Purification of human hemopoietic stem cells for transplantation in Thailand.

Stem cell transplantation (SCT) has become the therapy of choice for many hematologic and immunologic disorders. At present, only 25% of patients have suitable HLA-identical donors. In an attempt to increase the donor pool for SCT in Thailand and Southeast Asia, we developed a program whereby parents and mismatched siblings can be used as donors. In this preliminary study, after granulocyte-colony-stimulating factor (G-CSF) was given to adult donors, peripheral blood stem cells (PBSC) were collected and CD34+ cells purified using a CliniMACS immunomagnetic device (Miltenyi Biotec, Germany). In seven experiments, purified CD34+ cells could be obtained from G-CSF-stimulated PBSC in large numbers (1.71 +/- 0.19 x 10(8)), with high purity (93 +/- 2.4%) and excellent recovery (64.28% - 85.62%). Immune reactive T and NK cells were adequately depleted to less than 0.2%. The purification procedure can be completed within 3 hours. In conclusion, a clinical stem cell purification program using this novel device is now established in Thailand and for the first time in Southeast Asia. This should allow further development of advanced SCT therapy including haploidentical and mismatched CD34+ SCT for patients' lacking HLA-identical donors in this region.

Exchange transfusion in severe falciparum malaria.

Malaria associated with complications or a fatal outcome is caused by Plasmodium falciparum. The mortality due to this disease is parallel to the degree of parasitemia. Successful use of exchange blood transfusion as a therapeutic adjunct for this infection was reported. The rationale for this form of therapy is based on (1) rapid reduction in parasite load by exchange transfusion, (2) removal of toxic substances and (3) reducing microcirculatory sludging. We describe here thirteen cases of severe falciparum malaria treated with infusion of quinine dihydrochloride and exchange transfusion 2,320-8,000 ml of whole blood. We observed that the greatest reduction in the average circulating infected red blood cells, from 20.7 per cent to 9.3 per cent, seemed to occur early in the first 2,000 ml of blood exchange and the parasitemia often reduced to 5.1 per cent in patients who had 4,000 ml of blood exchange. In order to reduce the initial parasitemia to 5 per cent by exchange transfusion, we suggest the volume of exchange transfusion should be 2,000 ml for average parasitemia 10 per cent, 4,000 ml for parasitemia > 20 per cent and 2,000-4,000 ml for parasitemia 10-20 per cent.

Serological infectious disease markers in blood donated at Siriraj Hospital.

A retrospective study was done on blood donated at Department of Transfusion Medicine, Siriraj Hospital from 1987 to 1996. The total number of 274,288 units were donated from three types of blood donors : voluntary (61.31%), replacement (35.57%) and paid (3.12%) during 1987-1993. The serological infectious disease markers were found to be highest in replacement donors. The prevalence of anti-HIV, HIV antigen, HBsAg, anti-HCV and positive VDRL were 0.7%, 0.02%, 6.2%, 1.6% and 2.3% respectively. The prevalence of these markers in voluntary donors were 0.3%, 0.01%, 2.6%, 0.9% and 1.0% respectively. In conclusion, the serological infectious disease markers in blood donated at Siriraj Hospital during the 10 years period consisted of 0.44% anti-HIV, 0.01% HIV antigen, 3.7% HBsAg, 1.13% anti-HCV and 1.40% positive VDRL. It was also noted that the prevalence of these markers in new blood donors were higher than those found in repeat blood donors.

Acute hemodilution and autotransfusion in cardiac surgery: a comparison between rather healthy and high risk patients.

The effects of acute normovolemic hemodilution and autologous blood transfusion were studied in open heart patients, compared with rather healthy patients, NYHA class 1-2 and the high risk patients, NYHA class >2. Thirty-nine patients were involved in this study, 15 of them were identified as the rather healthy group while 24 patients belonged to the high risk group. Acute hemodilution was performed after anesthetic induction and before heparinization. Using an equal volume of polygeline 3.5 per cent (Haemaccel) to replace autologous blood removal, the number of patients who needed inotropic support to achieve normal arterial blood pressure was not significantly different between the groups. Following retransfusion of pump perfusate and autologous blood after the termination cardiopulmonary bypass, the number of patients who received additional homologous blood as well as the amount used percase were significantly less in the rather healthy patients. There was none in this group, but half of the high risk patients suffered from serious perioperative complications and one died. We conclude that this technique is safe and benefits blood conservation in rather healthy cardiac patients undergoing open heart surgery, but special precautions against risk should be considered in high risk patients.

Autologous blood and platelet-rich plasma reinfusion reduce post-operative blood and blood component therapy after cardiopulmonary bypass.

To study blood and blood component transfusion following reinfusion of platelet-rich plasma (PRP)/and autologous blood, 33 patients undergoing open-heart surgery were randomly divided into three groups. Group I comprised 13 patients as controls; group II, eight patients from whom were collected PRP 15-20 percent of plasma volume with Haemonetics; and group III, 12 patients from whom were collected PRP and whole blood (400-800 ml) before initiating standardized cardiopulmonary bypass. All of them had balanced anesthesia with thiopental, fentanyl, midazolam, atracurium and nitrous oxide in oxygen. After heparin reversal, PRP/PRP and autologous blood were reinfused in groups II and III, respectively. Recording of hematocrit, blood loss as well as the total number of transfusion was performed. In three groups, significant low levels of hematocrit were seen after cardiopulmonary bypass. Groups II and III has less blood loss after the operation as well as less banked blood and blood products transfusion (p<0.05). In conclusion, the reinfusion of PRP/PRP and autologous blood may serve as an effective method for reducing the amount of banked blood and blood products given in transfusion following cardiac operation.