720 LYMPHOCYTOTOXIC ACTIVITY OF ANTI-KLEBSIELLA

(ABSORBED WITH

36

DIFFERENT KLEBSIELLA

427

SERUM

ISOLATES)

FOR

LYMPHOCYTES OF PATIENTS WITH A.S.

F28) of the thirty-six isolates of Klebsiella tested are capable of removing the lymphocytotoxic activity (as determined by the 5’Cr release test)5 of anti-Klebsiella 427 serum for A.S.+ B27+ lymphoid cells. This finding suggests that about 8( of randomly selected isolates of Klebsiella, derived from sputum, fseces, and urine, are capable of cross-reacting with a specific B27-associated gene product on the lymphoid cells of patients with A.s. To strengthen the observation that isolates F19 and F28 were antigenically related to 427, antisera were produced in rabbits to these two isolates and found to be specifically cytotoxic for the cells of B27+ patients with A.s. but not for cells of B27+ or B27- healthy individuals (results not shown). It remains to be determined whether the three isolates (427, F19, F28), which all react with a specific membrane component on A.S.+ B27+ lymphocytes, also have identical serotypes.

Nelly Coulits

for technical

an

earlier pregnancy, but

not

associated with her

current joint pains. She had active synovitis of the second and third metacarpophalangeal joints on the left, both wrists, both ankles, all her metatarsophalangeal joints and her left knee which had a warm tender effusion. Her spine had a full range of movement. A clinical diagnosis of rheumatoid arthritis was made but culture of the synovial aspirate from her left knee grew Klebsiella spp. and a repeat aspirate 4 days later grew the same

organism. Her white-blood-cell count at the time of the first joint aspiration was 4500 (64