Development of inhibitors in patients with haemophilia from India

K. Ghosh et al., Development of inhibitors in patients with haemophilia from India, HAEMOPHILIA, 7(3), 2001, pp. 273-278
Citations number
Categorie Soggetti
Journal title
ISSN journal
1351-8216 → ACNP
Year of publication
273 - 278
SICI code
(F)our hundred and seven patients (352 haemophilia A and 55 haemophilia B) were investigated for the presence of factor VIII and IX inhibitors. Twenty -four out of 292 severe and two out of 36 moderate haemophilia A patients s howed the presence of inhibitors. The mean age at development of inhibitors was 17.7 years (range 6-52 years). In 12 patients the inhibitors were dete cted due to suboptimal response to factor replacement therapy (symptomatic) and in the remaining 14 patients the inhibitors were detected during the r outine screening of the patients' samples for inhibitors. They had, however , responded well to the usual doses of factor concentrates and there was no suspicion in these patients that they had developed an inhibitor (asymptom atic). There were two families in which the inhibitors were detected in mor e than one family member. The level of inhibitors in symptomatic patients r anged from 2.2 Bethesda units (BU) mL(-1) to 460.6 BU mL(-1), and in asympt omatic patients it ranged from 0.8 BU mL(-1) to 3.2 BU mL(-1). The inhibito rs persisted in all patients except one, who developed an inhibitor postope ratively for a brief period of 3 months. All these patients were followed u p from first factor exposure and were tested for inhibitors at least twice a year. The mean number of exposure days before they developed inhibitors w as 47.5 exposure days (range 17-98 exposure days). No inhibitors appeared a fter more than 100 exposure days in any of the patients. When 50 consecutiv e patients were investigated for intron 22 inversions of the factor VIII ge ne, 17 patients were found to be positive for inversions (10 proximal inver sion; seven distal inversion) out of whom four patients developed inhibitor s, three patients belonging to the same family. Out of 35 haemophilia B pat ients, only one patient developed an inhibitor. The overall prevalence of i nhibitors was thus 8.2%, which is similar to the reports from western count ries, prior to the introduction of highly purified factor concentrate thera py.