Characterization of lymphocyte populations in nonspecific interstitial pneumonia*

Keogh, Limper

Description

Study objectives 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. Design 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. Results 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. Conclusion 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.

Sujets

• Cytokine
• Lymphocyte
• Pulmonary fibrosis

Informations

• Publié par: biomed
• Publié le: 01 janvier 2005
• Nombre de lectures: 5
• Langue: English
• Poids de l'ouvrage: 1 Mo

Extrait

Respiratory Research

BioMedCentral

Open Access Research Characterization of lymphocyte populations in nonspecific interstitial pneumonia* Karina A Keogh and Andrew H Limper*

Address: Thoracic Diseases Research Unit, Division of Pulmonary & Critical Care Medicine, Department of Internal Medicine, Mayo Clinic College of Medicine, Rochester. MN, 55905, USA Email: Karina A Keogh  [e-mail]; Andrew H Limper*  [e-mail] * Corresponding author

Published: 15 November 2005Received: 11 March 2005 Accepted: 15 November 2005 Respiratory Research2005,6:137 doi:10.1186/1465-9921-6-137 This article is available from: http://respiratory-research.com/content/6/1/137 © 2005 Keogh and Limper; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

CytokinesLymphocytesNonspecific interstitial pneumonitisPulmonary fibrosisUsual interstitial pneumonitis

Abstract Study objectives: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. Design: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. Results: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 INFγ21.9 ± 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. Conclusion: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.

Introduction Nonspecific interstitial pneumonia (NSIP) has recently been identified as a distinct form of idiopathic interstitial pneumonia, distinguishable from usual interstitial pneu monia (UIP). NSIP has been associated with better response to immunosuppressive therapies and a more favorable prognosis [14]. Histological examination dem onstrates that NSIP is characterized by a mononuclear

lymphocytic interstitial infiltrate, with occasional foci of fibroblasts and variable collagen deposition [3,5]. How ever, the prevalence of B and T cell populations in NSIP, and specifically the CD4 or CD8 T cell content has not been fully defined in this disorder. Moreover, the relative Th1 or Th2 cytokine expression associated with this dis ease is also not yet known.

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