Browsing by Author "KUNICK, M"

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    A STUDY ON THE ANTIGENIC NATURE OF CIRCULATING IMMUNE-COMPLEXES IN HEMOLYTIC-UREMIC SYNDROME - NO EVIDENCE OF PLATELET MEMBRANE GLYCOPROTEIN ANTIGENS
    (KARGER, 1994) OLAVARRIA, F; PEREIRA, J; MEZZANO, S; KUNICK, M; CASTILLO, A
    Circulating immune complexes (CIC) have been described in the hemolytic uremic syndrome (HUS) in children. They may represent an epiphenomenon or could be related to the platelet activation and endothelial damage observed in this disease. In an attempt to define this relationship, we investigated the CIC isolated in 17 patients with the classic form of HUS, by means of monoclonal antibodies against platelet surface glycoprotein Ib and IIb-IIIa complex. The negative results obtained do not support the possibility of platelet antigens being constituents of CIC and make an antibody-induced platelet activation in HUS very unlikely.
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    DECREASED PLATELET COUNTS AND DECREASED PLATELET SEROTONIN IN POSTSTREPTOCOCCAL NEPHRITIS
    (KARGER, 1995) MEZZANO, S; KUNICK, M; OLAVARRIA, F; ARDILES, L; ARANDA, E; MEZZANO, D
    Mean platelet survival time in patients with acute poststreptococcal glomerulo-nephritis (APSGN) is reduced to 50-60% of the control values, and glomerular deposits of platelet factor 4 are found in these patients. In order to investigate further systemic platelet changes of pathogenic, clinical or prognostic significance, we measured the platelet serotonin (5-HT) content and the blood platelet counts during the Ist week of the disease in 27 patients with APSGN. Platelet 5-HT was significantly reduced in patients with APSGN as compared with patients with impetigo without glomerular involvement (785+/-54 vs. 1,329+/-94 ng 5-HT/10(9) platelets; p<0.001). Similarly, the mean blood platelet count was reduced to 247+/-16x10(3) as compared with 303+/-14x10(3) in the controls (p<0.05). Thirteen (48%) of these patients had individual values of platelet 5-HT lower than the 95% confidence interval calculated in the control group. No significant correlation was observed between the concentration of 5-HT and either the severity of the disease judged by the amount of urinary protein excretion and the serum creatinine value or the presence of circulating immune complexes. Significant correction of the platelet 5-HT content (to 1,180+/-111 ng/10(9) platelets; p<0.01) and of the platelet counts (to 309+/-21x10(3); p<0.01) were observed in the longitudinal study at least 2 weeks later. Platelet activation, with secretion of granular content and increased consumption, may explain these findings. Additionally, the reduced mean age of the circulating platelets could contribute to their decreased 5-HT levels. The reduced platelet counts are not of clinical significance, but serial measurements of platelet 5-HT may be useful in predicting active glomerular inflammation.