Two cases of neo-natal thrombocytopenia due to maternal iso-immunization against leuco-platelet antigens

Feto-maternal alloimmune thrombocytopenia: a literature review and statistical analysis

Exploring prognostic factors that determine outcomes in fetomaternal alloimmune thrombocytopenia (FMAIT), a search of Medline was performed covering the years 1966 to April 1998. 376 articles were collected and reviewed; 140 articles contained the case histories of 297 mothers and 433 pregnancies that fulfilled entry criteria. More than 30 data variables were sought from these cases. The data were analysed using SPSS and Arcus Quickstat Biomedical. Nineteen different antigen incompatibilities were documented, the majority being human platelet antigen (HPA)-1a (77.3%), HPA-3a (3.5%) and HPA-5b (3.5%). The relative risk reduction (RRR) in mortality with any intervention was 57% (0.19-0.77) p = 0.009. Treatment of HPA-1a (PlA1) pregnancies with intravenous immunoglobulin (IVIG) increased the likelihood of a neurologically normal outcome, relative risk (RR) 1.68, confidence interval (1.3-2.2) p = 0.0003. Treatment of HPA-1a (PlA1) pregnancies with only antenatal complementary platelet transfusions increased the likelihood of a neurologically normal outcome, RR 1.63 (1.1-2.1) p = 0.01. Despite reviews of more than 400 cases of FMAIT, few prognostic variables are identifiable. Although IVIG appears to reduce the risk of intracranial haemorrhage (ICH), the dosage and timing of IVIG treatment was varied. This study highlights the need for standardised and directed research.

Association of neonatal thrombocytopenia and maternal anti-HLA antibodies

In order to evaluate the influence of maternal anti-HLA antibody on neonatal thrombocytopenia, clinical features and maternal anti-HLA antibody of three groups of infants (19 thrombocytopenic and low birth weight, 27 nonthrombocytopenic and low birth weight, and 80 healthy full-term) were investigated. The incidence of positive maternal anti-HLA antibodies in the three groups was 73.7%, 29.6% and 27.5%, respectively. Thrombocytopenia in small-for-gestational-age (SGA) infants was closely related to the presence of maternal anti-HLA antibodies. Among 20 SGA infants (11 thrombocytopenic, 9 non-thrombocytopenic), anti-HLA antibody was detected in 10 mothers (90.9%) of thrombocytopenic SGA infants, while it was positive in only one mother (11.1%) of nonthrombocytopenic SGA infants. Investigation of the SGA infants revealed that in those whose mothers were sensitized to HLA antigen, not only the platelet count but also the leukocyte and lymphocyte counts in the first week of life were significantly lower than in infants whose mothers were not sensitized. The results suggest that the presence of maternal anti-HLA antibody is a cause of neonatal thrombocytopenia especially in SGA infants.

Neonatal alloimmune thrombocytopenia. Case reports, diagnostic and therapeutic considerations

Two families are presented, where the mothers have given birth to children with neonatal alloimmune thrombocytopenia (NAITP) due to immunization towards the platelet specific antigen PIA1, which is responsible for most of the cases with NAITP. Anti-PIA1 has previously been difficult to demonstrate, but current techniques, such as the platelet suspension immunofluorescence test (PSIFT) used here, have made routine laboratory diagnosis possible. Both mothers in these families were HLA-B8 positive. This antigen shows strong association with PIA1 immunization.

Complement fixing and lymphocytotoxic antibodies in serum of pregnant women at delivery. III. Clinical observations

The investigation comprised 2,008 pregnancies. Sera fnd lymphocytotoxic antibodies (LCTAb). 14 women had only CFPAb, 44 had CFPAb and LCTAb, 224 had only LCTAb. In 3 of 481 cord blood serum samples LCTAb were demonstrated. No cases of neutropenia or thrombocytopenia was observed. No association was found between CFPAb or LCTAb and stillbirth, birth defects, degree of bilirubinaemia, diseases of the newborn, or placental weight. It was suggested that the applied lymphocytotoxicity test detects both in vivo cytolytic antibodies and enhancing antibodies, which may explain the results.