Direct Immunofluorescence of Mechanobullous Epidermolysis Bullosa Acquisita, Porphyria Cutanea Tarda and Pseudoporphyria.

Mechanobullous epidermolysis bullosa acquisita (mEBA) can have a clinical presentation that is very similar to other blistering diseases, such as porphyria cutanea tarda (PCT) and pseudoporphyria. Direct immunofluorescence is an important feature in the diagnosis of mEBA, although features that overlap with PCT and pseudoporphyria have been reported. This retrospective observational study investigated whether direct immunofluorescence can discriminate mEBA from PCT and pseudoporphyria. Biopsies of 13 patients with mEBA, 10 with PCT and 10 with pseudoporphyria were included. In 7 cases of PCT and 4 of pseudoporphyria, direct immunofluorescence showed a pattern at the dermal-epidermal junction that appeared similar to the u-serrated pattern in mEBA. Vessel wall depositions were observed in all 3 diseases, but were more frequent and more intense in PCT and pseudoporphyria than in mEBA. Careful examination of direct immunofluorescence of mEBA vs. PCT and pseudoporphyria revealed different staining patterns, although overlapping features were present. Therefore, integrating all clinical and laboratory data is essential to differentiate between mEBA, PCT and pseudoporphyria.

Cutaneous Manifestations of Scleroderma and Scleroderma-Like Disorders: a Comprehensive Review.

Scleroderma refers to an autoimmune connective tissue fibrosing disease, including three different subsets: localized scleroderma, limited cutaneous systemic sclerosis, and diffuse cutaneous systemic sclerosis with divergent patterns of organ involvement, autoantibody profiles, management, and prognostic implications. Although systemic sclerosis is considered the disease prototype that causes cutaneous sclerosis, there are many other conditions that can mimic and be confused with SSc. They can be classified into immune-mediated/inflammatory, immune-mediated/inflammatory with abnormal deposit (mucinoses), genetic, drug-induced and toxic, metabolic, panniculitis/vascular, and (para)neoplastic disorders according to clinico-pathological and pathogenetic correlations. This article reviews the clinical presentation with emphasis on cutaneous disease, etiopathogenesis, diagnosis, and treatment options available for the different forms of scleroderma firstly and for scleroderma-like disorders, including scleromyxedema, scleredema, nephrogenic systemic fibrosis, eosinophilic fasciitis, chronic graft-versus-host disease, porphyria cutanea tarda, diabetic stiff-hand syndrome (diabetic cheiroartropathy), and other minor forms. This latter group of conditions, termed also scleroderma mimics, sclerodermiform diseases, or pseudosclerodermas, shares the common thread of skin thickening but presents with distinct cutaneous manifestations, skin histology, and systemic implications or disease associations, differentiating each entity from the others and from scleroderma. The lack of Raynaud's phenomenon, capillaroscopic abnormalities, or scleroderma-specific autoantibodies is also important diagnostic clues. As cutaneous involvement is the earliest, most frequent and characteristic manifestation of scleroderma and sclerodermoid disorders, dermatologists are often the first-line doctors who must be able to promptly recognize skin symptoms to provide the affected patient a correct diagnosis and appropriate management.

Estudo da imunofluorescência direta, imunomapeamento e microscopia ótica na porfiria cutânea tardia / Study of direct immunofluorescence, immunofluorescence mapping and light microscopy in porphyria cutanea tarda

FUNDAMENTO: Apesar de a porfiria cutânea tardia ser a mais frequente das porfirias, há poucos estudos que abordam sua fisiopatologia cutânea. OBJETIVO: Avaliar as alterações cutâneas na porfiria cutânea tardia utilizando a microscopia ótica e a imunofluorescência direta, antes e depois do tratamento com cloroquina. Realizar o imunomapeamento antigênico da bolha para estudo do seu nível de clivagem. MÉTODOS: Relata-se a microscopia ótica e imunofluorescência direta de 28 pacientes em três fases diferentes: 23 pacientes com porfiria ativa antes do tratamento (Fase A), sete pacientes com remissão clínica durante o tratamento (Fase B) e oito pacientes com remissão bioquímica (Fase C). O imunomapeamento foi realizado em sete pacientes. RESULTADOS: Na porfiria ativa, a imunofluorescência direta demonstrou fluorescência homogênea e intensa no interior e na parede dos vasos e na junção dermoepidérmica. Na remissão clínica (Fase B) e na remissão bioquímica (Fase C), o depósito de imunoglobulinas se manteve, mas o depósito de complemento apresentou diminuição na maioria. O imunomapeamento não demonstrou plano de clivagem fixo. CONCLUSÃO: Não houve correlação entre a resposta clínica e os depósitos de imunoglobulinas. A diminuição do complemento favorece a hipótese de que a ativação da cascata do complemento representa uma via adicional que leva à lesão endotelial.

