Burdon D W
Immunology. 1971 Aug;21(2):363-8.
The immunoglobulins of normal human urine, collected per urethram, and by supra-pubic needle aspiration have been investigated. IgD has been demonstrated in normal urine in addition to IgG and IgA. IgM was not present. Urine collected from the bladder by needle aspiration contains less secretory IgA than urine collected per urethram, but does not appear to differ from urine collected per urethram in its content of serum type IgA or of IgG. Urine collected from four male and four female subjects in two fractions contained significantly more IgA in the first fraction than in the second fraction, but the IgG content of the two fractions was similar. It is estimated that about half of the secretory IgA in normal urine originates from the urethra, and that urethral secretions do not contain appreciable amounts of IgG.