Prevalence of Anti-HLA and Anti-GPIIB/IIIA Allo-Immunization in Patients with Glanzmann Thromboasthenia: Experience of a Single Center.

Background. Platelet transfusions, the main therapy of Glanzmann Thromboasthenia (GT), can induce an allo-immunization against HLA antigens and GPIIb/IIIa complexes, with a possible reduction of efficacy of subsequent treatments.

Aims. To investigate the development of anti-HLA antigen and anti-GPIIb/IIIa complexe allo-immunization in GT transfused patients, and to evaluate the efficacy of replacement therapy.

Patients and Methods. From 1975 onwards, we have followed 17 GT patients; 13 type I, 3 type III, 1 not classified; 8 men, 9 women; median age at diagnosis 9.8 years (range 1–44.5); the median age at the time of this study was 35.5 years (range 23.6–68.5). Our patients had shown at least once in their life the following symptoms: 10/17 epistaxis; 5/17 gastrointestinal hemorrhage; 5/17 oropharingeal hemorrhage; 4/17 muscle hematoma; 2/17 bleeding for traumatic injury; 2/17 hemarthrosis; 2/17 hematuria; 1/17 intracranial hemorrhage; 1/17 hematothorax; 1/17 otorrhagia. Five out of 9 women had experienced meno-metrorrhagia. Ten major and 22 minor surgical procedures had been performed. Two spontaneous deliveries and 3 cesarian sections with 5 live births had been reported; moreover, 2 abortions had occurred, 1 spontaneous and 1 voluntary. Globally, 9/17 patients had been transfused with platelets and red blood cells (RBC); 5/17 only with platelets; 2/17 only with RBC. One patient has never been transfused. Platelet transfusions have always been hemostatically effective. All transfused patients have been investigated for anti-HLA and anti-GPIIb/IIIa allo-antibodies,.

Results. Positivity for allo-antibodies could be demonstrated in 4/15 patients (27%): isolated for anti-HLA in 2; isolated for anti-GPIIb/IIIa in 1; combined in 1.

Conclusions. The prevalence of allo-immunization (27%) is inferior to recent literature data (50%). While positivity for anti-HLA (3/15, 20%) agrees with the recently reported data (22%), positivity for anti-GPIIb/IIIa (13%) is inferior (35%). Presence of allo-immunization did not compromise the efficacy of platelet transfusions.