BACKGROUND: Even though porphyria cutanea tarda is the most frequent type of porphyria, there are few studies about its cutaneous physiopathology. OBJECTIVE: To evaluate skin changes in porphyria cutanea tarda using light microscopy and direct immunofluorescence before and after treatment with chloroquine. To perform antigen immunomapping of bullae to study their level of cleavage. METHODS: Light microscopy and direct immunofluorescence of 28 patients are reported in three different phases: 23 patients with active porphyria before treatment (Phase A), 7 patients with clinical remission during treatment (Phase B), and 8 patients with biochemical remission (Phase C). Immunomapping was performed on 7 patients. RESULTS: In active porphyria, direct immunofluorescence showed homogenous and intense fluorescence on the inside and on the walls of blood vessels as well as in the dermal-epidermal junction. In clinical remission (Phase B) and biochemical remission (Phase C), the deposit of immunoglobulins was maintained, but the deposit of complement was reduced in most cases. Immunomapping revealed no standard cleavage plane. CONCLUSION: No correlation was observed between clinical response and immunoglobulin deposits. The reduction of complement favors the hypothesis that activation of the complement cascade represents an additional pathway that leads to endothelial damage.

Study of direct immunofluorescence, immunofluorescence mapping and light microscopy in porphyria cutanea tarda.

BACKGROUND: Even though porphyria cutanea tarda is the most frequent type of porphyria, there are few studies about its cutaneous physiopathology. OBJECTIVE: To evaluate skin changes in porphyria cutanea tarda using light microscopy and direct immunofluorescence before and after treatment with chloroquine. To perform antigen immunomapping of bullae to study their level of cleavage. METHODS: Light microscopy and direct immunofluorescence of 28 patients are reported in three different phases: 23 patients with active porphyria before treatment (Phase A), 7 patients with clinical remission during treatment (Phase B), and 8 patients with biochemical remission (Phase C). Immunomapping was performed on 7 patients. RESULTS: In active porphyria, direct immunofluorescence showed homogenous and intense fluorescence on the inside and on the walls of blood vessels as well as in the dermal-epidermal junction. In clinical remission (Phase B) and biochemical remission (Phase C), the deposit of immunoglobulins was maintained, but the deposit of complement was reduced in most cases. Immunomapping revealed no standard cleavage plane. CONCLUSION: No correlation was observed between clinical response and immunoglobulin deposits. The reduction of complement favors the hypothesis that activation of the complement cascade represents an additional pathway that leads to endothelial damage.

Mast cells and transforming growth factor-beta expression: a possible relationship in the development of porphyria cutanea tarda skin lesions.

BACKGROUND: Porphyria cutanea tarda (PCT) is a metabolic disease characterized by vesicles and blisters in sun-exposed areas and scleroderma-like lesions in sun-exposed and non-sun-exposed areas. Mast cells participate in the pathogenesis of bullous diseases and diseases that show sclerosis, including PCT. Moreover, transforming growth factor-beta (TGF-beta) is the main cytokine in the development of tissue sclerosis. The correlation of mast cells and TGF-beta with the lesions of PCT has not been examined, however. The possible role of mast cells and TGF-beta (and the relationship between them) in the development of PCT lesions is discussed. METHODS: To quantify mast cells and cells expressing TGF-beta in skin samples from patients with PCT and controls, immunohistochemical studies were performed in tissue sections allied to morphometric analyses. RESULTS: The numbers of mast cells and cells expressing TGF-beta per square millimeter were increased in the PCT group relative to controls, and there was a direct and significant correlation between the mast cell number and cells expressing TGF-beta in PCT. CONCLUSIONS: The results suggest that the increased number of mast cells and of cells expressing TGF-beta, as well as their direct correlation, may contribute to the pathogenesis of the skin lesions in PCT.

Cutaneous vascular deposition of C5b-9 and its role as a diagnostic adjunct in the setting of diabetes mellitus and porphyria cutanea tarda.

