Characteristics of acute glomerulonephritis associated with human parvovirus B19 infection

BACKGROUND: Acute glomerulonephritis (AGN) is a rare complication of human parvovirus B19 (HPB19) infection. The clinical and pathological features of AGN associated with HPB19 (HPBAGN) have not yet been fully elucidated. METHODS: We analyzed 10 HPBAGN cases, focusing on their clinical and serological features. We also performed histopathological examinations of renal biopsy specimens obtained from three of the 10 patients on day 15, 19 and 23, respectively, after the onset of symptoms. The phenotype of the glomerular infiltrating leukocytes in HPBAGN was determined by immunohistochemical staining and compared with that of glomerular infiltrating leukocytes in poststreptococcal AGN (PSAGN) and lupus nephritis. RESULTS: The clinical course and laboratory data of the HPBAGN patients revealed female preponderance (male = 0, female = 10), erythema in 9 of the 10 patients, leukopenia in 3, positive antinuclear antibody titer in 4, hypocomplementemia with low levels of C3, C4, and CH50 in 9, and liver dysfunction in 7. Endocapillary hypercellularity of leukocytes was demonstrated in all three patients who underwent renal biopsy. In comparison with PSAGN and lupus nephritis with crescents there were less neutrophil in HPBAGN compared to marked macrophage infiltrates that were equally intense in both the control and the HPBAGN group. CONCLUSIONS: Our findings indicate that HPBAGN is characterized by female preponderance, erythema, leukopenia, positive antinuclear antibody titer, and hypocomplementemia, and that minor neutrophil infiltration may be related to mild clinical manifestations despite the marked fixation of glomerular leukocytes in HPBAGN.