Glimpse on Hemostatic Changes Produced By Plasmapheresis.

Background: Aphaeresis is a term that means to separate or to take away. The basic idea of aphaeresis is efficient removal of a circulating cellular blood component, either cells (Cytopheresis) or plasma solute (plasmapheresis, plasma exchange).Thus, the treatment goal of aphaeresis is to remove the circulating cell or substance directly responsible for the disease process. Acceleration and development of aphaeresis applications had taken place with the arrival of automated cell separators in 1970s that ensure selectively removal of one or more of blood components from the blood and return the remainder to the individual. Plasmapheresis is separation of plasma from blood cells which are returned to the body. It is accompanied by multiple changes in haemostatic system. As many coagulation factors are removed during procedure, changes in selective parameters: Prothrombin Time (PT), Partial Thromboplastin Time (PTT), Thrombin Time (TT), Fibrinogen (FNG) & platelets count are found when the replacement fluids devoid from coagulation factor are used. Patients and Methods: This clinico-haematological study conducted during a period of six months, from February 2004 to July 2004 at the National Blood Transfusion Center (NBTC) in Baghdad & 50 patients underwent Therapeutic Plasma Exchange (TPE) for various disorders with the use of two types of automated blood cell separators (Haemonetics MCS + which represent an intermittent flow centrifugation technique – IFC & Fresenius AS. TEC 204 which represent the continuous flow centrifugation technique - CFC) in this study, but no instrument type influenced the coagulation screening tests. Results: The changes in all selective parameter: Prothrombin Time (PT), Partial Thromboplastin Time (PTT), Thrombin Time (TT), Fibrinogen (FNG), Platelets count, Haemoglobin (Hb) and Packed Cell Volume (PCV) were significant after Therapeutic Plasma Exchange (TPE). There was no significant difference in changes in crystalloid group from that in Fresh Frozen Plasma group. In crystalloid group, significant correlation was observed between Prothrombin Time (PT), Activated Partial Thromboplastin Time (APTT), Thrombin Time (TT) & volume of Plasma Exchanged (PE) /session, while spacing between sessions and the number of sessions is significantly correlated with Thrombin Time (TT). Plasma fibrinogen concentration and platelets count were decreased in the patients included in our current study. Conclusion: There is no significant difference in changes in haemostatic system whether crystalloid or diluted Fresh Frozen Plasma (FFP) was used as replacement fluid. Thus, crystalloid, solution devoid of coagulation material can be used as a replacement fluid in the Therapeutic Plasma Exchange (TPE) if the volume of Plasma Exchanged (PE) is small. These results are of vital importance from the practical & public health point of view in minimizing the usage of blood components((i.e. Fresh Frozen Plasma (FFP) which is a potential source of Transfusion Transmissible Infections (TTIs) worldwide)) & replaced by crystalloid solution as a safer replacement fluid substitute in Therapeutic Plasma Exchange (TPE) process

Alloimmunization in Transfusion Dependent Thalassaemic Patients.

Background: Life-long red blood cells (RBCs) transfusion remains the main treatment for severe cases of thalassaemia. The development of anti-RBC antibodies (alloantibodies and for autoantibodies) can significantly complicate transfusion therapy. Some alloantibodies are hemolytic and may cause, though not invariably, hemolytic transfusion reactions and limit the availability of further safe transfusion. Erythrocyte autoantibodies appear less frequently in blood cross match. Patients and methods: This is a descriptive study ducted at Al-Karama Thalassaemia Center in Baghdad .The sampling was done from September 2005 to April 2006 and all patients were diagnosed as Thalassaemia Major according to the hemoglobin electrophoresis results were included in the study (60 patients). Antibodies identification was carried out on serum employing commercial two cell panel, using standardized blood bank methods. If the patients were found to have irregular red cell alloantibodies, then the antibodies identification was performed by indirect coombs test using 18 panel cells. Results: Sixty thalassaemic patients were included in the study, 35 patients were males and 25 females. The age of patients ranged from 18 months to 33 years (median 25.2 7). Irregular red cell antibodies were found in 9 patients (15%). Mean age of patients who developed red cell antibodies was 25.2±7.0 years. Two patients developed autoantibodies (3.3%) and seven patients developed alloantibodies (11.7%).Six patients developed single antibodies (10%) while 3 patients developed multiple antibodies (5.0%). Total anti-k was found in 4 patients (6.7%), two patients had anti-k 1 and two patients had anti-k2. The higher rate of alloimmunization was in the rhesus Rh system, which was detected in (8.3%) 5 patients (one patient developed anti-D, one patient developed anti-c and 3 patients developed total anti-e). while total anti-M presented in 3 patients(5.09%)while one patient developed anti-Lea (1.7%).  Conclusion: We concluded that there is a relatively high rate of alloimmunization in our set of patients when compared to data from Iraq geographic region. However, more data required from various other large centers in Iraq. It is recommended that red cell alloimmunization should not be overlooked in patients with B- thalassaemia major receiving regular blood transfusion. Those patients with Thalassaemia Major repeatedly suffer from hemolytic transfusion reaction or not being able to maintain hemoglobin at desired level in spite of regular transfusion due to the presence of irregular alloantibodies in their circulation. Proper blood cross matching, regular screening, detection & identification of the red blood cell alloantibodies would add towards the better management of these patients & reduce the chance of development of these irregular antibodies & other possible additional alloantibodies