BACKGROUND: Maternal alloantibodies against the five common human platelet antigen (HPA) systems (HPA-1 to -3, -5, and -15) are found in only 20% of cases referred for fetal and neonatal thrombocytopenia (FMAIT) investigations. The question asked was whether mismatches for the remaining 11 low-frequency HPAs (HPA-4 and -6bw to -17bw) might in part explain the remaining 80% of cases. STUDY DESIGN AND METHODS: A total of 1054 paternal DNA samples from referred FMAIT cases (among which 223 cases where antibodies against a common HPA were found) were genotyped for 11 low-frequency HPAs as well as a recently discovered polymorphism (ITGA2B-C2320T). The initial genotyping was carried out by TaqMan and potential heterozygotes were confirmed by DNA sequencing. Clinical and serologic data were collected for each case with a heterozygote father. RESULTS: In total, eight heterozygous fathers were identified: four for HPA-6w, one each for HPA-10w and -11w, and two for HPA-12w. Maternal antibodies against the corresponding antigen were identified in four of the eight cases. In two of these cases, antibodies against HPA-1a and HPA-1b were also found. CONCLUSION: It was concluded that the minor alleles of HPA-4 and -6bw to -17bw are exceptionally rare in the Caucasian population and therefore do not explain the large number of FMAIT referrals which test negative for the common HPA antibodies.
BACKGROUND: Maternal alloantibodies against the five common human platelet antigen (HPA) systems (HPA-1 to -3, -5, and -15) are found in only 20% of cases referred for fetal and neonatal thrombocytopenia (FMAIT) investigations. The question asked was whether mismatches for the remaining 11 low-frequency HPAs (HPA-4 and -6bw to -17bw) might in part explain the remaining 80% of cases. STUDY DESIGN AND METHODS: A total of 1054 paternal DNA samples from referred FMAIT cases (among which 223 cases where antibodies against a common HPA were found) were genotyped for 11 low-frequency HPAs as well as a recently discovered polymorphism (ITGA2B-C2320T). The initial genotyping was carried out by TaqMan and potential heterozygotes were confirmed by DNA sequencing. Clinical and serologic data were collected for each case with a heterozygote father. RESULTS: In total, eight heterozygous fathers were identified: four for HPA-6w, one each for HPA-10w and -11w, and two for HPA-12w. Maternal antibodies against the corresponding antigen were identified in four of the eight cases. In two of these cases, antibodies against HPA-1a and HPA-1b were also found. CONCLUSION: It was concluded that the minor alleles of HPA-4 and -6bw to -17bw are exceptionally rare in the Caucasian population and therefore do not explain the large number of FMAIT referrals which test negative for the common HPA antibodies.
Authors: Julie A Peterson; Shannon M Pechauer; Maria L Gitter; Adam Kanack; Brian R Curtis; Jeff Reese; Vasudeva M Kamath; Janice G McFarland; Richard H Aster Journal: Transfusion Date: 2011-11-09 Impact factor: 3.157
Authors: Julie A Peterson; Maria Gitter; Daniel W Bougie; Shannon Pechauer; Kathleen A Hopp; Brad Pietz; Aniko Szabo; Brian R Curtis; Janice McFarland; Richard H Aster Journal: Transfusion Date: 2013-10-16 Impact factor: 3.157