RESUMEN

OBJECTIVE: Fetal and neonatal alloimmune thrombocytopenia (AIT) caused by feto-maternal incompatibility at the HPA-1a (PLA-1) locus is well characterized. Alloimmunization and disease caused by HPA-3a is rare. STUDY DESIGN: We conducted a retrospective analysis of all known cases of AIT caused by HPA-3a incompatibility identified at 3 major reference laboratories from 1986 to 1996. Platelet antigen typing and antibody specificity were determined by serologic evaluation. In some cases confirmatory genotyping was performed. RESULTS: Fourteen cases of anti-HPA-3a-induced AIT in 11 families were identified. Five patients had a previous affected sibling, and 2 cases were firstborn children. All patients had severe thrombocytopenia at birth (platelet count <20 x 10(9)/L). Regardless of therapy, the median time to platelet recovery was 6 days (range, 3 to 23 days). Two (15%) patients had documented intracranial hemorrhage, 1 with severe sequelae including apnea and convulsions. A literature review describing 16 additional patients corroborates the finding of severe thrombocytopenia and a significant incidence of intracranial hemorrhage caused by HPA-3a incompatibility. CONCLUSION: AIT caused by incompatibility of HPA-3a is similar in severity to disease caused by incompatibility of HPA-1a. Affected families should be appropriately counseled and considered for antenatal therapy.

Asunto(s)

Antígenos de Plaqueta Humana/inmunología , Púrpura Trombocitopénica Idiopática/inmunología , Hemorragia Cerebral/etiología , Humanos , Recién Nacido , Recuento de Plaquetas , Transfusión de Plaquetas , Púrpura Trombocitopénica Idiopática/terapia , Estudios Retrospectivos

RESUMEN

We describe a case of thrombocytopenia and deep venous thrombosis in a boy who received heparin to maintain patency of a central venous catheter. Measurement of the release of serotonin labeled with carbon 14 confirmed the presence of heparin-induced thrombocytopenia. Children receiving heparin therapy should be monitored for the possibility of heparin-induced thrombocytopenia.

Asunto(s)

Heparina/efectos adversos , Trombocitopenia/inducido químicamente , Tromboflebitis/inducido químicamente , Adolescente , Anastomosis Quirúrgica , Plaquetas/inmunología , Cateterismo Venoso Central/instrumentación , Humanos , Isoanticuerpos/análisis , Pierna/irrigación sanguínea , Masculino , Recuento de Plaquetas/efectos de los fármacos , Vena Subclavia , Trombosis/inducido químicamente , Válvula Tricúspide/anomalías , Válvula Tricúspide/cirugía

RESUMEN

Barley stripe mosaic virus (BSMV) is known to have unusual strain-specific variations in the number of high molecular weight RNAs that can be resolved by gel electrophoresis. Analysis with recombinant DNA clones has revealed that all strains contain three distinct hybridizing species of RNA, which we now designate alpha, beta and y. The alpha- and beta-RNAs are about 4200 and 3650 nucleotides (NT), respectively, but the gamma-RNAs vary in size depending on the strain. The gamma-RNA of the Type strain is 3650 NT, and is difficult to resolve from beta-RNA by gel electrophoresis. However, the gamma-RNA of the North Dakota 18 (ND18) strain is 3250 NT and is clearly separated from beta-RNA. The results presented below show that the Argentina mild (AM) strain contains a mixture of gamma-RNAs of 3650, 3250, and 2900 NT. The 3650- and 3250-NT gamma-RNAs appear to be functional because AM subclones containing either 3650- or 3250-NT gamma-RNA can be isolated from plants inoculated with low concentrations of virus. The 2900-NT gamma-RNA is probably not capable of functioning as a genomic RNA because this RNA is not a component of any of the AM subclones.