Cytokine and immunoglobulin concentrations in cervical secretions: reproducibility of the Weck-cel collection instrument and correlates of immune measures

Elucidation of local immune response at the cervix is important for underst anding and evaluating STD vaccine approaches currently being proposed. Howe ver, no well-validated method exists for the collection of cervical secreti ons for evaluation of cervical immune response. The purpose of this study w as to determine the reproducibility of the Weck-cel sponge used to collect cervical secretions for immunological assessment. Additionally, it was poss ible to examine correlates of immunity as part of our investigation. Two ce rvical secretion specimens were collected sequentially from each of 120 wom en using Weck-cel sponges. Cervical secretions were collected prior to Pap smear sampling to avoid blood contamination, At the laboratory, the duplica te specimens were weighed and tested in replicate wells to determine the co ncentration of two cytokines (IL-10 and IL-12) and two immunoglobulin isoty pes (IgG and IgA). IL-12, total IgG, and total IgA showed a strong correlat ion between samples from the same woman ranging from 0.78 to 0.84. Kappa co efficients obtained after categorizing assay results ranged from 0.62 to 0. 67. Variance components analysis suggested that 69% to 85% of the variance observed was accounted for by between-women variance, with the remaining va riability attributed to variation between samples collected from the same w oman. IL-10 results were less reproducible than those obtained from the oth er assays examined, suggesting problems with the assay used to measure this cytokine rather than with the Weck-cel sampling instrument. Various factor s were found to significantly correlate with cytokine and immunoglobulin me asures at the cervix. Age and reproductive status were associated with all four immune measures; women over 50 years of age and those who were postmen opausal had increased concentrations of IL-10, IL-12, IgG, and IgA. Hemoglo bin concentrations were positively correlated with IgG and IL-10 concentrat ions, but not with IgA or IL-12 concentrations, suggesting local production of IgA and IL-12. The concentration of all immune measures decreased with increasing volume of collection. No significant association was observed be tween time from collection to freezing of specimens and concentrations of c ytokines or immunoglobulins. Overall, our data suggest that measurement of immunological parameters in cervical secretions collected using Weck-cel sp onges are reproducible. In addition, various correlates of cytokine and imm unoglobulin concentrations were identified. (C) 1999 Elsevier Science B.V. All rights reserved.