Natural autoantibodies against Tamm-Horsfall glycoprotein in normal individuals in relation to age and in adult patients with kidney diseases.

IgM and IgG natural antibodies to Tamm-Horsfall glycoprotein (THP) were found in serum samples of all healthy individuals tested by the ELISA technique. The IgM anti-THP antibody level was higher in the group 1-20 years old than the IgG anti-THP. The IgG anti-THP rose with increase in age (greater than 21 years old groups) and then the IgG and IgM anti-THP activity over aging remained constant. The natural anti-THP antibodies possess a lower degree of specificity and/or avidity than induced antibodies. The antibody titers against THP determined in 61 adult patients with chronic kidney diseases was significantly lower than that in adult controls. This low level of naturally occurring THP antibodies appears to be a general phenomenon. In these patients, diminished antibody levels appeared against a panel of self (collagen, fibronectin, THP) and non self (bovine gamma globulin (BGG), ovalbumin (OVA)) antigens as compared with normal controls. The low levels of these antibodies are not associated with a concomitant drop of IgG and IgM in their sera.