HCV and monoclonal gammopathies.

OBJECTIVE: To determine the prevalence of antibodies against HCV in monoclonal gammopathies with and without cryoglobulinemic activity. METHODS: 201 patients were divided into two groups: (I) 94 patients with monoclonal gammopathies with cryoglobulinemic activity, and (II) 107 with monoclonal gammopathies without cryoglobulinemic activity. Cryoglobulins were characterized by immunofixation; HCVAb were detected using second-generation ELISA and RIBA methods; in 38 cases the presence of HCV in peripheral blood mononuclear cells was evaluated by PCR. RESULTS: The HCVAb prevalence, as evaluated by RIBA, in Group I was 69.1% while in Group II it was only 14.9%. Histological and immunohistochemical study of the bone marrow in Group I patients frequently showed signs of nodular B-cell clonal expansion. CONCLUSIONS: Our data confirm the existence of a close correlation between HCV infection and the monoclonal gammopathies with cryoglobulinemic activity. HCV-positive cryoglobulinemic is characterized by self-limiting IgM monoclonal expansion associated with histological aspects of bone marrow lymphoid nodules that do not expand in the course of the disease like classic evolving lymphoproliferative processes.

Characterization of cryoglobulins: some remarks on methodology.

OBJECTIVE: The experience of our group in the characterization of the cryoglobulins during the last 8 years is reported, and the possible advantages of immunofixation versus immunoblotting are discussed. METHODS: 25 out of 171 cryoprecipitates studied by immunofixation were also examined by immunoblotting, a technique which has been suggested to offer advantages in analysing monoclonal components. RESULTS: We confirm that immunofixation may be the technique of choice given its easier execution and interpretation, better standardization, and lower overall cost.

Cryoglobulinemia in HCVAb+ patients on chronic hemodialysis.

OBJECTIVE: Striking evidence of HCV infection has been found in mixed cryoglobulinemia (MC) and HCV has been hypothesized to be the causative agent of this disease. To assess the association of C virus infection and cryoglobulinemia we studied cryoglobulin levels in 66 patients on maintenance hemodyalisis who were selected on the basis of HCVAb positivity and not because they were affected by liver disease. The control group was made up of 45 patients also on hemodyalisis but without HCV infection. RESULTS: Circulating cryoglobulins were found in 34 (52%) of 66 HCV+ patients: the cryocrit was < 1% in 20, 1 to 5% in 12, and > 5% in 2 patients. The cryoglobulins were classified by immunofixation as type II in 8 and type III in 8 others; identification was not possible in 18 cases. In the HCVAb- control group untypable cryoglobulins were detected in 9% of the patients at < 1% by volume. No correlation was found between these data and the liver disease detected by biohumoral tests. CONCLUSIONS: Our data confirm the close link between HCV infection and cryoglobulins; the prevalence of circulating cryoglobulins in uremic HCVAb+ patients is very close to that found in HCV-related liver disease.

Hemifield pattern-reversal visual evoked potentials (VEPs) in retrochiasmal lesions with homonymous visual field defect.

This study was designed to examine the clinical significance and the reliability of hemifield pattern reversal VEPs in the assessment of homonymous visual field defects due to retrochiasmal lesions. 13 patients with traumatic, neoplastic or ischemic lesions of the cerebral parenchyma, and 18 normal subjects were studied. The results show that amplitude asymmetries over 4 microV (between responses evoked by right and left hemifield stimulation, recorded ipsilaterally to the stimulated hemifield) are clinically relevant for hemianopic visual field defect. Significant correlations were found between the VEP features and the site of the damage: lesions of the occipital cortex were generally found to cause more pronounced bioelectrical abnormalities than those due to lesions affecting the visual pathways, with cortical sparing.

Serum growth-promoting activity measured as [3H]thymidine incorporation into human activated lymphocytes and serum transferrin levels in newborns and mothers.

Serum growth-promoting activity measured as [3H]thymidine incorporation into human activated lymphocytes and serum transferrin levels were measured during the perinatal period in newborns and mothers. Both thymidine activity (TA) and transferrin levels were significantly increased at the time of delivery in mothers compared to control women, and there was a progressive return to control levels in the first 5 postpartum days. A significant correlation was found between TA and placental weight. In the newborns, TA was low in cord blood after vaginal delivery but not in the cord blood from babies born by cesarean section. In premature newborns, TA was lower than in full term newborns. In all newborns during the first 24 postnatal hours, there was an increase in TA with levels rising above adult control values: levels in cord blood were positively correlated with birth weight but not with thymidine activity. These data afford complementary insights into the humoral controls of growth in newborn infants.