Correlation between high-resolution computed tomography findings and lung function in pulmonary Langerhans cell histiocytosis.
BACKGROUND
Pulmonary Langerhans cell histiocytosis (PLCH) is an uncommon interstitial lung disease which can lead to serious respiratory failure. The correlation between high-resolution computed tomography (HRCT) findings and lung function have not been studied in depth.


OBJECTIVE
To assess the relationship between HRCT findings and lung function in PLCH.


METHODS
Since HRCT abnormalities in PLCH consist mainly of nodular opacities and cystic abnormalities, we determined semiquantitative scores of nodular profusion and cystic extent. We therefore assessed the relationship between HRCT abnormalities on one hand and lung function and gas exchange parameters on the other, in patients with PLCH.


RESULTS
In our series of 26 consecutive patients, we found no significant correlation between the score of nodular profusion and lung function or gas exchange parameters. The score of cystic extent showed a quite strong and significant correlation with FEV(1)/FVC (r = -0.62; p = 0.01), but also with PaO(2) (r = -0.69; p = 0.001) and carbon monoxide diffusing capacity (r = -0.60; p < 0.01). Furthermore, the patients with a predominant cystic pattern (n = 7) had the highest grade of dyspnea on exertion (p = 0.004), the lowest FEV(1)/FVC ratio (p = 0.02) and the lowest PaO(2) (p = 0.02) compared to patients with a predominant nodular (n = 12) or a mixed pattern (n = 7).


CONCLUSIONS
We conclude that in PLCH, the cystic extent on HRCT, but not the nodular profusion, correlates significantly with lung function abnormalities and impairment of gas exchange.
Department of Pneumology, University Hospital, Strasbourg, France. matthieu.canuet@chru-strasbourg.fr
Matthieu
M
Canuet
Romain
R
Kessler
Mi-Young
MY
Jeung
Anne-Cécile
AC
Métivier
Ari
A
Chaouat
Emmanuel
E
Weitzenblum
D000328:Adult; D000368:Aged; D005260:Female; D006646:Histiocytosis, Langerhans-Cell / Q000175:diagnosis* / Q000503:physiopathology; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D008875:Middle Aged; D012129:Respiratory Function Tests; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed