Genotyping of Dombrock and Lutheran blood group systems in blood donors from the southwestern region of the state of Paraná, Southern Brazil

Abstract Background Lutheran and Dombrock are two blood group systems with low immunogenic antigens; they can cause mild-to-moderate transfusion reactions. For both, immunophenotyping is not performed in the pretransfusion routine in Brazil. In addition, the distribution of their antigenic frequencies is an important marker of ethnicity. Thus, the goal of this study was to carry out the genotyping of the LU*01, LU*02, DO*01 and DO*02 alleles of the Lutheran and Dombrock blood group systems in blood donors from the southwestern region of the state of Paraná, Southern Brazil. Method Genotyping was performed for 251 blood donors by specific allele-polymerase chain reaction. The genotype and allele frequencies were obtained through direct counting and compared with other Brazilian populations using the chi-square test with Yates correction. Results The distribution of genotype frequencies for LU were 0.4% for LU*01/LU*01, 6.8% for LU*01/LU*02 and 92.8% for LU*02/LU*02 and for DO, they were 19.9% for DO*01/DO*01, 44.6% for DO*01/DO*02 and 35.5% for DO*02/DO*02. The allele and genotype frequencies of LU and DO were similar to those expected for Caucasians, but the DO*01/DO*01 genotype frequency was different to other Brazilian populations. The rare LU*01/LU*01 genotype was found in a loyal blood donor. Conclusion The genotyping techniques allowed the evaluation of the LU*01, LU*02, DO*01 and DO*02 alleles in blood donors registered in the Hemotherapy Center of the southwestern region of Paraná, Southern Brazil, and contributed to a genotyped blood donor database.

DARC (Duffy) and BCAM (Lutheran) reduced expression in thyroid cancer.

Duffy or DARC (Duffy Antigen Receptor for Chemokines) is a glycosylated membrane protein that selectively binds angiogenic chemokines. Previous in vivo and in vitro studies of DARC function in cancer have associated DARC over expression with better prognosis, decreased metastatic potential, and inhibition of tumor-associated neovascularization. Another carcinogenesis-associated antigen is Lutheran or BCAM (basal cell adhesion molecule), a surface glycoprotein that acts as a receptor for the extracellular matrix protein, laminin. BCAM is a protein related to tumor progression; and, its over expression is associated with skin, ovarian and pancreatic cancers. We explored DARC and BCAM functions and investigated whether or not their expressions were altered in thyroid cancer. The expression of DARC and BCAM were evaluated by quantitative real-time PCR (qPCR) in a set of 18 normal thyroid tissues (NT), 15 follicular adenomas (FTA), 17 follicular carcinomas (FTC), and 122 papillary thyroid carcinomas (PTC), including 78 classical (CVPTC) and 44 follicular variant (FVPTC). RNA was isolated, reverse transcribed to cDNA, and used in qPCR reactions containing SYBR Green. The relative expression value was calculated using ribosomal protein S8 as an internal control. When we compared benign (NT and FTA) versus malignant samples (FTC, CVPTC and FVPTC) we observed a significant decrease of DARC and BCAM relative expression in malignant cases. Additionally, we correlated clinic-pathological features (tumor size, presence of metastasis, presence of lymphocyte infiltrate) with DARC and BCAM expression. We found a diminished expression of DARC in PTC samples, which was correlated with tumor size and presence of a lymphocyte infiltrate. We, also, found a correlation between decreased BCAM expression and tumor size or presence of metastasis. DARC and BCAM expression was associated with pathogenesis of thyroid carcinoma and correlated with clinical-pathological features.

Presença de anticorpo anti-Lutheran B em paciente com leucemia linfóide aguda / Anti-Lutheran B in a patient with acute lymphoblastic leukemia

Leucemias agudas necessitam de suporte hemoterápico para serem tratadas adequadamente. A presença do anticorpo anti-Lutheran B e a alta freqüência do antígeno em nossa população dificulta o tratamento de doenças hematológicas que necessitam de suporte transfusional, tais como a leucemia linfóide aguda (LLA). Alternativas de tratamento hemoterápico são abordadas neste artigo. Descreve-se o caso de uma paciente com LLA e anticorpo anti-Lutheran B. A dificuldade em encontrar sangue compatível levou os autores a adotarem estratégia conservadora no tratamento hemoterápico. O uso de eritropoetina e a adoção de protocolo quimioterápico individualizado viabilizaram os resultados obtidos.

Acute leukemia needs hemotherapeutic support to be successfully treated. The Lutheran B antibody, specifically the high frequency of this antigen in our population, has made it difficult to treat hematological malignancies that need transfusional support, including acute lymphoblastic leukemia. Finding compatible blood is complex and so the authors adopted a conservative treatment strategy. The prescription of epoetin and an individualized chemotherapy protocol may improve results. We describe a case report of a patient with anti-Lutheran B antibody and how difficulties to find compatible blood were solved.

Therapy with hydroxyurea is associated with reduced adhesion molecule gene and protein expression in sickle red cells with a concomitant reduction in adhesive properties.

Propagation of the vaso-occlusive process in sickle cell anaemia (SCA) is a complex process involving the adhesion of steady-state SCA patients red cells and reticulocytes to the vascular endothelium. The effect of hydroxyurea therapy (HUT) on the adhesive properties of sickle cells and the expression of adhesion molecule genes by erythroid cells of SCA individuals is not yet fully understood. The expressions of the CD36 gene and the VLA-4-integrin subunit genes, CD49d (alpha-subunit) and CD29 (beta-subunit), were compared in the reticulocytes of steady-state SCA patients and patients on HUT using real-time PCR. Basal adhesion of red cells from these subjects was also compared using static adhesion assays, as was surface protein expression, using flow cytometry. Basal sickle red cell adhesion to fibronectin was significantly greater than that of normal cells (P < 0.01); in contrast, HUT was associated with significantly lower levels (P < 0.01) of red cell adhesion that were similar to those of control cells; this decrease could not be justified solely by altered reticulocyte numbers in this population. Accordingly, flow cytometry demonstrated that reticulocytes from patients on HUT had significantly lower CD36 and CD49d surface expressions (P < 0.01) and, importantly, significantly lower expressions of the CD36, CD49d and CD29 genes (P < 0.05) than reticulocytes of SCA patients not on HUT. Taken together, data support the hypothesis that HUT reduces the adhesive properties of sickle cells and that this decrease appears to be mediated, at least in part, by a decrease in the gene and, consequently, surface protein expression of adhesion molecules such as VLA-4 and CD36.