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Mendonça LP, Costa NDSX, do Nascimento ECT, de Oliveira MR, de Carvalho CRR, Baldi BG, Dolhnikoff M. Small airways morphological alterations associated with functional impairment in lymphangioleiomyomatosis. BMC Pulm Med 2024; 24:22. [PMID: 38195527 PMCID: PMC10777584 DOI: 10.1186/s12890-023-02837-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 12/29/2023] [Indexed: 01/11/2024] Open
Abstract
BACKGROUND Lymphangioleiomyomatosis (LAM) is a rare neoplastic and cystic pulmonary disease characterized by abnormal proliferation of the so-called LAM cells. Despite the functional obstructive pattern observed in most patients, few studies investigated the morphological changes in the small airways, most of them in patients with severe and advanced LAM undergoing lung transplantation. Understanding the morphological changes in the airways that may occur early in the disease can help us understand the pathophysiology of disease progression and understand the rationale for possible therapeutic approaches, such as the use of bronchodilators. Our study aimed to characterize the morphological alterations of the small airways in patients with LAM with different severities compared to controls, and their association with variables at the pulmonary function test and with LAM Histological Score (LHS). METHODS Thirty-nine women with LAM who had undergone open lung biopsy or lung transplantation, and nine controls were evaluated. The histological severity of the disease was assessed as LHS, based on the percentage of tissue involvement by cysts and infiltration by LAM cells. The following morphometric parameters were obtained: airway thickness, airway closure index, collagen and airway smooth muscle content, airway epithelial TGF-β expression, and infiltration of LAM cells and inflammatory cells within the small airway walls. RESULTS The age of patients with LAM was 39 ± 8 years, with FEV1 and DLCO of 62 ± 30% predicted and 62 ± 32% predicted, respectively. Patients with LAM had increased small airway closure index, collagen and smooth muscle content, and epithelial TGF-beta expression compared with controls. Patients with LAM with the more severe LHS and with greater functional severity (FEV1 ≤ 30%) presented higher thicknesses of the airways. Bronchiolar inflammation was mild; infiltration of the small airway walls by LAM cells was rare. LHS was associated with an obstructive pattern, air trapping, and reduced DLCO, whereas small airway wall thickness was associated with FEV1, FVC, and collagen content. CONCLUSION LAM is associated with small airway remodelling and partial airway closure, with structural alterations observed at different airway compartments. Functional impairment in LAM is associated with airway remodelling and, most importantly, with histological severity (LHS).
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Affiliation(s)
- Lígia Pelosi Mendonça
- Departamento de Patologia, Faculdade de Medicina, Universidade de Sao Paulo, Av. Dr. Arnaldo, 455, Cerqueira Cesar, CEP 01246-903, Sao Paulo, SP, Brasil
| | - Natalia de Souza Xavier Costa
- Departamento de Patologia, Faculdade de Medicina, Universidade de Sao Paulo, Av. Dr. Arnaldo, 455, Cerqueira Cesar, CEP 01246-903, Sao Paulo, SP, Brasil
| | - Ellen Caroline Toledo do Nascimento
- Departamento de Patologia, Faculdade de Medicina, Universidade de Sao Paulo, Av. Dr. Arnaldo, 455, Cerqueira Cesar, CEP 01246-903, Sao Paulo, SP, Brasil
| | - Martina Rodrigues de Oliveira
- Divisao de Pneumologia, Instituto do Coracao (InCor), Faculdade de Medicina, Hospital das Clinicas HCFMUSP, Universidade de Sao Paulo, Sao Paulo, SP, Brasil
| | - Carlos Roberto Ribeiro de Carvalho
- Divisao de Pneumologia, Instituto do Coracao (InCor), Faculdade de Medicina, Hospital das Clinicas HCFMUSP, Universidade de Sao Paulo, Sao Paulo, SP, Brasil
| | - Bruno Guedes Baldi
- Divisao de Pneumologia, Instituto do Coracao (InCor), Faculdade de Medicina, Hospital das Clinicas HCFMUSP, Universidade de Sao Paulo, Sao Paulo, SP, Brasil
| | - Marisa Dolhnikoff
- Departamento de Patologia, Faculdade de Medicina, Universidade de Sao Paulo, Av. Dr. Arnaldo, 455, Cerqueira Cesar, CEP 01246-903, Sao Paulo, SP, Brasil.
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