Blood transfusion services: organization is integral to safety.

There are six steps to a safe blood transfusion service. The primary steps are: (i) a national policy for the blood transfusion service with time-bound programmes; (ii) a centrally coordinated, structured and organized blood transfusion service for a country/state under a defined authority; and (iii) a blood transfusion service based on an organized voluntary blood donor programme. The complementary steps are: (i) screening blood for transfusion-associated infections (TAI) appropriate to the region; (ii) rational use of available blood; and (iii) qualified personnel to head and manage the blood transfusion service. None of these steps are in place in India and the high incidence of TAI in our patients is a consequence of this deficiency. Lack of understanding of the issues related to a safe blood transfusion service has led to an emphasis on screening donor blood for infections as a means of ensuring safe blood transfusion. Screening donor blood for TAI without implementing the critical primary steps has little impact, as evidenced by the high levels of post-transfusion hepatitis which ranges from 7% for hepatitis B and C combined in patients receiving approximately 1-7 units of blood to > 50% and > 30%, respectively, for patients receiving multiple transfusions. Basic licensing standards for blood banks with regard to space, and the quality and quantity of medical staff have remained unchanged over the past three decades. This compounds the problem and society pays the price.

Cryopreservation of Rh negative blood for improved storage & utilisation by means of indigenous freezing bags & solutions & manual deglycerolisation.

BACKGROUND & OBJECTIVES: Cryopreservation allows donor blood to be stored for years, rather than weeks as in liquid storage. This is an established procedure in countries with a developed blood transfusion service. Cryopreservation has not been introduced in India, possibly because of the presumed high cost and complexity of the procedure. An attempt is made in this study, to cryopreserve Rh negative blood in a mechanical freezer using indigenous bags and solutions and manual deglycerolisation to reduce the cost of preservation. METHODS: RBCs to be frozen were weighed and transferred by sterile welding to an 800 ml freezing bag. Based on RBC weight, 400-500 ml of glycerol (5.7 MpH 6.8) was added as cryopreservative. After extracellular and intracellular equilibration, excess glycerol was removed by centrifugation. Glycerolised RBCs were frozen at -80 degrees C in a mechanical freezer. Cryopreserved units were thawed at 37 degrees C and deglycerolised. Twenty one patients were transfused with the frozen deglycerolised RBCs after the usual pre-transfusion tests. RESULTS: Haematocrit (Hct) values of the frozen deglycerolised units, complied with required standards, before addition of glycerol and post glycerolisation. RBC recovery was more than 80 per cent and Hct 83.3 per cent after deglycerolisation. Twenty one patients transfused with the frozen deglycerolised blood experienced no adverse effects and showed a 24 h mean post transfusion Hb increment of 0.73 g/dl. INTERPRETATION & CONCLUSION: Cryopreservation, unlike liquid storage, allows Rh negative blood of the required ABO groups to be stocked. Cryopreservation also improves its utilisation, reduces wastage and helps supplement the liquid stocks of Rh negative blood. The use of indigenous freezing bags and manual deglycerolisation has resulted in an inexpensive procedure, which can be integrated, with minor inputs, into any blood bank that is already preparing blood components.

Blood group gene frequency in a selected north Indian population.

Gene frequencies have been calculated from 6334 blood donors who were tested at a referral hospital in north India, for ABO & Rh and from > 350 donors who were tested for other blood groups. The Hardy Weinberg equation for 2 allel systems and the Bernstein method for 3 or more allel systems have been employed for calculating gene frequencies. The predominance of blood group B (37.39%), Rh D negative frequency of 4.63 per cent, predominance of M gene (0.6383) and M s haplotype (0.4464) and S gene frequency below 0.3 (0.2069) agrees with earlier data. The new findings include the presence of the allels Fy (a-b-) (0.44%) in the Duffy group, S- s- (1.16%) in the Ss group and JK (a-b-) (0.54%) in the Kidd blood group system. These have not been reported in the Indian population.

Fibronectin levels in Indian neonates in health & disease.

Cord blood samples were estimated for serum fibronectin (Fn) by immunoelectrophoresis (IE) and enzyme linked immuno sorbent assay (ELISA) in 250 newborn healthy and sick infants classified into 6 categories: i.e., term appropriate for date (TAFD), preterm appropriate for date (PTAFD), term small for date (TSFD), preterm small for date (PTSFD), birth asphyxia (BA) and septicemia (SEP). TAFD infants were assayed for plasma Fn in addition. Comparison of Fn levels in the different groups by the Wilcoxan rank sum test indicated no significant difference between term and preterm infants, between PTAFD and PTSFD, TAFD and TSFD and in infants with and without birth asphyxia. Babies with septicemia had a significantly (P < 0.01) lower Fn level (29.97 +/- 29.03 mg/l) than those with no septicemia (42.77 +/- 30.20 mg/l). TAFD infants had Fn levels (serum 41.44 +/- 31.08 mg/l, plasma 85.20 +/- 33.38 mg/l) that are less than half the levels reported in the Western literature for newborn term infants. A possible cause could be the associated medical problems in mothers as 41 per cent of mothers of TAFD infants had conditions such as pregnancy induced hypertension, gestational diabetes, rheumatic heart disease, infection etc.

Alloimmunisation to platelet transfusions in the Indian patients.

Twenty nine patients of acute and chronic leukemia undergoing chemotherapy and receiving blood transfusions (BT) and platelet transfusions (PT) from random donors (3-20 PT from 4-56 donors) were followed up for alloimmunisation using the platelet immunofluorescence test. Two women patients aged 65 and 28 yr reacted positive. Both patients had received multiple BT but no PT at the time of testing. Both were parous women. Our results point to the need to test for alloimmunisation prior to starting PT in parous women who have received multiple BT, although a study on larger number of patients is necessary for confirmation.

Extraction & assay of fibronectin from stored plasma.

Fibronectin was extracted from 20 units of 3 days old plasma by the heparin cold precipitation technique using 15 or 30 units of sodium heparin per ml of plasma. Immunoelectrophoresis of the extracted fibronectin showed it to be 131.37 +/- 24.73 times concentrated over fibronectin levels in standard plasma, with a mean recovery of 73.99 +/- 18.40 per cent. Corresponding figures by ELISA were 118.95 +/- 27.99 (concentration) and 73.99 +/- 18.40 (per cent).