Table 2.

Comparison between fresh and frozena PBMC for their proliferative responses to B. pertussis antigens in 48-month-old children

AntigenLymphoproliferative responseb
CMI+CMI
FreshFrozenFreshFrozen
None0.5 ± 0.10.35 ± 0.070.4 ± 0.00.2 ± 0.05
PT21.4 ± 1.332.7 ± 5.72.8 ± 1.12.1 ± 1.5
PRN16.9 ± 2.435.2 ± 9.91.1 ± 0.40.7 ± 0.1
FHA12.1 ± 1.818.3 ± 0.80.8 ± 0.10.4 ± 0
BPc 10.0 ± 2.320.1 ± 6.01.3 ± 0.01.7 ± 0.3
  • a Fresh and frozen PBMC from four children (two CMI+ and two CMI) were assayed for proliferation as described in Materials and Methods and in the legend to Table 1.

  • b Expressed as mean (triplicate samples from both children) ± SE of thymidine incorporation values (103 cpm).

  • c B. pertussis cells (strain 18323; ATCC 9797) were heat inactivated (96°C; 1 h) and used at a concentration of 106 CFU/ml.