Serological study on parvovirus B19 infection in multitransfused thalassemia major patients and its transmission through donor units.

BACKGROUND

Human parvovirus B19 (B19) virus is a newly recognized agent for transfusion transmitted diseases. Beta-thalassemia major patients receive a hypertransfusion regimen, hence, are prone to acquire B19 infection; moreover, B19 escapes viral inactivation methods and donor units are not tested for B19, but there are just a couple of studies globally and none from the Asian continent. Hence, a study was designed to find the frequency of B19 infection and its transmission in multitransfused thalassemia patients.

MATERIALS AND METHODS

Ninety multitransfused beta-thalassemia major (thalassemia) patients, 32 controls (age, sex matched) without any history of transfusion were enrolled. Besides the donor units were tested in B19 un-infected patients. B19 specific IgG and IgM antibodies in the sera were analyzed by ELISA (in-house), using B19 VPI and VP2 recombinant and purified antigens; additionally HBsAg and anti-HIV and anti-HCV antibodies were tested for coexisting infections.

RESULTS

Seventy-three (81%) thalassemia patients tested positive for anti-B19 IgG antibodies as compared to seven (21%) in the controls group (P < 0.01), while anti-B19 IgM antibodies were detected in 37 (41.1%) compared to two (6.2%) in the controls (P < 0.01). Mean age of the thalassemia patient was eight years (range 2 - 18 years) and B19 infection was highest in the six-to-ten year range. Seropositivity increased with the number of transfusions. Two of the four HBsAg positive and five of the seven anti-HCV IgM antibody-positive patients also had anti-B19 IgM. After a six-month follow-up, four (25%) of the 16 seronegative patients seroconverted and anti-B19 IgM antibodies were detected in their donor units.

CONCLUSIONS

Most of multitransfused thalassemics were B19 seropositive or had anti-B19 IgM; in the remaining uninfected group, B19 got transmitted through infected / IgM-positive donor units.