Sub-acute occupational hypersensitivity pneumonitis due to low-level exposure to diisocyanates in a secretary

J Schreiber,J Sennekamp,J U Hahn,M Raulf-Heimsoth,K G Hering,J Knolle,R Merget,K T Schulz

doi:10.1183/09031936.00060507

Abstract

There is virtually no information in the literature about the exposure levels needed to induce hypersensitivity pneumonitis (HP) by diisocyanates. The present study reports a case of occupational HP due to diisocyanates after low-level exposure. A 53-yr-old female never-smoker developed progressive shortness of breath on exertion, cough, fatigue and flu-like symptoms shortly after she began work as a secretary of a car body repair shop. A diagnosis of HP was made 2 yrs later, based on a restrictive ventilatory defect, a reticulonodular and discrete ground-glass pattern on high-resolution computed tomography, lymphocytosis in bronchoalveolar lavage and specific immunoglobulin G antibodies to diisocyanate human serum albumin conjugates in the patient's serum. The diagnosis was confirmed by recovery after exposure cessation and deterioration after re-exposure. Ambient monitoring revealed air concentrations of different diisocyanate monomers below the detection limit in both the patient's work station and in front of the paint spray booths, with the exception of one measurement that showed 4,4-methylenediphenyl diisocyanate concentrations of 3 microg x m(-3) in front of one booth (corresponding to a total reactive isocyanate group concentration of 1 microg x m(-3)). The present authors conclude that concentrations of diisocyanates far below current exposure limits may induce hypersensitivity pneumonitis in susceptible subjects.

Highlights

A 53-yr-old female never-smoker developed progressive shortness of breath on exertion, cough, fatigue and flu-like symptoms shortly after she began work as a secretary of a car body repair shop
A diagnosis of hypersensitivity pneumonitis (HP) was made 2 yrs later, based on a restrictive ventilatory defect, a reticulonodular and discrete ground-glass pattern on high-resolution computed tomography, lymphocytosis in bronchoalveolar lavage and specific immunoglobulin G antibodies to AFFILIATIONS *Dept for Pneumonology, Otto-vonGuericke-University, Magdeburg, #Institute of Pathology, Municipal Hospital Dessau, Dessau, "Institute of Lung Diseases and Allergy, Maltesertragergesellschaft, Bonn, +BGIA, Institute for Occupational Safety and Health, German Social diisocyanate human serum albumin conjugates in the patient’s serum
Little is known about the exposure levels needed for the induction of HP by diisocyanates; one epidemiological study in a plant engineered for minimal exposure to diisocyanates did not report cases suggestive of HP [4]

Summary

Introduction

A 53-yr-old female never-smoker developed progressive shortness of breath on exertion, cough, fatigue and flu-like symptoms shortly after she began work as a secretary of a car body repair shop. CASE REPORT A 53-yr-old female, nonatopic never-smoker had (CT) scan showed discrete ill-defined centrilobular European Respiratory Journal nodules, as well as a patchy ground-glass pattern Print ISSN 0903-1936 c worked intermittently as a secretary of a car body (figs 2 and 3). In the patient’s serum, elevated specific immunoglobulin (Ig) G antibodies were found to 2,49-toluene diisocyanate (TDI; 42 mg?L-1), 4,49-methylenediphenyl diisocyanate (MDI; 62 mg?L-1), and 1,6-hexamethylene diisocyanate (HDI; 87 mg?L-1; all ImmunoCAP; Phadia, Freiburg, Germany); the cut-off for increased concentrations using this method was 20 mg?L-1.

Results

Conclusion