Usefulness of bronchoalveolar lavage in a French pediatric cohort with hypersensitivity pneumonitis

Abstract

BackgroundHypersensitivity pneumonitis (HP) is a rare interstitial lung disease in children, and very little data are available on the frequency, diagnosis, and outcomes of HP. In a pediatric cohort with HP, the characteristics of the CD4/CD8 lymphocyte ratio are often described as nonspecific.MethodsWe used the National French Database (RespiRare) to collect data from the last decade on HP. The diagnosis of HP was defined by the presence of a relevant exposure, clinical symptoms, and compatible lung imaging radiology and was usually defined by positive precipitins antibodies.ResultsA total of 16 children with a mean age of 10 years (4‐13) presented with HP. All children presented with dyspnea on exertion. Diffuse ground‐glass opacity was present in all computed tomography (CT) scans. Research guided by a questionnaire and precipitins antibodies against the corresponding antigens showed that patients were positive for contact with birds with or without fungi. Bronchoalveolar lavage (BAL) was performed in 12 children. The total cell counts were elevated in BAL fluid, with a mean value of 36% lymphocytes. The CD4/CD8 lymphocyte ratio was below one for all children.ConclusionBAL in our pediatric cohort with HP had the same characteristics as that of adults with HP. An HP diagnosis must be considered when dyspnea on exertion and diffuse ground‐glass opacity are observed. Carrying out BAL and serological tests can help diagnose and avoid lung biopsy.

Clinical Features of Hypersensitivity Pneumonitis in Children: A Single Center Study

“…BALF cell morphology, such as T-cell activation and foamy macrophages, can also be used to support the diagnosis of HP ( 30 ). The clinical utility of a reduced CD4/CD8 ratio (usually between 0.5 and 1.5 in HP) is controversial because it varies greatly and often does not decrease or even increase in chronic HP ( 31 ). To our surprise, there was no significant increase in lymphocyte counts in the BALF of 3 children who underwent bronchoscopy.…”

Pediatric hypersensitivity pneumonitis: literature update and proposal of a diagnostic algorithm

“…However, acute/inflammatory HP and chronic/fibrotic HP do not represent two distinct entities in all cases. In the French cohort [ 41 ], the most frequent clinical presentation was the subacute form. The most frequent symptoms in the French and Danish cohorts [ 7 ] were exertion dyspnea and dry cough.…”

“…Usually, before diagnosis, children are treated as asthmatic without significant clinical improvement [ 7 ]. § Environmental history: bird breeding in almost all pediatric cases [ 41 ]. ** in the presence of known exposure history to trigger typical HRCT and response to treatment, BAL is not necessary [ 29 ] …”

“…Bronchoalveolar lavage (BAL) is the most sensitive tool for detecting alveolitis in patients with suspected HP and appears to reflect the distribution of cell populations shown in biopsies [ 58 , 59 ]. BAL in children with HP usually has the same characteristics as adults with HP [ 41 ]. However, it is not always necessary, particularly among patients with a clear exposure history and typical CT findings (Table 3 ).…”

“…In addition, BAL results are nonspecific and may be seen in asymptomatic individuals with antigen exposure or individuals with nonspecific interstitial pneumonia. A marked lymphocytosis CD8+ > 20% and often > 50% of the recovered white blood cells (WBCs) is nonspecific but valuable in the case of suggestive HP [ 41 ]. A pulmonary biopsy is rarely needed and usually reserved for cases without adequate clinical criteria for HP.…”