ABSTRACT
PROBLEM: Specific pro-inflammatory cytokine profiles in plasma may characterize women with recurrent miscarriage (RM) but the dynamics of the cytokine profiles with progressing pregnancy is largely unknown. METHOD OF STUDY: Plasma was repeatedly sampled in the first trimester from 47 RM patients. The concentrations of five cytokines including tumour necrosis factor alpha (TNF-α) were measured. TNF-α levels were correlated to carriage of five TNFA promoter polymorphisms. RESULTS: TNF-α levels increased (P = 0.014) with progressing pregnancy, with higher levels in secondary than primary RM (P = 0.042) but with no significant impact on outcome. Carriage of TNFA -863C and TNFA -1031T was associated with higher TNF-α levels, and the former was found more often in secondary than primary RM (P < 0.02). CONCLUSION: Plasma TNF-α levels increase during early pregnancy in RM women regardless of outcome, but are higher in secondary than primary RM, which may be partly genetically determined.
Subject(s)
Abortion, Habitual/blood , Abortion, Habitual/genetics , Pregnancy Trimester, Second/blood , Pregnancy/blood , Tumor Necrosis Factor-alpha/blood , Tumor Necrosis Factor-alpha/genetics , Abortion, Habitual/prevention & control , Adult , DNA Mutational Analysis , Female , Follow-Up Studies , Genetic Predisposition to Disease , Gravidity/immunology , Humans , Immunoglobulins, Intravenous/therapeutic use , Polymorphism, Genetic , Pregnancy Outcome/genetics , Promoter Regions, Genetic/genetics , Ultrasonography , Young AdultABSTRACT
The problem of fitting unidimensional item response models to potentially multidimensional data has been extensively studied. The focus of this article is on response data that have a strong dimension but also contain minor nuisance dimensions. Fitting a unidimensional model to such multidimensional data is believed to result in ability estimates that represent a combination of the major and minor dimensions. We conjecture that the underlying dimension for the fitted unidimensional model, which we call the functional dimension, represents a nonlinear projection. In this article we investigate 2 issues: (a) can a proposed nonlinear projection track the functional dimension well, and (b) what are the biases in the ability estimate and the associated standard error when estimating the functional dimension? To investigate the second issue, the nonlinear projection is used as an evaluative tool. An example regarding a construct of desire for physical competency is used to illustrate the functional unidimensional approach.
