Gt. Seah et al., Type 2 cytokine gene activation and its relationship to extent of disease in patients with tuberculosis, J INFEC DIS, 181(1), 2000, pp. 385-389
The extent of type 2 cytokine gene expression in patients with pulmonary tu
berculosis (TB) was studied by use of quantitative nested reverse-transcrip
tion polymerase chain reaction on freshly isolated peripheral blood mononuc
lear cells. Interleukin (IL)-4 and IL-13 mRNA expression was significantly
greater in patients-median mRNA copy numbers were 1.7 and 1.1 log(10) highe
r, respectively-than in matched tuberculin-positive control subjects. Signi
ficant correlations with radiologic extent of disease and serum IgE levels
supported the biologic significance of these results. Interferon-gamma mRNA
copy numbers exceeded those of type 2 cytokines but were only marginally l
ower in patients than in control subjects. Gene expression of an IL-4 splic
e variant (IL-4 delta 2) was bimodally distributed in both patient and cont
rol groups. Patients with greater IL-4 delta 2 expression also expressed mo
re IL-4 mRNA and had more extensive disease. Type 2 cytokines are associate
d with immunopathologic changes in TB patients but could be a cause or cons
equence of disease.