BACKGROUND: The cutaneous lesions of diabetes mellitus (DM) and porphyria cutanea tarda (PCT) exhibit distinctive microvascular changes including basement membrane zone thickening and lamellation, morphologically appearing as hyaline-like alterations of the vessel wall. Immunofluorescence demonstrates homogeneous mantles of immunoglobulin in the microvasculature. The staining intensity is variable and in some cases can closely approximate those immunofluorescent changes seen in photoaged skin. OBJECTIVE: The purpose of this study was to establish an association between the microvascular changes seen in the skin from patients with DM and PCT and the presence of C5b-9 deposition, potentially defining the C5b-9 assay as an additional diagnostic adjunct. METHODS: Routine light microscopy and immunofluorescence studies were conducted on skin biopsy specimens from 14 patients with cutaneous manifestations of DM and 17 patients with PCT. The immunofluorescence profile included IgG, IgM, IgA, C3, C3d, C4d, and C5b-9. RESULTS: Fourteen of 14 DM and 17 of 17 PCT skin biopsy specimens revealed extensive granular and homogeneous vascular deposition of C5b-9; a similar pattern was observed for C3d and C4d. Control specimens from patients without DM and PCT, where C5b-9 was not an expected immunoreactant, were negative. Positive controls were cases of vasculitis, scleroderma, and dermatomyositis without DM and PCT where C5b-9 deposition was expected. C5b-9 deposition was observed and was of lesser magnitude than that encountered in patients with PCT or DM. LIMITATIONS: We were unable to obtain detailed clinical information on some of the diabetic patients in regards to significant extracutaneous vascular complications. In addition, a correlation between hemoglobin 1 Ac levels and the extent of C5b-9 deposition could not be ascertained as the serum levels for hemoglobin 1 Ac were unknown. CONCLUSION: Granular and homogeneous deposits of C5b-9 in vessels, along with homogeneous deposits of immunoglobulin within the blood vessels, are characteristic immunofluorescence findings in patients with DM and PCT. In regards to potential mechanisms of C5b-9 deposition, decreased metabolism of C5b-9 due to glycosylation of CD59 in the setting of DM and activation of complement by irradiated porphyrins in PCT are proposed. The extent of C5b-9 deposition suggests that this complex may play a pathogenetic role in the evolution of microvascular injury in patients with DM and PCT.

Extrahepatic manifestations of Hepatitis C Virus infection: a general overview and guidelines for a clinical approach.

Hepatitis C Virus is associated with a wide series of extrahepatic manifestations. Based on available data the link between the virus and some of these extrahepatic diseases is only suggested and needs further confirmation. Hepatitis C Virus-related lymphoproliferative disorders, whose prototype is mixed cryoglobulinaemia, represent the most closely related extrahepatic manifestations of Hepatitis C Virus. Other Hepatitis C Virus-associated disorders include nephropathies, thyreopathies, sicca syndrome, idiopathic pulmonary fibrosis, porphyria cutanea tarda, lichen planus, diabetes, chronic polyarthritis, cardiopathy and atherosclerosis. A pathogenetic link between Hepatitis C Virus and some extrahepatic manifestations was confirmed by their responsiveness to antiviral therapy, which is now deemed the first therapeutic option to consider. By contrast, there are diseases where treatment with interferon was ineffective or dangerous. The aim of the present paper is to outline the most recent evidence concerning extrahepatic disorders that are possibly associated with Hepatitis C Virus infection. Special emphasis will be given to discussion of the most appropriate clinical approaches to be adopted in order to diagnose, treat (possibly prevent) and follow-up extrahepathic diseases in patients with Hepatitis C Virus infection.

Autoantibodies in sporadic porphyria cutanea tarda.

In an investigation of autoimmune antibodies using indirect immunofluorescence and Western blot analysis in a group of porphyria cutanea tarda patients we did not find any cytosolic antibodies potentially able to inhibit uroporphyrinogen decarboxylase. Furthermore, no known etiological factors were present in any of our patients. We therefore consider the development of the recently reported autoantibody with a molecular weight of 40 kDa a reaction to infection with the hepatitis C virus. The origin of mostly antinuclear antibodies against liver antigens (50, 45 and 56 kDa), detected in seven patients, was not identified and their etiopathogenetic implications remain unknown.

Autoimmunity and HCV infection in porphyria cutanea tarda: a controlled study.

