Since immune responses play a major role in the development of connective tissue diseases, it is not surprising that a number of laboratory studies reflect these responses. Prior to the 1940s when rheumatoid and LE factors became widely known, one relied mainly on erythrocyte sedimentation rate and serum electrophoresis to identify protein abnormality. Elevated sedimentation rate depends on rouleaux formation, and rouleaux formation is dependent upon large asymmetric molecules of fibrinogen and gamma globulin in plasma. The demonstration of gamma globulin has become the cornerstone of the immunologist’s edifice. It is amazing to see how the subspecialty of immunology has mushroomed to involve the many facets of disease processes such as connective tissue diseases, skin diseases, gastrointestinal diseases, renal diseases, and cancer. More recently, immune deficiency diseases have included the pediatrician in the ever-enlarging field of immunology as has the modern-day discovery of human leukocyte antigen (HL-A) testing and tissue typing included the geneticist
