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Biomedical subjects

F Bartolomeo

Publications and source records attributed to F Bartolomeo.

10 recordsLinked to original sources

Long term effects of cryoapheresis and cytostatic treatment in essential mixed cryoglobulinemia.

We studied the effects of cryoapheresis combined with different immunosuppressive treatments on the course of the glomerulonephritis of essential mixed cryoglobulinemia. The study was carried out on 11 patients. The effects of immunosuppressive treatments on cryoglobulin rebound after cryoapheresis varied widely. In those responding with sustained reduction in serum cryoglobulin levels, creatinine clearance increased, an effect that lasted several years in 4 patients. In one patient cryoglobulin disappeared, with almost fully recovery of renal function and normalization of blood pressure. One patient died of acute liver failure shortly after the first observation and another entered regular dialysis treatment. All the other patients are still alive after follow-up of 2-9 years. These results compare favourably with those reported by other investigators and suggest that cryoapheresis and cytostatic drugs are beneficial for glomerulonephritis associated with essential mixed cryoglobulinemia.

Adult↗

Glomerular deposits of rheumatoid factor in glomerulonephritis.

One hundred and forty-four kidney biopsy specimens with various forms of glomerulonephritis were studied to assess the presence of Rheumatoid Factor (RF) deposits. RF deposits were found in 21 specimens: six with acute post-streptococcal glomerulonephritis, two with crescentic glomerulonephritis, four with lupus nephritis, eight with essential mixed cryoglobulinaemia glomerulonephritis, and one with end-stage kidney disease. Blocking and elution studies carried out on specimens with essential mixed cryoglobulinaemia provided evidence that the RF deposits derive from circulating monoclonal RF. This data suggests that RF participates in the formation of glomerular immune deposits in several forms of immune complex mediated glomerulonephritis.

Biopsy↗

Suppression of post-apheresis autoantibody rebound in cryoglobulinemia and cold agglutinin hemolytic anemia.

We studied the effect of immunosuppressive treatment on the autoantibody rebound that follows autoantibody withdrawal accomplished by extracorporeal plasma treatment. The study was carried out on 9 patients, 8 having essential mixed cryoglobulinemia and 1 cold agglutinin hemolytic anemia. As immunosuppressive drugs we used either cyclophosphamide and prednisolone or arabinoside C and cyclophosphamide. The effect of immunosuppressive treatment on autoantibody rebound (Igm anti-IgG; IgM cold agglutinins) varied widely, a suppressive effect of varying degree having been observed in about half the cases treated with either drug regimen.

Anemia, Hemolytic, Autoimmune↗

Glomerular localization of circulating antiglobulin activity in essential mixed cryoglobulinemia with glomerulonephritis.

Kidney biopsy samples from 27 patients with essential mixed cryoglobulinemia of the IgG-IgM(k) type and glomerulonephritis were studied to assess whether glomerular immunodeposits display antiglobulin (AG) activity similar to that of serum cryo-IgM. A preparation of heat-aggregated human IgG (FAIgG) was used to search for tissue AG activity, and blocking tests and reactivity tests were carried out to define the nature of this activity. Glomerular localization of FAIgG was observed in 17 out of 27 kidney specimens, the positive findings being always associated with IgM deposits. Prior exposure of tissue sections to anti-IgM serum blocked the FAIgG reaction, but no such effect was produced by the pretreatment with other antisera. The positive FAIgG tissue specimens yielded a similar fluorescence pattern with aggregated alkylated-reduced IgG, but did not react at all with the aggregated F(ab')2 or aggregated albumin. The IgM recovered in the eluate of a kidney biopsy specimen displayed AG activity. Patients with AG deposits showed more severe histologic changes and a greater renal functional impairment than did those without. The data support the notion that circulating cryo-IgM anti-IgG participates in the formation of glomerular immunodeposits and in the genesis of renal damage.

Adult↗

HBsAg glomerular deposits in glomerulonephritis: fact or artifact?

To evaluate the role of the hepatitis B virus infection in the pathogenesis of glomerulonephritis, we screened 136 consecutive patients with various types of glomerular lesions for the presence of HBsAg either in serum or in kidney biopsy specimens by means of radioimmunoassay and direct immunofluorescence technique, respectively. In selected patients, we carried out the search for antiglobulin activity (AA) factor(s) within the renal tissue with a fluoresceinated aggregated human IgG preparation (FITC-IgGagg). Eleven HbsAg seropositive patients were found, none of whom showed HBsAg deposits within their kidney biopsy specimen. Five of the remaining 125 seronegative patients, 3 with mixed cryoglobulinemia and 2 with lupus nephritis, showed glomerular-positive staining with a rabbit fluoresceinated anti-HBs serum and deposits of IgM endowed with AA, along with IgG and complement factors. The presence of HBsAg within the glomeruli was not confirmed, however, when a fluoresceinated anti-HBs Fab' preparation was used instead of the fluoresceinated anti-HBs serum. The pretreatment of the tissue sections with unconjugated anti-IgM serum blocked the direct staining for HBsAg and FITC-IgGagg, but not that of the other immunoreactants. Conclusion. The IgM AA deposits may interfere with the direct immunofluorescence testing for HBsAg, leading to erroneous interpretation.

Antigen-Antibody Complex↗

HBsAg immune complex glomerulonephritis.

Out of 97 patients with various forms of glomerulonephritis 10 were found to be HBsAg seropositive. None of these showed HBsAg immunodeposits within the kidney. Direct immunofluorescent kidney staining for HBsAg was observed in 4 out of 87 HBsAg seronegative patients. The HBsAg staining in kidneys was a false positive reaction due to binding of the Fc portion of the fluoresceinated IgG molecules to the IgM RF tissue deposits. The false positive reaction for HBsAg is not revealed by the usual specificity controls for fluorescence staining. The role of HBsAg in glomerulonephritis remains unproven.

Antigen-Antibody Complex↗

Selective removal of plasma cryoglobulins in cryoglobulinaemia.

Cryoglobulins were removed from the plasma of two patients with mixed cryoglobulinaemia (IgM(k)-IgG type) associated with severe membrano-proliferative glomerulonephritis and angiitis. The removal of about half the circulating cryo-Igs ('cryo-Igpheresis') was followed by a brisk rebound in cryo-Igs due to the rapid synthesis rate of monoclonal IgM(k) with anti-IgG activity. 'Cryo-Igpheresis' + cyclophosphamide treatment suppressed the rebound of cryo-IgGs, but not that of the cryo-IgMs. This differential effect was due to decrease of the antibody activity of cryo-IgMs. The clinical implications of such changes need further evaluation.

Cryoglobulins↗