Molecular and Serological Assessment of Chronic Parvovirus B19 among Chronic Hemolytic Anemia Children

Abstract

Background: Parvovirus B19 infections can suppress erythropoiesis and induce acute erythroblastopenia which is often referred to as transient aplastic crisis with hematological disorders especially chronic hemolytic anemia. Objectives: to detect the presence of parvovirus B19 (B19) DNA together with its IgG antibodies in the sera of children with chronic hemolytic anemia and in apparently healthy children in Menoufia University Hospitals and to detect the prevalence of chronic parvovirus B19 infection through detection of PCR among positive anti-parvo virus B19 IgG in different types of anemia. Methodology: The study was conducted on 60 children with chronic hemolytic anemia (40 children with chronic hemolytic anemia without a history of aplastic crisis and 20 children with chronic hemolytic anemia with a history of aplastic crisis) and 20 age and sex-matched apparently healthy children. All patients were subjected to full history taking, clinical examination and laboratory investigations. The presence of B19 IgG levels were measured by using anti-parvovirus B19 ELISA kits (EUROIMMUN), as well as detection of its DNA by nested-polymerase chain reaction technique. Results: Anti-parvovirus B19 IgG antibodies were detected in 62.5% and 100% of patients in group I and group II respectively. Only 20% in control group had a detectable level of anti-parvovirus B19 IgG. There were significant positive correlations between age of patients, frequency of transfusion, and transfusion index in both groups and the level of anti-parvovirus B19 IgG. Seven B19 IgG seropositive cases (14.3%) had B19 DNA. Although78% of children with f thalassemia major had a detectable level of anti- parvovirus B19 virus IgG antibodies, only 15.4% of them had B19 DNA. Children with sickle cell anemia were presented only in group II with aplastic crisis by percentage of 25%, where the prevalence of anti-B19 IgG antibodies among them was 100% but only one child had both anti-B19 IgG antibodies and B 19 DNA (20%).Patients who had anti- parvo virus B19 IgG and those who had both B19 DNA anti-parvo virus B19 IgG cases had a higher transfusion index compared to negative cases. Conclusion: All children with hematological disorders must be screened for B19. Direct detection of DNA by PCR needs to be performed along with serology in these children. Genotyping and quantification of the virus can be more useful for diagnosis and staging of infection.