SOME NOTES ON SERUM LDH ANOMALY
Seven examples of LDH isozyme anomaly were encountered for the past three years through screening 2,572 patient's sera submitted to our laboratory for routine chemical study. The sera with abnormal LDH isozymes were from the patients with multiple myeloma (3), chronic hepatitis (2), encephalomalacia (1) and coronary insufficiency (1). The abnormality (electrophoretically slow, fast, deleted or split) was related to LDH-2, LDH-3, or LDH-4 isozymes, and immunoelectrophoresis combined with LDH-staining revealed its cause to be conjugation of immunoglobulin (Ig-G or Ig-A) of κ-type with the relevant LDH isozymes (LDH-2, LDH-3, LDH-4). Participation of immunoglobulins of λ-type in formation of abnormal LDH isozyme was never encountered, κ-type light chain may constitute an arm which grips LDH subunit when immunoglobulin conjugates with LDH. IgM was not concerned with LDH anomaly, probably because it is too large or inadequate for conjugation with LDH molecule.