports point to the frequent, through various, liver involvement in essential-defined mixed cryoglobulinemia. Particularly, the clinical and biological evidence of liver disease is commonly soft, in spite of the common bioptic evidence of persistent or chronic active hepatitis. The problem about which comes first in this association had been widely investigated, including the possible pathogenetic role of hepatotropic viruses. Initially some studies focused attention on hepatitis B virus, but now its importance is de-emphasized because of critical epidemiological review, results of HBV-DNA in cryoprecipitates, electron microscopy data. The recent opportunity of diagnostic tests for hepatitis C virus gave proof of its great importance in apparently essential mixed cryoglobulinemia. In fact, many researches have found a variously high prevalence of anti HCV antibodies and HCV-RNA in serum and cryoprecipitates, with selective concentration in the latter. Alpha interferon treatment has been suggested as first choice drug in the management of HCV related cryoglobulinemia. The mechanism is postulated to be primarily due to its antiviral activity. Up to date optimal dose and treatment period needs to be established.

Autoimmune haemolysis and red cell autoantibodies with ABO blood group specificity

In order to study red cell autoantibodies with ABO specificity, the records of 4668 patients seen over 32 years were examined. Five group A patients had high thermal amplitude cold agglutinins showing anti-A, -A1 or -AI specificity; none had ever received blood or blood products. They presented as chronic cold haemagglutinin disease, autoimmune haemolytic anaemia or were discovered during investigation of pregnancy, carcinomatosis or anaemia. In vivo haemolysis was evident in all but the antenatal case; only the patient with autoimmune haemolytic anaemia required treatment, responding well to steroids. ABO-specific autoantibodies thus appear similar in reactions and clinical manifestations to autoantibodies in general.

Complete amino acid sequence of the variable regions of two highly related heavy and light chains of human IgG (SFL) and IgM (RIV) rheumatoid factors

The complete amino acid structure of the variable regions of two monoclonal human rheumatoid factors (RF), antibodies that bind to the Fc portion of IgG, is presented. Although these RFs are of different isotypes, IgG (SFL) and IgM (RIV), they are highly related. They probably derive from the same KIII light chain variable region used, but the heavy chains are derived from genes of the VHIII family that are probably evolutionarily related. An analysis of the level of somatic mutation reveals that antigen selection was probably involved in the maturation of these clones. These antibodies, although highly related, are not merely IgM to IgG switch variants which occurred independently in different individuals. Little is currently known about the structure of IgG RFs and this study indicates that the level of somatic mutation of SFL is similar to other autoantibodies or antiviral antibodies of the IgG isotype.

Cryoglobulinemia induced by a murine IgG3 rheumatoid factor: skin vasculitis and glomerulonephritis arise from distinct pathogenic mechanisms

MRL-lpr/lpr mice spontaneously develop a lupus-like syndrome characterized by immunopathological manifestations such as necrotizing vascular lesions of ear tips and severe glomerulonephritis. Similar skin vascular and glomerular lesions associated with cryoglobulinemia can be induced in normal mice by injection of a monoclonal antibody (mAb)--6-19 (gamma 3 heavy chain and kappa light chain), exhibiting both cryoglobulin and anti-IgG2a rheumatoid factor (RF) activities--derived from the MRL-lpr/lpr autoimmune mouse. To determine the role of RF and/or IgG3 Fc fragment-associated cryoglobulin activities in 6-19 mAb-induced tissue lesions, a 6-19-J558L hybrid mAb (gamma 3 heavy chain and lambda 1 light chain) was produced by fusion between the 6-19 hybridoma and the J558L myeloma. Here we report that the 6-19-J558L hybrid mAb, which loses the RF activity but retains the cryoglobulin activity, fails to induce skin vascular lesions. However, it is still able to provoke glomerular lesions identical to those caused by the 6-19 mAb. Further, we have observed that the depletion of the corresponding autoantigen, IgG2a, in mice by treatment with anti-IgM antisera from birth also prevents the development of skin but not glomerular lesions. Our results indicate that both RF and cryoglobulin activities of the 6-19 mAb are required for the development of skin vasculitis, but its cryoglobulin activity alone is sufficient to cause glomerular lesions. In addition, cDNA cloning and sequencing of the 6-19 mAb has revealed that the 6-19 kappa light chain variable region amino acid sequence is encoded in a germ-line configuration, suggesting that immunoglobulin variable region germ-line genes could contribute to the generation of pathogenic autoantibodies.

[Immunoglobulin and T-cell receptor gene rearrangements in patients with autoimmune diseases]

Immunoglobulin-(Ig-) and T-cell-receptor-(TcR-)gene rearrangements were investigated in peripheral blood lymphocytes (PBL) of patients with various autoimmune disorders. In patients with SLE there was no predominant Ig- or TcR-gene rearrangement. This was also true in patients with a long disease duration and with excessive hypergammaglobulinemia. These results lead us to suggest that B cells are activated polyclonally in these patients. In those cases, where predominantly rearranged Ig- or TcR-genes were found, the autoimmune disorder was associated with a low-grade non-Hodgkin lymphoma (NHL). This coherence of B-cell malignancy and autoimmunity was only found in patients with cryoglobulinemia (KG), cold agglutinin disease (KA), and hemolytic anemia (AIHA).