Detection of immunoglobulin G and A antibodies to rubella virus in urine and antibody responses to vaccine-induced infection

Abstract

Urine and serum samples from 89 healthy volunteers and three healthy individuals who underwent rubella vaccination were tested for immunoglobulin G (IgG), IgA, and IgM to rubella virus (RV) by enzyme-linked immunosorbent assay methods. Subjects with positive (n = 68) or negative (n = 21) results for serum IgG were exactly the same as those with the corresponding results for urinary IgG. Both urinary and serum IgG levels remained elevated from the 3rd or 4th week after vaccination until the end of the study. Both urinary IgA and serum IgM levels tended to increase rapidly between the 3rd and 5th week and then gradually decrease until the end of the study, but the levels of both remained positive except for one sample each at the end (26th week). On the other hand, the ratio of anti-RV IgA titer to anti-RV IgG titer in urine (urinary anti-RV IgA/IgG ratio) increased rapidly between the 3rd and 4th week after vaccination and then rapidly returned to the ratio levels of the subjects positive for serum IgG from among the healthy volunteers. In summary, detection of urinary anti-RV IgG should be useful for screening for previous RV infection, and measurement of urinary anti-RV IgA/IgG ratio might be useful for diagnosing recent infection.

FIG. 1

Levels of urinary IgG and IgA antibody to RV in healthy volunteers. The division of subjects into positive and negative groups was based on serum IgG levels. Horizontal lines indicate the cutoff value. (A) Urinary IgG level; (B) urinary IgA level.

FIG. 2

Changes over time in anti-RV antibody levels in urine and serum after vaccination. Changes over time in titers of urinary IgG (A), urinary IgA (B), serum IgG (C), and serum IgM (D) against RV are indicated. •, positive sample; ○, negative sample. Samples with indeterminate values in serum assays were classified as positive. Dashed portions of the curves indicate failure to collect a sample. Horizontal lines indicate cutoff values. Circles, squares, and triangles correspond to three subjects.

FIG. 3

Changes over time in ratios of the titer of IgA antibody to RV to the titer of IgG antibody to RV in urine after vaccination, compared with the ratios for IgG-positive subjects (PS) from among the healthy volunteers. Closed symbols, samples positive for urinary anti-RV IgG or IgA; open symbols, samples negative for urinary anti-RV IgG and IgA. Dashed portions of the curves indicate failure to collect a sample. The horizontal line indicates the cutoff value of the ratio. Circles, squares, and triangles correspond to three subjects.