Thyroid hormones which causes the thyroid to enlarge (the resulting medical condition is called "endemic colloid goitre"; see goitre). This has the effect of increasing the thyroid's ability to trap more iodide, compensating for the iodine deficiency and allowing it to produce adequate amounts of thyroid hormone. Most of the thyroid hormone circulating in the blood is bound to "transport protein"s. Only a very small fraction of the circulating hormone is free (unbound) and biologically active, hence measuring concentrations of free thyroid hormones is of great diagnostic value. When thyroid hormone is bound, it is not active, so the amount of free
Selective immunoglobulin A deficiency risk of developing autoimmune diseases in middle age. IgA deficiency and common variable immunodeficiency (CVID) feature similar B cell differentiation arrests, it does not present the same lymphocyte subpopulation abnormalities. IgA-deficient patients may progress to panhypogammaglobulinemia characteristic of CVID. Selective IgA and CVID are found in the same family. Selective IgA deficiency is inherited and has been associated with differences in chromosomes 18, 14 and 6. Selective IgA deficiency is often inherited, but has been associated with some congenital intrauterine infections. Pathogenesis of IgA Deficiency ‘In IgA-deficient patients, the common finding is a maturation defect in B cells to produce