[Activity of the caspase-3 in the culture of peripheral blood mononuclear cells stimulated with Borrelia burgdorferi antigens].

OBJECTIVE

To investigate whether the decreased rate of apoptosis of peripheral blood mononuclear cells occurs in patients with chronic Lyme arthritis (LA), which could contribute to persistent inflammation in those patients.

METHODS

PBMC from 7 patients with LA and 6 healthy persons (control--C) were incubated for 48 hours without stimulation (negative control) or under antigenic stimulation with Borrelia burgdorferi s.l. spirochetes: Borrelia afzelii VS46110 (B.a.), B. garinii 20047 (B.g.) or B. burgdorferi sensu stricte B-31 (B.ss.). Concentration of the apoptosis mediator active caspase-3, was measured by ELISA in the culture homogenate.

RESULTS

Mean active caspase-3 concentration was higher in LA than in C in unstimulated culture. Increase of active caspase-3 concentration under antigenic stimulation occurred in C (significant for B.g.), but not in LA.

CONCLUSIONS

1) apoptosis rate of PBMC increases in presence of B. burgdorferi s.l., which may be a defense mechanism of this pathogen; 2) in late LA there is increased baseline susceptibility of PBMC to apoptosis, but exposition to B. burgdorferi s.l. seem not to exert further pro-apoptotic effect. This altered response to pro-apoptotic stimuli may be related to persistent inflammatory pathology in this group of patients.