What are the causes of Bronchiolitis Obliterans (Constrictive Bronchiolitis)?

From the Guidelines

Causes of Bronchiolitis Obliterans

Bronchiolitis obliterans is a serious lung disease caused by inflammation and scarring of the bronchioles. The main causes of this condition include infections, inhalation of toxic substances, and systemic diseases such as rheumatoid arthritis and other connective tissue diseases 1. It can also occur as a complication of lung transplantation or haematopoietic stem cell transplantation (HSCT) 1.

Key Causes

• Infections: such as adenovirus or influenza
• Inhalation of toxic substances: such as sulfur mustard or nitrogen dioxide
• Systemic diseases: such as rheumatoid arthritis and other connective tissue diseases
• Lung transplantation: a common cause of bronchiolitis obliterans, occurring in over 50% of those surviving more than 5 years 1
• Haematopoietic stem cell transplantation (HSCT): a less common cause, occurring in between 2% and 14% of patients in the first 5 years post-transplant 1

Clinical Context

In the context of lung transplantation, bronchiolitis obliterans is often referred to as bronchiolitis obliterans syndrome (BOS), which is characterized by a delayed allograft dysfunction with persistent decline in forced expiratory volume in 1 s 1. The diagnosis of BOS requires careful exclusion of other post-transplant complications that can cause delayed lung allograft dysfunction 1.

From the Research

Causes of Bronchiolitis Obliterans (Constrictive Bronchiolitis)

The causes of Bronchiolitis Obliterans (Constrictive Bronchiolitis) can be categorized into several groups, including:

• Infectious causes:
  • Viral infections, such as adenovirus 2, 3
  • Mycoplasma 3
  • Lower respiratory tract infections 4
• Non-infectious causes:
  • Adverse drug reactions 5, 6
  • Toxic inhalation 6, 4
  • Autoimmune disorders, such as rheumatoid arthritis and connective tissue disease 6, 4
  • Inhalation of toxic fumes, metals, dusts, particulate matter, or pollutants 4
  • Occupational exposures 4
  • Consumption of uncooked leaves of Sauropus androgynus 4
  • Chronic hypersensitivity pneumonia 4
  • Diffuse neuroendocrine cell hyperplasia 4
• Transplant-related causes:
  • Bone marrow transplantation 6
  • Lung transplantation 6, 4
  • Heart-lung transplantation 6
  • Graft-versus-host disease (GVHD) in hematopoietic stem cell transplant (HSCT) recipients 3, 4
• Other causes:
  • Stevens-Johnson syndrome (SJS) 5
  • Cryptogenic obliterative bronchiolitis (when no cause is identified) 4