INTRODUCTION: Pulmonary Langerhans cell histiocytosis (PLCH) or eosinophilic granuloma of the lung is an uncommon interstitial lung disease that affects primarily young adults. No occupational or geographic predisposition reported, but nearly all affected individuals have a history of current or prior cigarette smoking. We recently had a patient with PLCH developed after one and half year of diagnosis of multiple sclerosis (MS). To the best of our knowledge, no case of PLCH has been reported in a patient with MS.
CASE PRESENTATION: A 27-year-old female patient known to have multiple sclerosis presented to our ER with cough and shortness of breath of one month's duration. Patient started having progressively worsening exertional dyspnea with limitation of activity as well as dry cough. There was no history of hemoptysis, weight loss, orthopnea, wheezing, paroxysmal nocturnal dyspnea or recurrent sinusitis. No change in living conditions or night sweats. Pt did not receive any new medication. There was ten-pack year history of cigarette smoking. Patient was on gabapentin and baclofen before her presentation to ER. There was no significant family history of heart, lung or neurological disease. Vital signs on admission were stable and she was in no distress. Cardiovascular examination was normal while lung exam was significant for slightly prolong expiratory phase and bilateral crackles. A chest radiograph showed asymmetric densities with increased markings in the left hemi-thorax. Chest CT revealed multiple bilateral and predominantly upper lobe thin walled air-filled cysts. A specimen obtained at lung biopsy confirmed the diagnosis of Langerhans cell histiocytosis characterized by atypical histiocytoid cells with grooved nuclei. Immunostaining pattern was positive with S100 and CD1a. Skeletal survey was negative for bony disease. She was instructed to stop smoking and schedule for chemotherapy. Patient received four cycles of vinblastine and prednisone. Following the treatment with vinblastine, repeat CT of chest shown substantial improvement with vast majority of previously noted cystic and nodular changes resolved.
DISCUSSIONS: Both Multiple Sclerosis and PLCH are common in young adults. The most widely accepted theory is that MS is an inflammatory autoimmune disorder mediated by autoreactive T-cells directed against components of myelin.  There have been some reports about possible involvement of immune complexes in a pathogenesis of PLCH.  PLCH also has several abnormalities in immune function as manifested by increase in IgG in bronchoalveolar lavage, circulating immune complexes and abnormal T-cell function. PLCH also reported with other autoimmune disease like celiac disease but no link was suggested with this entity.
CONCLUSION: Apart from habitual smoking as a risk factor, PLCH may be part of wide variety of autoimmune disease spectrum. In our case one question is still unanswered that is it just coincidence that MS and PLCH present in our patient or it is immune function dysregulation causing both condition.
DISCLOSURE: Eric Costanzo, No Financial Disclosure Information; No Product/Research Disclosure Information