Bronchoscopy at AAV onset helps in determining extent of lung damage

Its use found lungs to be affected in nearly all of study's 58 GPA or MPA patients

Steve Bryson, PhD avatar

by Steve Bryson, PhD |

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Nearly all ANCA-associated vasculitis (AAV) patients undergoing a bronchoscopy — a minimally invasive procedure to examine the lungs and air passages — at disease onset show lung involvement, a study reported.

Bleeding from the alveoli, the tiny air sacs in the lungs where gases are exchanged, also was the most frequent lung manifestation in these patients and the leading cause of intensive care admissions.

These findings suggest that bronchoscopy is a safe and effective way of determining the presence, type, and extent of lung damage at AAV onset.

The study, “Role of bronchoscopy for respiratory involvement in granulomatosis with polyangiitis and microscopic polyangiitis,” was published in the journal ERJ Open Research by a team of researchers at the University Hospital Center of Toulouse, France.

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Usefulness of bronchoscopy with ANCA-associated vasculitis seldom reported

AAV is a group of autoimmune diseases caused by self-reactive antibodies called anti-neutrophilic cytoplasmic autoantibodies, or ANCAs, that cause inflammation and damage to small blood vessels. The disease most commonly affects the lungs, kidneys, and the ears, nose, and throat (ENT).

Lung involvement is reported to affect up to 70% of people with microscopic polyangiitis (MPA) and up to 80% of those with granulomatosis with polyangiitis (GPA) — the two most common types of AAV.

In the lungs, damage can occur in the tiny blood vessels (capillaries) that surround alveoli, as well as the airway passages that lead to the alveoli: the trachea, the bronchi, and the bronchioles.

Respiratory symptoms in AAV patients with lung involvement can include shortness of breath, coughing up blood and/or mucus, and chest pain that worsens with deep breathing.

In these cases, bronchoscopy — a technique to examine the airways with a tiny camera at the end of a thin, flexible tube that’s inserted through the mouth or nose — may help to diagnose AAV and assess the extent of lung involvement.

But “data describing bronchoscopy findings are limited,” the researchers wrote. “In this life-threatening disease, the evaluation of the risk-benefit ratio of bronchoscopy is mandatory; the lack of data about usefulness or benefits of this examination is damaging.”

The team looked back at the medical records of 58 adults who underwent bronchoscopy when diagnosed with either MPA or GPA between 2004 and 2019. Patients’ bronchoalveolar lavage (BAL) fluid, which can be collected after washing the lungs with a saline solution during a bronchoscopy, also was examined.

Patients’ median age at diagnosis was 64.5 (range, 18-83 years), and most were men (65.5%). More than half (53.4%) had GPA, and nearly half (48.3%) were tobacco smokers.

At disease onset, all patients showed involvement of two or more organs, with the lungs being affected by AAV in nearly all cases (84.5%). Lung symptoms included shortness of breath, (63.8%), cough (53.4%), and coughing up blood (27.6%). Cough was reported significantly more often in GPA than in MPA patients.

Bleeding from the alveoli, called diffuse alveolar hemorrhage (DAH), was the most frequent lung manifestation (53.4%). This was followed by the presence of tissue nodules and masses (20.7%), trachea/bronchi involvement (10.3%), diseases marked by lung scarring (6.9%), and inflammation of the small airways in the lungs (3.4%).

DAH significantly associated with an MPA diagnosis, while nodular disease, eye and ENT manifestations, and trachea/bronchi involvement significantly linked with GPA.

Procedure detected inflammation, infections, bronchial tube abnormalities

Examination of BAL fluid from 52 patients (89.6%) found inflammation of the alveoli in 47 of them (90.4%). BAL with increasingly bloody samples was noted in 14 procedures (24.1%).

BAL confirmed a diffuse alveolar hemorrhage diagnosis in five patients (16.1%) who presented lung CT abnormalities but didn’t cough up blood or show signs of anemia (low levels of red blood cells).

BAL or bronchial samples detected lung infections in 22 patients (38% of procedures). Causes of infection included bacteria (Staphylococcus aureus, Pseudomonas aeruginosa, and Haemophilus parainfluenzae), fungi (Pneumocystis jirovecii, Aspergillus spp., and Candida spp.), and viruses (respiratory syncytial virus and influenza).

Patients with lung infections were significantly older than those without them (mean, 69.8 vs. 59.2 years). No differences in gender, prescribed therapies, or AAV type were noted in relation to infections.

Notably, bronchoscopy results led to antibiotic treatment modifications in eight of the 16 patients given antibiotics before or immediately after the procedure, highlighting its potential to help in determining the most adequate treatment for infections.

Among eight recorded deaths over nearly five years of follow-up, two were caused by bacterial infections.

Bronchoscopies showed bronchial tube abnormalities in 14 patients (24.1%) and were significantly associated with GPA and PR3-ANCAs, one of the most common types of AAV-driving antibodies.

The most common bronchial tube findings were inflammation with bleeding (50%), airway narrowing (28.6%), ulcers (14.1%), and masses of immune cells (7%).

Tissue biopsy samples examined from 17 patients (29.3%) confirmed an AAV diagnosis in six people with GPA. The “diagnosis yield of bronchial biopsies was better for visible lesions in GPA,” the team wrote.

For most patients, bronchoscopies were done under local anesthesia. Oxygen therapy was necessary for one-third of the patients during the procedure.

DAH, alone or combined with kidney failure, was the leading cause of intensive care admission (72.7%).

These findings highlight that “bronchoscopy is an informative procedure at the onset of AAV disease in patients with respiratory manifestations,” the researchers wrote.

Results also suggest that “BAL can be used to confirm DAH or diagnose superadded infection in patients scheduled for immunosuppressive therapy as induction treatment,” the team wrote, adding that “endobronchial lesions are more frequently found in GPA and should be biopsied.”