Serum immunoglobulin concentrations in preschool children measured by laser nephelometry: reference ranges for IgG, IgA, IgM.

Isaacs, David; Altman, D G; Tidmarsh, C. E.; Valman, H B; Webster, Alison

doi:10.1136/jcp.36.10.1193

Cited by 68 publications

(42 citation statements)

References 11 publications

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“…User-friendly functions implementing Markov chain Monte Carlo algorithms to fit the models considered were written in compiled language and incorporated into the R library DPpackage (Jara, 2007). Isaacs et al (1983) considered serum immunoglobulin G concentrations from n = 298 children aged 6 months to 6 years old. These data were further analysed by Royston & Wright (1998) and Kapitula & Bedrick (2005) using the parametric exponential normal family, which includes parameters for skew and kurtosis that can be functions of covariates.…”

Section: Applicationmentioning

confidence: 99%

A class of mixtures of dependent tail-free processes

Jara

Hanson

2011

Biometrika

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SUMMARYWe propose a class of dependent processes in which density shape is regressed on one or more predictors through conditional tail-free probabilities by using transformed Gaussian processes. A particular linear version of the process is developed in detail. The resulting process is flexible and easy to fit using standard algorithms for generalized linear models. The method is applied to growth curve analysis, evolving univariate random effects distributions in generalized linear mixed models, and median survival modelling with censored data and covariate-dependent errors.

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Section: Applicationmentioning

confidence: 99%

A class of mixtures of dependent tail-free processes

Jara

Hanson

2011

Biometrika

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“…The procedure for delivering age-related upper 99 th centile reference limits for %XCL cells observed in samples of 30, 40, 50 or 60 cells follows that used to establish age-related reference limits for serum immunoglobulins (Isaacs et al, 1983), adapted to accommodate the fact that we are dealing with counts rather than concentrations. The study subjects (n = 655) were grouped by age into nine intervals, for each of which the proportion of XCL cells was recorded along with the corresponding median age.…”

Section: Statistical Analysesmentioning

confidence: 99%

X chromosome loss and ageing

Russell

Strike

Browne

et al. 2007

Cytogenet Genome Res

175

145

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The detection of a low level 45,X cell line during routine cytogenetic analysis in an adult female can be difficult to interpret. In the absence of recent information regarding loss of the X chromosome and ageing, we undertook a prospective study. A total of 19,650 cells from 655 females aged from birth to 80 years were screened cytogenetically. The frequency of X chromosome loss ranged from 0.07% at age <16 years to 7.3% at >65 years of age and showed a highly significant quadratic relationship between X chromosome loss and ageing (P ≤ 0.00001). We have produced a graphic representation that provides a minimum baseline age-related rate of X chromosome loss. This should assist diagnostic cytogenetics laboratories to determine the significance of 45,X cell lines detected in women of all ages. We also compared the frequency of 45,X cells in women referred with at least one spontaneous abortion with those referred for other reasons and found no significant difference. Thus, in our population, an excess of 45,X cells is not associated with pregnancy loss.

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“…5 We have recently developed a reference range for serum immunoglobulins derived from sera from 298 healthy children attending infant welfare clinics and schools in the Harrow area.5 An unexpected finding was that serum immunoglobulin concentrations in childhood are not log normally distributed, and formulas were derived to convert the raw data to normal distribution, to allow calculation of reference ranges. 5 We compare serum immunoglobulin values from 47 children presenting with febrile convulsions, with the predicted, age matched values obtained from our reference ranges.…”

Section: Discussionmentioning

confidence: 99%