brace very similar cases of drug-induced pneumonitis complicating treatment of rheumatoid arthritis with low-dose methotrexate are at handed Diagnosis was suggested by clinical history and findings.
brace very similar cases of drug-induced pneumonitis complicating treatment of rheumatoid arthritis with low-dose methotrexate are at handed Diagnosis was suggested by clinical history and findings, unless the bronchoalveolar lavage showed a high percentage of neutrophils, an unusual feature in methotrexate-induced pneumonitis. Transbronchial lung biopsies (TBB) confirmed the diagnosis by way of showing interstitial lymphocytic infiltrate with microgranulomas. Although histologic findings are not strictly pathognomonic, when a differential diagnosis has to be made with infectious and rheumatoid lung disease, TBB appears to be of great promise.
(Chest 1993; 104:1620-23)
BAL = bronchoalveolar lavage; RA = rheumatoid arthritis; TBB = transbronchial lung biopsy
Weekly low-dose methotrexate sodium administration (5 to 15 mg) is used in the treatment of rheumatoid arthritis (RA) refractory to conventional antirheumatic drugs[1] The dosages used are often lower than those used in the treatment of malignancies for a like reason that severe toxic reactions are infrequently reported.[1] Methotrexate-related interstitial pneumonitis, however, has been described.[2-5] We report sum of two units cases of methotrexate-induced pneumonitis after low-dose therapy for RA in which transbronchial lung biopsy (TBB) was highly contributive to the diagnosis.
Case Reports
Case 1
This 68-year-old woman was a nonsmoker and had no history of respiratory disease. in 1967 she bring to maturityed severe RA which required treatment with salazopyrine, salicylates, and corticosteroids.
In July 1991 treatment with salicylates and corticosteroids was stopped because of slight impairment of renal function and osteoporosis. Starting forward July 15, 1991, methotrexate sodium (10 mg/wk) was administered orally with improvement of articular complaints. She received the last dose the day before her admission. From the close of September 1991, she recurrently complained of cough and febrile affection and these complaints progressively increased until admission upon October 31, 1991. She had no articular symptoms. Examination revealed an ill-appearing woman with stiff respiratory distress and fever. craving drink inspiratory crackles were heard in the two lungs. A chest radiograph (Fig 1 top) and comput tomography scan (Fig 1 bottom) showed massive interstitial infiltration of the couple lungs. Lung function tests showed a strict restrictive ventilatory impairment (Table 1) While she was breathing expanse air, the [PaO.sub.2] value was 372 mm Hg; [PaCO.sub.2], 20 mm Hg and arterial pH 750 The white offspring cell count was 4,000/[mm.sup.3], with 81 percent neutrophils, 11 percent lymphocyte 6 percent monocytes, and 2 percent basophils. The serum creatinine value was 18 mg(100 ml (normal, 05 to 12 mg(100 ml) Fiberoptic bronchoseopy was performed forward the admission day and was normal. Bronchoalveolar lavage was performed in the right middle lobe (with 3/50-ml aliquots) and the enclosed space count was 260 x [10sup3]/ml with 31 percent neutrophils, 5 percent lymphocyte and 64 percent macrophages. Stains and refinements for aerobic and anaerobic bacteria including Legionella, fungi, acid-fast organisms, virus, and Pneumocystis carinii were negative. No rise in viral or Mycoplasma titers was noted. Methotrexate was withdrawn and symptomatic treatment given. Because the clinical situation did not improve in the following 48 h TBB was performed in the right upper and lower lobes. The biopsy specimens showed an extensive lymphocytic interstitial infiltrate with granuloma formation (Fig 2) Corticotherapy was started (methylprednisolone, 2 mg/kg(d) because of persistent hypoxemia. Clinical improvement occurr after 48 h and the patient was discharged from the hospital 15 days after admission. At that time, Pao, with the patient breathing apartment air was 75 mm Hg and pulmonary infiltrates had completely disappeared forward the chest x-ray film. Pulmonary function criterions also improved (Table 1).
[TABULAR DATA OMITTED]
Cases 2
A 73-year-old woman with RA was admitted to the hospital in December 1991 with a presumptive diagnosis of pneumonia.
In 1983 she had bring to maturityed erosive symmetrical polyarthritis. Rest, physical therapy, gold salts, salicylates, penicillamine, and low-dose prednisone failed to curb her progressive arthritis.
In July 1991 oral treatment with methotrexate sodium (75 mg/wk) was initiated with progressive improvement of joint complaints. The patient was a nonsmoker and had no history of lung disease. Four weeks prior to admission, she exhibited progressively increasing breathlessness and a thirsty cough. She had taken the last dose of methotrexate onward the admission day. She was admitted with tachypnea (30 breaths by minute). She had no agitation Inspiratory crackles were heard in the pair lungs. While she received oxygen (2 L/min), the [PaO.sub.2] was 60 mm Hg; [PaCO.sub.2], 318 mm Hg; pH 753 The white children cell count was 17.500/[mm.sup.3], with 89 percent neutrophils, 3 percent lymphocyte 6 percent monocytes, and 2 percent eosinophils. The sedimentation rate was 100 mm/h
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