Allo and auto-antibodies against platelet antigens: a new immunoenzymatic assay for their detection and quantitation.

A new immunoenzymatic assay for the detection of serum-free and platelet-associated (PA) antibodies is described. This method evidences the platelet bound IgG employing the biotin-avidin system. Following a common sensitization step, the PA-IgG can be directly detected on the cell membranes, and their amount can be evaluated by an anti-globulin consumption assay. In comparison with the platelet suspension immunofluorescence test (PSIFT), the ELISA assay is a little less specific but it is more sensitive: less than 1 ng/ml of IgG can be detected. The number of IgG molecules/platelet detected investigating normal and pathological sera is higher than that reported by others: such results are probably related to the nonhomogeneity of immunoglobulins implicated in the assay.

Neonatal thrombocytopenic purpura: case reports and methodological approach.

Six emblematic cases of neonatal thrombocytopenic purpura (NTP) due to different etiologic factors are described. Various methods for the detection of platelet and leukocyte antibodies are considered: platelet suspension and lymphocyte immunofluorescence tests (PSIFT and LIFT), solid-phase platelet antibody detection test (Capture-P), immune-enzymatic assay on platelet suspension (ELISA) and on solid-phase platelets (Capture-P-ELISA), lymphocytotoxicity (Lctx). Furthermore, chloroquine stripping of HLA antigens and monoclonal antibody (MoAb) treatment of target platelets specific antigens are described. The technical characteristics and advantages of each method are discussed. The authors stress that a step-by-step investigation employing an integrated system that includes various methods can correctly supply the pathogenetic information necessary for the physician to undertake the best therapeutical approach.

Effect of long-term treatment with sodium cromoglycate on non-specific bronchial hyperreactivity in non-atopic patients with chronic bronchitis.

Reduction in non-specific bronchial hyperreactivity has been reported in atopic asthmatic patients as a consequence of long-term treatment with sodium cromoglycate. As bronchial hyperreactivity is an undesirable feature in other forms of obstructive airways disease, we examined the effect of regular treatment with sodium cromoglycate (20 mg, 4 times daily, for 30 days) in a group of non-atopic bronchitic subjects who showed a significant bronchoconstrictor response to the inhalation of ultrasonically nebulised distilled water (fog challenge). After 30 days treatment with sodium cromoglycate, there was a significant reduction in response to fog challenge, compared with pretreatment values. There was a washout period of 12 h between the administration of the last dose of sodium cromoglycate and the second fog challenge. The possible mechanisms involved and the clinical significance of these findings are discussed.