Platelet aggregation and physiological anticoagulants in sickle-cell disease

During the period January 2002- December 2004, we assessed 30 sickle- cell anaemia patients admitted to hospital in Al Khobar with vaso- occlusive crisis for levels of antithrombin [AT] III, protein C [PC] and protein S [PS]. We also did platelet aggregation studies. Steady state levels were assessed during follow- up and compared with 36 adult controls. Levels of PC, PS and AT III in the group were significantly higher than in those in vaso- occlusive crisis and those in steady state control [P < 0.001]. There was a statistically significant difference between controls and patients for all platelet factors except adrenaline. There was no significant difference between the levels of PC, PS, aggregation AT III and platelet aggregation variables in patients in the steady state and in vaso- occlusive crisi

Red cell alloimmunization in sickle-cell anaemia patients

This study in King Fahd Hospital of the University, Saudi Arabia, assessed the frequency of alloimmunization to red cell antigens in sickle-cell anaemia patients over 1996-2004 in order to evaluate the risk of alloimmunization and identify the most common alloantibodies. A retrospective analysis of the transfusion history and medical records of 350 patients aged 2 to 75 years who had received at least 1 transfusion found that 48 patients had developed alloantibodies [13.7%]. The most common alloantibodies detected were: anti-E alone [18.8%], nonspecific [12.5%], inconclusive [12.5%], anti-K [10.4%] and anti-c 3 [6.3%]. Some patients had 1 alloantibody, while others more than 1 and even multiple antibodies. Nine patients had a persistent positive direct antiglobulin test