Autoimmunity and high rates of autoantibodies have been implicated in the pathogenesis of porphyria cutanea tarda. These abnormalities could be in part virus-induced, since porphyria cutanea tarda in most geographical regions is highly associated with hepatitis C virus infection. We analyzed the link of autoantibodies, autoimmune hepatitis and systemic lupus erythematosus in 111 patients with porphyria cutanea tarda and sex- and age-matched controls (mean age 58+/-13 years) in Germany, a region with a low prevalence of hepatitis C virus infection. Patients with porphyria cutanea tarda displayed lower rates of anti-nuclear antibodies (16/111, 14% vs 28/111, 25%, p<0,05) and of antibodies against smooth muscle (25/111, 23% vs 48/111, 43%, p<0,01), than controls. The percentage of patients with porphyria cutanea tarda with positive anti-HCV was low but significantly higher than in our controls (9/111, 8% vs 0/111, 0%, respectively), (p<0,05). Two patients with porphyria cutanea tarda (2/111, 2%) fulfilled the criteria for systemic lupus erythematosus and not one of 65 patients was found to have clinical autoimmune hepatitis. In the first controlled study of a large cohort of patients with porphyria cutanea tarda no increased prevalence of selected autoantibodies and autoimmune hepatitis was found. However, a higher prevalence of HCV infection and systemic lupus erythematosus in patients with porphyria cutanea tarda was confirmed.

Autoantibodies to human cytosol: a marker of sporadic porphyria cutanea tarda.

The enzymes potentially involved in the pathogenesis of sporadic porphyria cutanea tarda (PCT) reside in liver cytosoles and microsomes. PCT is frequently associated with hepatitis C virus (HCV) infection, which is in turn associated with autoimmune manifestations. To investigate whether autoimmune reactions, possibly triggered by HCV, are involved in the pathogenesis of PCT, we measured by immunoblot autoantibodies to human cytosolic and microsomal liver fractions in 82 patients with PCT (77% with HCV infection), 105 with other liver disorders and 40 healthy subjects. Anti-liver cytosolic antibodies were more frequent in PCT patients (38/82, 46%) than in pathological controls (P < 0.05-P < 0.001) or in healthy subjects (3/40, 8%, P < 0.001). Among PCT patients, anticytosolic antibodies were more frequent in HCV positive (36/63, 57%) than in HCV negative (2/19, 11%, P < 0.05) cases. Reactivity to a 40-kDa cytosolic polypeptide was present in 20 PCT patients (19 HCV positive), being more frequent than in all pathological controls (P < 0.01-P < 0.0001). Histological activity index (P = 0.04) and antibodies to HCV (P = 0.027) - but not HCV RNA - were associated independently with anticytosolic antibodies as assessed by multivariate analysis. In contrast, frequency of antiliver microsomal antibodies was similar in PCT patients (24/82, 29%) and pathological controls (8-26%), being higher in the autoimmune hepatitis control group (23/23, 100%, P < 0.0001). In conclusion, anticytosolic antibodies, particularly to a 40-kDa polypeptide, are frequent in PCT and associated with HCV infection and severity of liver damage.

[Extrahepatic manifestations in hepatitis C. Are they overlooked?]. / Ekstrahepatiske manifestasjoner ved hepatitt C-infeksjon. Blir de oversett?

BACKGROUND: There are accumulating documentation of autoimmune mediated extrahepatic manifestations of hepatitis C virus infection. The virus is hepatotrophic and lymphotrophic. It mutates frequently with subsequent inadequate immune response and chronic stimulation of T and B cells. This may be one explanation for the increased frequency of the autoimmune diseases associated with hepatitis C virus infection. MATERIAL AND METHODS: In this review of the literature published in the period of 1990 to 2000, we present the most common extrahepatic manifestations of the hepatitis C virus infection. RESULTS: Mixed cryoglobulinaemia, membranoproliferative glomerulonephritis and membranous glomerulonephritis are highly associated with hepatitis C infection. Other autoimmune diseases may also be associated with hepatitis C infection, but further documentation is necessary. INTERPRETATION: Extrahepatic manifestations of hepatitis C virus infection are associated with several autoimmune diseases. When diagnosing an autoimmune disease, a test for a coinfection of hepatitis C is highly recommended. Antiviral therapy with interferon may in some cases reduce the activity of the autoimmune disease.

Autoimmunity and extrahepatic manifestations in hepatitis C virus infection.

