Human parvovirus B19 in patients with beta thalassemia major from Tehran, Iran

BACKGROUND: Due to the tropism of human parvovirus B19 to erythroid progenitor cells, infection in patients with an underlying hemolytic disorder such as beta-thalassemia major leads to suppression of erythrocyte formation, referred to as transient aplasia crisis (TAC), which may be life-threatening. We investigated the prevalence of parvovirus B19 among patients with beta thalassemia major attending the Zafar Adult Thalassemia Clinic in Tehran, Iran. METHODS: This cross-sectional study was performed to determine the presence of parvovirus B19 DNA in blood samples and parvovirus B19 genotypes in plasma samples of patients with thalassemia major. The population consisted of 150 patients with beta-thalassemia major who attended the Zafar clinic in Tehran. Specimens were studied using a real-time polymerase chain reaction assay. RESULTS: The prevalence of parvovirus B19 in our study population was 4%. Of 150 patients with thalassemia, six (4%) were positive for B19 DNA. There was no significant correlation between blood transfusion frequency and B19 DNA positivity. Finally, phylogenetic analysis of human parvovirus B19 revealed genotype I in these six patients. CONCLUSION: In this study, acute B19 infections were detected in patients with beta thalassemia major. Screening of such high-risk groups can considerably reduce the incidence and prevalence of B19 infection; thus, screening is required for epidemiologic surveillance and disease-prevention measures.

Variations in intraplatelet phospho-VASP expression due to pre-analytical sample preparations, illustration of a quality control issue in platelet pharmacology

Intraplatelet vasodilator-stimulated phosphoprotein [VASP] analysis is a commonly used laboratory approach for monitoring of the anti-platelet therapy with adenosine diphosphate [ADP] receptor blocking agents; however, it's testing in clinical laboratory needs a high level of experience and proficiency. The ability to recognize how the pre-analytical variations can change the results would be helpful for the interpretation of data from intraplatelet VASP analysis. The aim of this study was to describe the possible differences of intraplatelet phospho- VASP expression between washed and platelet rich plasma [PRP] samples, both at baseline levels and following experimentally induction of VASP phosphorylation. PRP and washed platelet samples were treated with different inducers of VASP phosphorylation, including forskolin [10 micro M], prostaglandin E1 [PGE1] [50 nM] and sodium nitro-prusside [SNP] [100 micro M]. Untreated PRP and washed platelet samples were also included in study as baseline controls. After labeling of platelets with either anti P-Serine157-VASP or anti P-Serine239-VASP, the samples were subjected to flow cytometric analysis to monitor the levels of intraplatelet phospho-VASP expression. Washed platelet samples tend to show increased expression of intraplatelet P-Serine[157]- VASP at baseline state and also more expression of P-Serine[157]-VASP and P-Serine[239]-VASP in response to forskolin and SNP, compared with PRP samples. Though, reduced levels of PGE1- induced VASP phosphorylation at both residues were detected for washed platelets. In this study we have provided some background information required for performing of intraplatelet VASP analysis on differently handled platelet samples and interpretation of the obtained results

Frequency & specificity of RBC alloantibodies in patients due for surgery in Iran.

Background & objectives: Red blood cell alloimmunization is common in patients receiving multiple blood transfusions. Since the probability of repeat transfusion increases with longer life expectancy, it is important to study to which extent alloimmunized patients with a history of transfusion are prone to form alloantibodies after transfusion events. The aim of this study was to retrospectively analyze the alloimmunization against RBCs among transfused patients who were to undergo elective surgery in Tehran, Iran. Methods: A total of 3092 occasionally transfused patients, who were to undergo elective surgery, in four hospitals in Tehran were included in the study. For patients with alloantibodies, the data about sex, date of birth, history of transfusion, surgery, abortion and alloantibody specificity were collected. Results: Clinically significant alloantibodies were found in 30 patients. The presence of positive antibodies in the patients for whom cross-match had been done was one per cent. Most of them had surgery history or transfusion record during the preceding year. The three most frequent alloantibodies were anti-K (23.53%), anti- E (20.59%) and anti-c (17.56%). Interpretation & conclusions: The most common clinically significant alloantibodies identified in men and women were anti-K and anti-E, respectively. The most common causes of alloimmunization for men were surgery history and transfusion record and for women pregnancy.