Alteration of Lactate Dehydrogenase Isoenzyme Pattern Observed from CSF in Patients with Meningitis by Streptococcus pneumoniae / 대한진단검사의학회지

The bacterial protein streptokinase binds to LD-M subunits, which shares a small region of homology with the site on plasminogen to which streptokinase is known to bind. We found an extra band of LD activity in CSF in a patient, suffering from meningitis due to Streptococcus pneumoniae. We performed a LD isoenzyme electrophoresis of the serum mixed with supernates from cultured broth of several species of streptococci. To investigate the effect on serum LD activity, we analyzed LD activity after the mixing of the serum with products of S. pneumoniae. S. pneumoniae, groups A and C beta hemolytic streptococci, revealed the extra band of LD activity at the origin site. The supernates of cultured broth of S. pneumoniae inhibited LD activity of the serum. Streptokinase or streptokinase-like substances can form complexes with LD in vivo after streptococcal infection, with consequent alteration of the LD isoenzyme pattern.

Study on LD Isoenzyme Activity in Synovial Fluid of Joint Diseases / 대한정형외과학회잡지

The authors investigated LD activity and isoenzyme of total serum and joint fiuid in 18 cases of rheumatoid arthritis, 11 cases of degenerative arthritis, 6 cases of traumatic arthritis, and 10 cases of healthy control. The samples of serum examined were obtained from the anterior cubital vein and joint fluid from the knee joint except 2 cases of the rheumatoid arthritis, which were obtained from the wrist joint, in Busan National University Hospital from the April to July 1981. Total serum LD activity was measured by method of Caboud-Wroblewski and isoenzyme fractions were analysed by cellulose acetate electrophoresis. The results obtained were as follows: l. In the patients with joint diseases, total serum LD activity was significantly increased than that of healthy control. 2. The LD1 isoenzyme of joint fiuid was increased in degenerative arthritis than that in rheumatoid arthritis, and LD3 and LD5 isoenzymes were significantly increased in rheumatoid arthritis than that in degenerative arthritis. 3. In correlation between total LD and LD isoenzymes activities in joint fluid, total LD activity of rheumatoid arthritis was correlated with decrease of LD1 isoenzyme and increase of LD5 isoenzyme activity, and total LD activity of the degenerative arthritis was correlated with increase of LD1 isoenzyme activity. 4. In correlation between isoenzyme activity and gamma globulin of joint fluid, LD3 and LD5 isoenzyme activity in rheumatoid arthritis and LD4 in degenerative arthritis was correlated with increase of gamma globulin.