Characterization of lymphocyte populations in nonspecific interstitial pneumonia*

• Main Authors: Limper Andrew H, Keogh Karina A
• Format: Article
• Language: English
• Published: BMC 2005-11-01
• Series: Respiratory Research
• Subjects: Cytokines; Lymphocytes; Nonspecific interstitial pneumonitis; Pulmonary fibrosis; Usual interstitial pneumonitis
• Online Access: http://respiratory-research.com/content/6/1/137

<p>Abstract</p> <p>Study objectives</p> <p>Nonspecific interstitial pneumonia (NSIP) has been identified as a distinct entity with a more favorable prognosis and better response to immunosuppressive therapies than usual interstitial pneumonia (UIP). However the inflammatory profile of NSIP has not been characterized.</p> <p>Design</p> <p>Using immunohistochemistry techniques on open lung biopsy specimens, the infiltrate in NSIP was characterized in terms of T and B cells, and macrophages, and the T cell population further identified as either CD4 (helper) or CD8 (suppressor-cytotoxic) T cells. The extent of Th1 and Th2 cytokine producing cells was determined and compared to specimens from patients with UIP.</p> <p>Results</p> <p>In ten NSIP tissue samples 41.4 ± 4% of mononuclear cells expressed CD3, 24.7 ± 1.8% CD4, 19.1 ± 2% CD8, 27.4 ± 3.9% CD20, and 14.3 ± 1.6% had CD68 expression. Mononuclear cells expressed INFγ 21.9 ± 1.9% of the time and IL-4 in 3.0 ± 1%. In contrast, biopsies from eight patients with UIP demonstrated substantially less cellular staining for either cytokine (INFγ; 4.6 ± 1.7% and IL-4; 0.6 ± 0.3%). Significant populations of CD20 positive B-cells were also identified.</p> <p>Conclusion</p> <p>The lymphocytic infiltrate in NSIP is characterized by an elevated CD4/CD8 T-cell ratio, and is predominantly of Th1 type, with additional populations rich in B-cells. Such features are consistent with the favorable clinical course observed in patients with NSIP compared to UIP.</p>