Bronchiolitis obliterans syndrome (BOS) remains the most common late-onset, noninfectious pulmonary complication after allogeneic haematopoietic stem cell transplant (HSCT) and an area of need for both prevention and treatment.
Professor Anne Bergeron, from the Hôpital Saint-Louis in Paris, told the recent ERS Congress in Paris that BOS represented 40% of the lung complications in a series of about 200 post-transplant patients.
The cumulative incidence of BOS at three years was about 11%.
Female sex was protective of BOS but a history of smoking, peripheral blood stem cells, smoking, lower respiratory tract infection or bronchial abnormalities such as thickening on lung CT scan were early risk factors for BOS.
Professor Bergeron said BOS contributed to poor outcomes especially when diagnosed early after a transplant.
While early identification held the potential to initiate treatment at an early stage in the disease process, it was unfortunately still an area of unmet need.
She said a French study of 465 patients had confirmed that azithromycin was not an effective prophylactic for BOS.
The ALLOZITHRO trial had instead been stopped early based on the negative impact of azithromycin on airflow decline and mortality.
Systemic steroids were the traditional approach to management because BOS represented pulmonary chronic graft versus host disease (cGVHD) but there was little evidence for their efficacy and numerous side effects.
“We are pulmonologists, we don’t forget supportive treatment such as bronchodilators and pulmonary rehabilitation which clearly improve the quality of the life of patients,” she told the Congress.
She added that lung transplantation had become an option for these patients.
A European study of 105 patients who had received a lung transplant for late-onset, noninfectious pulmonary complications after allogeneic HSCT found outcomes were comparable to patients receiving lung transplants for other causes.
She said there had to be a re-think on the management of BOS from diagnosis to prevention, evaluation and treatment with an urgent need for more randomised controlled trials.