Hepatitis C virus (HCV) infection is associated with various extrahepatic manifestations: mixed cryoglobulinaemia, membranoproliferative glomerulonephritis and, in southern Europe, to some extent with porphyria cutanea tarda. The association of haplotype HLA B-8 and DR-3 mixed cryoglobulinaemia and HCV infection has recently been demonstrated. Interferon alpha therapy decreases hepatitis C viraemia and improves the clinical signs and biochemical abnormalities of cryoglobulinaemia. There seems to be a south-north gradient in the prevalence of HCV-associated cryoglobulinaemia. The rare combination of hepatitis C and panarteritis nodosa has still not been confirmed. The sicca syndrome also seems to be associated with hepatitis C virus, but this is not the typical Sjögren syndrome. Existing studies have not answered the question of whether HCV plays a pathogenic role in the development of thyroid dysfunction and autoimmune thyroiditis. There seems to be a genetic predisposition for the manifestations of thyroid disease in the case of hepatitis C infection and interferon therapy. This predominantly affects women with haplotype HLA DR-3. Before beginning interferon therapy, these patients often show thyroid autoantibodies against the thyroid peroxidase and/or thyroglobulin. It is still unclear whether the rare combination of hepatitis C with aplastic anaemia and lymphoma has pathogenic aspects. These haematological manifestations are thought to be induced by the infection of haematopoietic cells with the hepatitis C virus. In rare cases, a stimulated HCV-induced interferon gamma synthesis by haematopoietic stem cells has been shown. Although an epidemiological association of hepatitis C with lichen planus, neuropathies and other diseases has been observed, the aetiological role and the pathogenic involvement of the hepatitis C infection remains unclear. Furthermore, the question of whether these extrahepatic diseases are autoimmune has not been clarified. On the other hand, a number of autoantibodies may be observed during the course of hepatitis C. Of particular interest are liver/kidney microsomal antibodies (LKM). Their occurrence in viral hepatitis may indicate an increased risk for treatment with interferons. In the clinical setting, the presence of these diseases should suggest hepatitis C infection and hepatitis C antibodies should be tested and, if positive, hepatitis C-RNA is indicated. If there is any evidence of an aetiological association of replicative hepatitis C infection and the above-mentioned extrahepatic diseases, antiviral treatment should be considered.

Hepatitis C virus in patients with porphyria cutanea tarda: relationship to HCV-genotypes.

Porphyria cutanea tarda (PCT) is a rare metabolic disorder characterized by an abnormal porphyrin metabolism and typical cutaneous lesions. Recently a strong association between PCT and hepatitis C virus (HCV) has been proposed. Studies in south Europe have shown high prevalence (53 to 91%) of HCV markers in patients with PCT. We studied HCV genotypes in 72 subjects: 40 with PCT and 32 patients with chronic liver disease. A high rate of HCV-RNA positive PCT patients (84%) was observed, reflecting an active HCV replication, the genotypes study showed a prevalence of genotype 1b in PCT patients (61.2%). These findings implicate HCV in the aetiology of PCT-associated liver disease suggesting that hepatitis C serological and virological testing could be indicated in all patients with PCT.

Porphyria cutanea tarda, hepatitis C, and HFE gene mutations in North America.

In some, but not all countries, porphyria cutanea tarda (PCT) has been associated with chronic infection with the hepatitis C virus (HCV). Recently, PCT has also been associated with mutations in the HFE gene that are associated with HLA-linked hereditary hemochromatosis. Until now, few studies of these associations have been reported from North America. The aims of this study were: 1) to assess the prevalence of HCV infection and HFE mutations in North American patients with PCT; 2) to compare demographic and laboratory features between those who are HCV-positive and HCV-negative; and 3) to study urinary porphyrin excretions in American HCV-positive patients without clinically manifest PCT. Clinical and laboratory data, including tests for HCV and urinary porphyrins, were collected from 70 unselected patients with typical PCT. Urinary porphyrins were also measured in 110 non-PCT patients with chronic hepatitis C. Mutational analyses of the HFE gene were performed in 26 PCT patients. Thirty-nine of 70 (56%) of the PCT patients had evidence of HCV infection. Thirty-two of 39 PCT patients with HCV were men, all of whom used alcohol. In contrast, 22 of 31 PCT patients without HCV infection were women, 12 of whom had taken estrogens. The HCV-positive group was more likely to have used illicit intravenous drugs (45% vs. 0%; P = 0.01), to have had several (>4) sex partners (48% vs. 13%; P = 0.005), and less likely to have no known risk factors for HCV infection (33% vs. 78%; P = 0.004). Total urinary porphyrin excretion was the same in the two groups, but those with HCV infection had a significantly lower percentage of uroporphyrin and higher percentages of hepta-and hexa-carboxy porphyrins in urine. Sixteen of 110 (15%) HCV-positive subjects without PCT had increased urinary porphyrins, but, unlike PCT, these were mainly coproporphyrin. Forty-two percent of PCT patients carried the C282Y mutation of HFE (15% homozygous), and another 31% carried the H63D mutation (8% homozygous). Thus, 73% of PCT patients had one of these mutations. The prevalence of HCV infection (56%) and mutations in the HFE gene (73%) are high among North American patients with PCT. Alcohol and estrogen use are important additional risk factors. All PCT patients should be tested for HCV infection and for HFE gene mutations. Although HCV infection is a trigger for PCT, preclinical PCT is rare in chronic HCV hepatitis C in the United States.

