The Characteristics of Residual Leukocyte in Sepacell PLS-5A Filtered Platelet Concentrates / 대한혈액학회지

BACKGROUND: We evaluated residual leukocytes characteristics of white cell(WBC) reduction filter in platelet concentrates. Differential count and lymphocyte subset changes were measured before and after leukocyte filtration in platelet concentrates. MATERIAL AND METHODS: Ten units of platelet concentrates were prepared and were filtered with WBC-reduction filter(Sepacell PLS 5A, Japan). After filtration of blood products, WBC and differential leukocyte count and lymphocyte subsets were counted by microscopic examination of Wright-Giemsa stained smear and Facscan(Becton-Dickinson, USA). Monoclonal antibodies used for lymphocyte subset test were CD3(FITC), CD4(FITC), CD8(PE), CDl4(PE), CDl6(PE), CDl9(PE), CD33(PE), CD56(PE), IgGl(FITC), IgG2(PE). RESULTS: The main population of residual leukocytes after filtration was mainly lymphocytes(96.7%), and CD3 positive T lymphocytes showed 23.8% positivity of residual leukocyctes and the next were NK cell(8.7%). B lymphocytes were rarely found(<0.01%) and CD4/ CD8 ratio was within normal limits. CONCLUSION: The leukocyte reduction filters(Sepacell PLS-5A) would be effective for prevention of platelet alloimmunization but not sure about the effect for prevention of TA GVHD.

Genotypes of Circumsporozoite of Plasmodium vivax in Korea / 대한임상병리학회지

BACKGROUND: More than 200 million people suffer from malaria worldwide. In Korea this infectious disease had been on a decreasing trend since 1930s and was considered to be eradicated from 1985. However, since 1993 when a case of malaria was reported, its incidence is progressively increased. Recent efforts have been focused on the development of vaccine against the infective sporozoite stage of Plasmodium vivax. It has been found that sporozoites are complicated with genetic variation within the circumsporozoite gene and phenotypic heterogeneity in the protein it encodes. So, we investigated the distribution of circumsporozoite gene of Plasmodium vivax in Korea. METHODS: Polymerase chain reactions (PCR) were performed on samples confirmed with microscopic examination for P. vivax and negative samples with clinical and microscopic examination. The amplified products were analyzed by dot hybridization with oligonucleotide probes VK210 and VK247 which are respectively complementary to the predominant and variant strains of the circumsporozoite gene of P. vivax. RESULTS: The incidence of isolation in VK210 and VK247 strains were 96.3%, respectively and individuals who were infected with both strains were 92.7%. Compared to the microscopic examination, the results of PCR showed 82% in sensitivity, 100% in specificity. CONCLUSIONS: The present study suggests that a single-epitope vaccine based on either one circumsporozoite domain is unlikely to be protective because both VK210 and VK247 strains of P. vivax were found widely in Korea. The PCR method appears not to be feasible as a screening, but suitable as a confirmatory test for the identification of Plasmodium species.

Evaluation of COBE Spectra "Leukocyte Reduction System (LRSTM)" for the Production of Leukocyte-Reduced Platelets / 대한수혈학회지

BACKGROUND: Leukocytes have been shown to be an undesirable contaminants in platelet transfusions because these contaminants may develop various adverse consequences. Current platelet products by plateletpheresis are heavily contaminated with leukocytes. Recently, new platelet apheresis system (COBE Spectra LRSTM) was designed to make it possible to collect platelets with very low leukocytes contamination. We evaluated the COBE Spectra LRSTM by comparing it with COBE Spectra. METHODS: Plateletpheresis procedures were performed on 75 normal donors; 45 procedures for COBE Spectra LRSTM and 30 procedures for COBE Spectra. We evaluated platelet yields, processing times, efficiency, and leukocytes content on two apheresis machines. RESULTS: Comparative results of COBE Spectra LRSTM with COBE Spectra were as follows: the mean processing time per unit was 97 min and 91 min, the efficiency per unit was 38.4 +/- 11.5% and 46.9 +/- 12.1%, the mean leukocytes contamination per unit was 6.1x104 and 2.1x106 respectively (p0.05). CONCLUSIONS: Platelet collections with COBE Spectra LRSTM demonstrated comparable platelet yields and strikingly low WBC contamination. This study indicate that the COBE Spectra LRSTM is an efficient and reliable system for the collection of platelets with very low residual WBC levels. It seems that leukocyte reduction filter for platelet products by COBE Spectra LRSTM is not necessary for further removal of leukocytes to prevent alloimmunization, non-hemolytic transfusion reactions, certain viral and bacterial infections.

Evaluation of the Use of Rh(D)'Control Test in Rh(D) Typing / 대한수혈학회지

Clinically, the Rh blood group system is important since Rh antibodies are readily induced by transfusion or pregnancy in individuals negative for the antigert and may cause hemolytic reactions or hemolytic disease of the newborn. Since the D antigert is strongly immunogenic, donors and patients are routinely typed for D status and patients are generally given D compatible blood. But under several circumstances such as spontaneous agglutination of red blood cells coated with immunoglobulin, antisera with additives may cause false positive results in test using high-protein reagents. And facton in the patient' s own serum may also affect the test, since unwashed red blood cells suspended in their own serum or plasma are frequently tested. Therefore, manufacturers and American Association of Blood Banks(AABB) recommend that the Rh(D) control test with Rh(D) control reagent which contains the same additive present in high-protein anti-D except for the anti-D. This study was undertaken to evaluate the usefss of the Rh(D) control test in Korea where Rh(D) negative population is small. Red blood cells from 1115 in-patients and 468 out-patients at Korea University Medical Center were employed in Rh(D) typing and Rh(D) control test in parellel. 1580 cases are Rh(D) positive and 3 cases were Rh(D) negative. No agglutination was observed with Rh(D) control test. Though AABB and manufacturers recommended that the Rh(D) control test should be done in parellel with Rh(D) typing test, the authers concluded that there were no need to run the Rh(D) control test in Korea.