Hepatitis C virus (HCV) has been implicated as the major etiologic factor sustaining B-cell clonal expansion in type II mixed cryoglobulinemia (MC). A putative pathogenetic role of HCV in the development of MC-associated B-cell malignancies has also been speculated. We report for the first time the localization of HCV within a parotid non-Hodgkin's lymphoma (NHL) lesion in the course of HCV- related type II essential MC, an important step to implicate any infectious agent in the lymphomagenesis. Plus and minus strand HCV RNA was first demonstrated by polymerase chain reaction on the whole RNA from the lesion. Further immunohistochemical studies localized HCV c22 proteins in the residual ductal or acinar parotid structures, which also abnormally expressed HLA-DR antigens. Weak c22 signals were inconstantly detected in cells strictly confined around the residual epithelium, while all the remaining infiltrating cells in the parotid lesion stained c-22-negative. Staining for c33 and c100 HCV antigens was negative. In situ hybridization (ISH) studies again identified the residual parotid epithelial cells as the site of HCV infection and replication in the NHL lesion. Sialotropic viruses previously involved in lymphoproliferation, ie, Epstein-Barr virus and human herpesvirus-6, were absent in the same tissue lesion. According to the current models of B-cell lymphomagenesis, a role of HCV as an exogenous antigenic stimulus should be considered for NHL development in the present case, whereas malignant B cells do not appear permissive of active HCV replication. Further efforts would be worthwhile to clarify a role of HCV infection in the development of some B-cell malignancies.

Two commercial assays detecting the presence of Mycobacterium tuberculosis complex in clinical specimens by rRNA target amplification (Gen-Probe Amplified M. tuberculosis Direct Test [AMTD]) and PCR (Amplicor) were evaluated. The tests were applied to 327 digested, decontaminated respiratory specimens collected from 236 patients. Results were compared with those of acid-fast staining and culture. The combination of culture and clinical diagnosis was considered the "gold standard." A total of 60 specimens were collected from 27 patients with a diagnosis of pulmonary tuberculosis. Thirteen of these specimens were from patients receiving standard antituberculosis therapy and therefore were not included in the comparison. Of the remaining 47 specimens, 33 were smear positive, 40 were culture positive, 45 were AMTD positive, and 39 were Amplicor positive. After resolution of discrepant results, the overall sensitivities, specificities, and positive and negative predictive values were 77, 100, 100, and 95 for staining; 87, 100, 100, and 97.4 for culture; 95.9, 98.9, 94, and 99.2 for AMTD; and 85.4, 99.6, 97.9, and 97.1 for Amplicor, respectively. Agreement between AMTD and Amplicor assay results was 96.8%. It is concluded that although both nucleic acid amplification methods are rapid and specific for the detection of M. tuberculosis complex in respiratory specimens, AMTD appeared to be more sensitive than Amplicor.

. Mazzaro C, Panarello G, Tesio F, Santini G, Crovatto M, Mazzi G, Zorat F, Tulissi P, Pussini E, Baracetti S, Campanacci L, Pozzato G (Pordenone General Hospital, Pordenone; University of Trieste, School of Medicine, Trieste, Italy). Hepatitis C virus risk: a hepatitis C virus‐related syndrome. J Intern Med 2000 247: 535–545. Background. The association between mixed cryoglobulinemia (MC) and hepatitis C virus (HCV) infection has been recently described in many reports. Objective. The aim of this study was to evaluate the long‐term prognosis of hepatitis C virus‐positive patients affected by mixed cryoglobulinemia with or without kidney involvement. Patients. At total of 119 hepatitis C virus‐positive patients affected by mixed cryoglobulinemia were divided in two groups. Group A: mixed cryoglobulinemia without kidney involvement (103 cases); group B: mixed cryoglobulinemia with glomerulonephritis (GN) (16 cases). A further 37 patients affected by mesangio‐proliferative glomerulonephritis (MPGN) were evaluated as controls (group C). Methods. Anti‐hepatitis C virus antibodies were determined by commercial kits and hepatitis C virus‐RNA was detected by polymerase chain reaction (PCR) amplification of the 5′ untranslated region (5′UTR) of the virus. The hepatitis C virus genotype was determined according to Okamoto. Liver biopsy was performed in 62 patients, bone marrow biopsy in 65 patients, and kidney biopsy in all patients with proteinuria. Results. In group A, 46 patients (45%) were affected by chronic liver disease (CLD), 21 (20%) by low‐grade non‐Hodgkin’s lymphoma (NHL) and 16 (15%) by both diseases. All patients of group B were affected by type I membrano‐proliferative glomerulonephritis, 3 (19%) by chronic liver disease, 6 (37%) by low‐grade non‐Hodgkin’s lymphoma, and 7 (44%) by both diseases. Several genotypes of hepatitis C virus were found, but Type 1b was prevalent. In group C, no patient showed chronic liver disease or non‐Hodgkin’s lymphoma. Younger age, higher mean blood pressure, lower C4 serum level, and poorer survival significantly distinguished group B from group A. Survival rates at 5 years were: 87.4% for group A, 89.5% for group C, and 50.0% for group B. None of the patients of group B developed kidney failure requiring dialysis, whilst infections were the leading cause of death. Conclusions. In hepatitis C virus‐positive patients, the presence of mixed cryoglobulinemia associated with kidney involvement seems to indicate a new syndrome characterized by immune system impairment, lack of progression to kidney failure, and poor survival (hepatitis C virus‐Risk syndrome).

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A clonal expansion of peripheral blood mononuclear cells committed to IgM cryoprecipitating rheumatoid factor production has been demonstrated in hepatitis C virus (HCV)-associated mixed cryoglobulinemia (MC). To determine the role of HCV in B cell gene rearrangements we studied a series of 57 HCV-infected patients with and without MC. Clonal Ig gene rearrangements of both RNA and DNA were detected in 10 of the 13 patients with type II MC, 1 patient had gene rearrangement of the DNA only, and 2 had polyclonal patterns. 2 of the 17 patients with type III MC showed clonal rearrangement of both RNA and DNA, in 6 only the DNA was rearranged clonally and in 9 the patterns were completly normal. 14 of 27 patients with cryocrit <1% or without cryoglobulins had clonal DNA rearrangements without any in the RNA. These results suggest that clonal lesions in the DNA are related to HCV infection and that these changes antedate the appearance of mixed cryoglobulinemia.