Lorenzo's oil and platelet activation in adrenomyeloneuropathy and asymptomatic X-linked adrenoleukodystrophy.

X-linked adrenoleukodystrophy (X-ALD) is an inherited disorder of peroxisomal beta-oxidation, which results in accumulation of very long-chain fatty acids, causing damage to the nervous system, adrenal cortex and testis. The two most frequent phenotypes are childhood cerebral adrenoleukodystrophy (CCALD) and adrenomyeloneuropathy (AMN). Some affected males demonstrate no clinical signs (asymptomatic ALD), whereas female carriers can also be affected.

Max(a), a new low-frequency platelet-specific antigen localized on glycoprotein IIb, is associated with neonatal alloimmune thrombocytopenia.

We have identified a new platelet-specific alloantigen, Max(a), responsible for a typical case of neonatal alloimmune thrombocytopenic purpura. The maternal serum reacted strongly with paternal platelets in the platelet immunofluorescence test, whereas platelet alloantigen typing showed that no known human platelet antigen (HPA)-system was involved. In the monoclonal antibody (MoAb)-specific immobilization of platelet antigens (MAIPA) assay, the new antigen was located on the platelet membrane glycoprotein (GP) IIb-IIIa complex, but immunoprecipitation and immunoblot experiments to further localize the antigen failed.

Glanzmann's thrombasthenia caused by homozygosity for a splice defect that leads to deletion of the first coding exon of the glycoprotein IIIa mRNA.

Glanzmann's thrombasthenia (GT) is the result of the absence or of an altered and dysfunctional expression on the platelet membrane of the fibrinogen receptor (glycoprotein [GP] IIb/IIIa complex). Various molecular genetic mechanisms have been found to be responsible for this inherited disease. In a patient with a severe type of GT, we have found a splice variant in the GP IIIa gene that leads to premature chain termination.

P-selectin mediates Ca(2+)-dependent adhesion of activated platelets to many different types of leukocytes: detection by flow cytometry.

Previous studies have shown that thrombin-activated platelets interact through the P-selectin with neutrophils and monocytes. To identify other types of leukocytes capable of such an interaction, eosinophils, basophils, and lymphocytes were isolated from whole blood. Binding of these cells to activated platelets was examined in a double immunofluorescence assay and the results show that activated platelets not only bind to neutrophils and monocytes, but also to eosinophils, basophils, and subpopulations of T lymphocytes.