FTIR monitoring of the 13-valent pneumococcal conjugate vaccine for lung cancer patients: Changes in amides vibrations correlated with biochemical assays.

Lung cancer is one of the most lethal cancers. Unfortunately, respiratory tract infections are very common in lung cancer patients, delaying appropriate anticancer therapy. To increase therapy efficiency, in this study we examined the effect of 13-Valent Pneumococcal Conjugate Vaccine on the immune response in lung cancer patients, which indirectly affects the success of anticancer therapy. The study was done using biochemical tests and Fourier Transform InfraRed (FTIR) spectroscopy. For this purpose, serum from lung cancer patients aged 52 ± 9 years (III and IV clinical stage; 79 %; n = 103) before and seven as well as 30 days after vaccination was collected. Obtained results showed increasing concentrations of immunoglobulin IgG and IgG2 groups in patients after vaccination in comparison with group before vaccination. This result was confirmed by FTIR spectroscopy, where higher absorbances of amides vibrations were observed after vaccination. Interestingly, lack of differences in the amides absorbances between patients 7 and 30 days after vaccination were noticed. FTIR spectra also showed changes in the ratio between amide I and amide III as well as between amide II and amide III in the groups of patients after vaccination. From deconvolution of made I range (1600 cm^-1-1700 cm^-1) decrease of the ratio between α-helix and β-sheet around 0.05 was noticed in serum collected from patients after vaccination in comparison with patients before vaccination. Using Principal Component Analysis (PCA) analysis of FTIR data it was observed that serum collected from all three analyzed groups of samples was possible to differentiate. The highest accuracy in differentiation group of samples before and 7 days after vaccination was visible in amide I, while before and 30 days after vaccination using amide II. Correlation between immunoglobulin IgG and IgG2 concentrations obtained by biochemical assays and FTIR were noticed only in the group of serum collected 30 days after vaccination, which suggested that FTIR spectroscopy reflects biochemical data.