Control of viability, thermostability and residual virulene of BCG vaccines. Multiple comparison of laboratory data to select products for immunostimulation in the treatment of cancer.

UNLABELLED

The aid of the work was to apply the multiple comparison method to select BCG products for immunostimulation. In the IABS-BCG Collaborative Study 1973 program coded BCG products (code) and reference preparation were investigated with 3 laboratory tests to compare differences concerning: (1) viability = viable units E6/ml (VU) of vaccines stored at 4C, (2) 37C thermostability (TS) slope = daily VU decrease of vaccines stored at 37C/0, 7, 14, 21, 28 days, (3) relative persistence capacity (RPC),--residual virulence--of the BCG strains in the mice spleen; regression followed up to 360 days. Culturable particles and recoverable VU were determined on BOAA medium. Means and regression coefficients of VU, TS and RPC were ranked after analysis of variance and evaluated by multiple-comparison-Gabriel method. Figures summarize the results. As to VU the products form 3 subsets; as to TS the products are in two subsets (ie potency of several products could be included in the same subset). Thus, the ranks of VU and TS are not the same. Also there are differences among overall rank of RPC (coefficient concordance of ranks of 2 VU doses, log and sqrt transformation of exp. data) and the VU as well as the TS.

CONCLUSION

parallel VU, TS and RPC investigations and multiple comparison method could ensure the validity and reliability of the estimations in the quality control of products for immunostimulation and could explain the correlations and contradictions between the laboratory data and the results of the clinical trial in neoplasia.