[Porphyria cutanea tarda and hepatitis C virus infection]. / Porphyria cutanea tarda og Hepatitis C virus-infektion.

Porphyria cutanea tarda (PCT) is a rare metabolic disorder characterized by an abnormal porphyrin metabolism and typical cutaneous lesions. Recently a strong association between PCT and hepatitis C virus (HCV) has been proposed. Studies in the south of Europe have shown high prevalences (53 to 91%) of HCV markers in patients with sporadic PCT. Six characteristic case stories are presented. We suggest routine hepatitis C serological testing in all patients with PCT, as HCV infection is a major predisposing factor for the disease.

[Hepatitis C virus infection in patients with porphyria]. / Infección por virus C de la hepatitis en pacientes con porfiria.

Hepatitis C virus antibodies were studied in sera coming from 39 patients with porphyria (cutanea tarda in 17, variegate in 8, intermittent acute in 4, coproporphyria in 2 and protoporphyria in 8). Nine of 17 patients with porphyria cutanea tarda had positive antibodies, but none of the patients with other types of porphyria. All subjects with porphyria cutanea tarda had histological or laboratory liver abnormalities. There was no relationship between the presence of antibodies and frequency of alcoholism, diabetes, or carbohydrate intolerance. Family background of porphyria was significantly less frequent among patients with positive hepatitis C virus antibodies. In 13 patients, a liver biopsy was performed, always showing signs of chronic hepatitis, whose magnitude was higher in those with positive antibodies. It is concluded that, as reported previously, hepatitis C virus may be an activating factor for porphyria cutanea tarda or may potentiate its accompanying liver disease.

Hepatitis C virus-related autoimmunity in patients with porphyria cutanea tarda.

Hepatitis C virus (HCV) infection is frequently found in autoimmune hepatitis and mixed cryoglobulinaemia. In these conditions HCV could be responsible for immuno-mediated organ alterations. The aim of this study was to evaluate the presence of immunological alterations in PCT patients, in which HCV infection has been frequently found. Twenty-three PCT patients were evaluated for clinical and serological alterations, including: chronic hepatitis, other systemic symptoms, serum cryoglobulins and rheumatoid factor (RF), haemolytic complement, serum immunoglobulins, anti-nuclear (ANA), anti-smooth muscle (ASMA), anti-liver-kidney-microsomal (anti-LKM1), anti-soluble-liver-antigen (SLA), anti-mitochondrial (AMA), anti-GOR antibodies, anti-HCV and HCV RNA. Abnormal serum ALT were present in the majority of cases (20/23, 87%), while liver biopsy revealed a chronic persistent hepatitis or chronic active hepatitis in 15/20 (75%) PCT patients. In a high percentage of subjects (91%) the presence of anti-HCV was detected by ELISA and RIBA II (Chiron, Emeryville CA, USA). In 17/22 (77%) cases the ongoing HCV replication in the serum was demonstrated by the detection of HCV genomes (polymerase chain reaction). The prevalence of both anti-HCV and HCV RNA in PCT was significantly higher if compared to 22 systemic immunological diseases (P < 0.001) and 47 healthy subjects (P < 0.001). A possible HCV-induced autoimmunity in PCT was suggested by the presence of the following immunological parameter alterations: anti-GOR in 13/23 (57%), ANA in 4/23 (17%), ASMA in 18/23 (78%), anti-LKM1 in 1/23 (4%), RF in 23/23 (100%), mixed cryoglobulins in 4/23 (17%), complement consumption in 10/23 (43%).(ABSTRACT TRUNCATED AT 250 WORDS)