Th1/Th2 cell distribution in pulmonary sarcoidosis

Area of Science:

• Immunology
• Cellular Biology

Background:

• Sarcoidosis involves T lymphocyte activation and cytokine release, suggesting altered T helper cell subsets.
• The balance of T helper (Th) cell subsets (Th1, Th0, Th2) is crucial in immune responses and disease pathogenesis.

Purpose of the Study:

• To investigate Th-like cytokine patterns in different compartments of pulmonary sarcoidosis patients.
• To compare T-cell clone cytokine gene expression in peripheral blood, lung parenchyma, and bronchoalveolar lavage (BAL).

Main Methods:

• Analysis of 167 T-cell clones from peripheral blood, transbronchial biopsies (lung parenchyma), and BAL.
• Polymerase chain reaction (PCR) was used to identify cytokine gene transcripts.

Main Results:

• Peripheral blood showed a majority of T cells with intermediate cytokine profiles, with few Th1 or Th2 cells.
• Lung parenchyma exhibited a shift towards Th1 profiles, with more Th1/intermediate cells than Th2/intermediate cells.
• BAL yielded CD4+ T cells with shifts to both Th1 and Th2 profiles, and a decrease in Th0 cells.

Conclusions:

• Pulmonary sarcoidosis is characterized by an accumulation of Th1 and intermediate T cells at the site of granuloma formation.
• The alveolar lumen in sarcoidosis shows a high proportion of Th1 and Th2 cells, with a reduction in Th0 cells.