Hidden' IgG antiglobulins in normal human serum.

Area of Science:

• Immunology
• Protein Chemistry

Background:

• Antiglobulins are antibodies that target immunoglobulins.
• Their presence and characteristics in normal serum require further elucidation.

Purpose of the Study:

• To investigate the presence and nature of hidden antiglobulins in normal serum.
• To characterize the immunoglobulin classes and active regions of these antiglobulins.

Main Methods:

• Gel filtration and ultracentrifugation of normal human serum.
• Radioassay and indirect haemagglutination techniques.
• Acid dissociation of immunoglobulin components.

Main Results:

• Hidden antiglobulins were detected in normal serum.
• Both IgM and IgG antiglobulins co-fractionated in macroglobulin peaks.
• IgG antiglobulins dissociated into 7S components under acidic conditions.
• Antiglobulin activity was confirmed to reside within the Fab region.

Conclusions:

• Normal serum contains previously undetected antiglobulins.
• These antiglobulins, of both IgM and IgG classes, are associated with macroglobulin fractions.
• The Fab fragment is the functional site of antiglobulin activity.