[Value of anti hemolysin and anti-gammahemolysin assays for the diagnosis of staphylococcal infections, particularly of osteoarthritis (author's transl)].

The authors report the results of more than twelve years' personal research on the value of anti-alphahemolysin (AASTL) and antigammahemolysin (AGSTL) assays for the diagnosis of staphylococcal infections, and particularly of osteoarthritis. Among 574 controls, AASTL levels exceeded 2 IU in only 14 subjects (11 of these, levels were between 2 and 3 IU). Levels less than, or equal to, 2 IU were therefore considered normal. This is consistent with previously published data. In 144 staphylococcal infections, confirmed by bacteriology, an increase in AASTL was found in 95 of all cases (65.9%) and in 54 of the 76 osteoarthritis' (71%). Similarly, AGSTL titres, which were under 1/160 (upper normal limit) in 138 controls, were increased in 35 patients with unequivocal staphylococcal infections (61.4%), and in 25 of 36 patients with osteoarthritis (69.4%). These results show that AASTL assay is reliable and often abnormal. However, assay of both hemolysins yields even better results. This dual assay was performed in 57 patients with staphylococcal infection. One hemolysin at least was increased in 47 patients (82.4%). This represents additional positivity in 15.7% of patients when compared to AASTL assay alone, and in 21% when compared to AGSTL assay alone. The high level of positive results with dual assay is even more striking when only staphylococcal osteoarthritis is considered: one or both hemolysins were increased in 91.1% of these patients (31/34).