抄録
A case of lactate dehydrogenase (LDH) anomaly is reported. The patient is a 43-year-old female with mild subarachnoid hemorrhage. There are no abnormal findings on liver and heart functions. Her serum LDH activity has elevated persistently (1,050-1,100 Wroblewski units). Celloseacetate electrophoresis showed that LDH2 and LDH3 were bridging and that 86% of the total activity was found in LDH2-3. On gel filtration through a Sephadex G-200 column, the activity was recovered in two fractions, macromolecular LDH eluted from the column somewhat after “M” fraction and normal LDH eluted after “G” fraction. LDH activity was stained overlappingly on a part of IgA precipitin lines on agarose gel immunoelectrophoresis using antisera against human whole sera and IgA globulin followed by specific stainning for LDH activity. LDH zymogram was not altered by mercaptethanol reduction and LDH-IgA complex dissociated by acidification (pH 3.4), therefore the linkage is a hydrogen bond rather than a S-S bond. The patient's serum IgA, dissociated from LDH by acidification, reacted with normal LDH1-5 to make macromolecular LDH and reacted also similarly with dog and rabbit LDH.
It might therefore be assumed that the patient's own LDH was normal and that the abnormal LDH pattern was due to the presence of an abnormal IgA.
