ADAMTS-13 antigen and activity levels in thrombocytopenic disorders including thrombotic thrombocytopenic purpura in Kuwait.

BACKGROUND/AIMS: While deficiency of a disintegrin and metalloprotease with thrombospondin-1-like domains (ADAMTS-13) was reported as the basis for the pathogenesis of thrombotic thrombocytopenic purpura (TTP), low levels have also been found in other thrombocytopenic disorders. This study was conducted to characterize the activity and antigen levels of ADAMTS-13 and von Willebrand factor (vWF) in patients with different thrombocytopenic disorders in Kuwait. METHODS: Forty healthy subjects and 41 patients with different thrombocytopenic disorders were recruited for this study. ELISA tests were used to measure ADAMTS-13 and vWF activity and antigen levels in patients and controls. RESULTS: All TTP patients had severely deficient ADAMTS-13 activity (<5%), which was significantly lower than that of controls (p < 0.001). Severe deficiency of ADAMTS-13 was also found in some, but not all, patients with idiopathic thrombocytopenic purpura, acute leukemia and sepsis. CONCLUSIONS: This study is the first to report ADAMTS-13 levels in this part of the world. ADAMTS-13 was found to be severely deficient in TTP patients. We present evidence that significantly lower levels of ADAMTS-13 were not specific for TTP and can be found in other thrombocytopenic disorders. We also hypothesize that clinical manifestation of TTP may not be solely due to ADAMTS-13 deficiency, and there might be other contributing factors, since the deficiency was also found in some healthy controls.

Effect of sickle cell trait and B-Thalassemia minor on determinations of HbA1c by an immunoassay method.

OBJECTIVE: Glycated hemoglobin determination is being used worldwide to monitor the efficiency of blood glucose control and to plan treatment in diabetes mellitus patients. Several methods are used for measuring glycated hemoglobin, but a possible interference by hemoglobin variants is a major concern. The use of immunoassay methods with glycated hemoglobin-specific antibodies is supposed to overcome this problem. We are evaluating the effect of the most prevalent hemoglobinopathies in the region (sickle trait hemoglobin and B-Thalassemia) on the immunoassay method used in determining glycated hemoglobin. METHODS: Eighty-one whole blood sample hemolysates were tested for glycated hemoglobin using Beckman Synchron LX20 system, 37 of these normal adult hemoglobin represented 22 diabetic and 15 non-diabetic samples. Of the remaining 44 samples, 28 were from B-thalassemia minor and 16 from sickle-cell trait sickle trait hemoglobin patients, all non-diabetic. The samples were collected in ethylenediaminetetraacetic acid anticoagulant and analyzed immediately or stored at 4?C for not more than 2 days. RESULTS: Sickle trait hemoglobin had no effect on glycated hemoglobin measurement by Synchron LX20 while B-thalassemia minor blood elevated the value of glycated hemoglobin to the range of diabetic cases. CONCLUSION: Synchron LX20 glycated hemoglobin immunoassay method gave falsely high glycated hemoglobin results with B-thalassemia minor patient samples. Therefore, while interpreting the results of Synchron LX20 glycated hemoglobin, the patients history regarding hemoglobinopathies should be checked.