A 58-year-old patient was treated for a moderate allergic asthma since childhood. His treatment included montelukast, a moderate-dose ICS, and a long-acting β2 agonist (fluticasone-salmeterol 250/50 μg two doses per day). He also had hypertension treated with enalapril and lercanidipine. He was not a smoker and was university teacher.
His asthma was controlled without the use of oral corticosteroids (CO) until two years ago. In February 2020, symptoms of bronchitis appeared with a productive cough and exercise induced dyspnoea without spasticity. The chest X-ray was normal. His symptoms were not improved by several antibiotic cures (pristinamycin, amoxicillin and amoxicillin/clavulanic acid). Having no signs of spasticity, his general practitioner did not prescribe oral corticosteroids and he was referred to the Grenoble Alpes University hospital. He consulted in pneumology in september 2020. The clinical exam found a dyspnoea at 1 of modified Medical Research Council scale, some ronchis, no gastroesophageal reflux. PFT highlighted a moderate non-reversible obstructive ventilatory disorder with a forced expiratory volume in one second on forced vital capacity (FEV1/FCV) ratio at 50%, a FEV1 at 2.9L (72% of the theoretical) and a forced expiratory flow at 25-75% (FEF25-75) at 1.6L (48% of the theoretical). On the biological assessment, the specific anti-aspergillary immunoglobin E (IgE) was less than 0.3 kU/L (Immunocap Phadia) and the total IgE was less than 100 KU/L. Eosinophilic polynuclear blood concentration was 0.1 G/L. Blood CRP was less than 3 mg/L. Inhaled corticosteroids were therefore increased to high doses.
Two months later, the patient felt no improvement of his cough and his dyspnoea worsened. FEV1 was at 2.6L (63% of the theoretical) and a FEF25-75 at 1.3L (38% of the theoretical). At the cardiopulmonary exercise test, he reached a maximal oxygen consumption at 31,2ml/kg (90% of the theoretical). There was a respiratory limitation with an exhaustion of the ventilatory reserve (9% of the theoretical at peak effort) without desaturation. Cardiovascular adaptation was normal. A chest CT scan revealed foci of basithoracic bronchiolitis adjacent to a right 8 mm juxta-diaphragmatic nodule (figure 1A and 1B). Bronchial fibroscopy with bronchoalveolar lavage (BAL) were performed. During the fibroscopy, the macroscopic bronchial aspect was normal, the cytology of bronchial aspiration found many neutrophils without germ at the culture. The culture of BAL was positive to Nocardia abscessus at 10^4 CFU/mL.
An immunosuppression assessment was performed. The gammaglobulinemia was at 12.7 g/L, HIV serology was negative, lymphocyte immunophenotyping and fasting blood glucose were normal. Anti-GM-CSF antibodies were negative. The brain scan and skin examination were normal.
Treatment with sulfamethoxazole 800 mg + trimethoprim 160 mg two tablets three times a day was started and ICS were suspended. After three months of antibiotics, the cough and dyspnoea decreased without exacerbation of asthma. After six months of treatment, the FEV1 was 3.1L (79% of the theoretical) and the DEM was stable at 1.1L (32% of the theoretical) (Figure 2). Chest CT scan had completely normalized.