High concentrations of eosinophil cationic protein and eosinophil protein X in eosinophilic pleural effusions

Propylthiouracil-Associated Eosinophilic Pleural Effusion: A Case Report

We describe an unusual case of a patient with eosinophilic pleural effusion (EPE) associated with long-term propylthiouracil (PTU) administration. A 43-year-old woman was admitted to our hospital after complaining of chest pain. She had had Graves' disease, which had been treated with PTU for 11 years. Right-sided pleural effusion was detected and the result of thoracentesis confirmed an EPE. The patient's detailed medical evaluation failed to reveal any other cause of EPE. PTU was terminated since it was thought to be the cause. Despite withdrawal of the medication, however, the pleural effusion persisted for 6 weeks, and steroid therapy was planned for 15 days in decreasing dosages. During the control visit 10 days after the initiation of steroid therapy, no pleural effusion was observed, and the steroid was discontinued. Rechallenge with PTU produced recurrent pleural effusion. Therapy with PTU was again terminated, and treatment with methimazole and a brief course of low-dose corticosteroids were begun. Chest radiography revealed disappearance of the effusion within 10 days and it did not recur during a 1-year follow-up. To our knowledge, there is only 1 other case in the English-language literature describing EPE caused by PTU. Our report is of particular importance because it describes the development of that disorder in the 11th year of PTU treatment. It also shows that steroid therapy can be effective in treating drug-induced EPE.

Hypoalbuminemia as a cause of pleural effusions

BACKGROUND

Alterations in Starling forces that favor pleural fluid formation include an elevation in capillary hydrostatic pressure and a fall in plasma oncotic pressure. Although venous hypertension is a well-recognized cause of pleural effusion, the frequency with which hypoalbuminemia in the absence of volume expansion leads to pleural effusion is unclear.

STUDY OBJECTIVE

We determined the frequency with which unexplained pleural effusions occur in patients with normal and low plasma oncotic pressures.

DESIGN

A 2-month prospective screen of all admission patients to the University of Oklahoma Hospital and the Oklahoma City Veterans Administration (VA) Medical Center identified 152 patients who had chest radiographs and serum protein determinations on admission, but did not have an admission diagnosis that was a recognized cause of pleural effusion. In order to include more patients in the study with extremely low serum albumin levels, 20 additional study patients with serum albumin levels of < 2.0 g/dL were identified by a retrospective review of patients admitted during the previous 12 months. On the radiograph, pleural effusions were identified as a new blunting of the costophrenic angles. Study patients were divided into the following three groups: group 1 had serum albumin levels of > 3.5 g/dL; group 2 had serum albumin levels between 2.1 and 3.5 g/dL; and group 3 had serum albumin levels of < or = 2.0 g/dL. Finally, the frequencies with which pleural effusions occurred were compared among the three groups.

RESULTS

Seven of 104 patients in group 1, 2 of 45 patients in group 2, and 3 of 21 patients in group 3 had pleural effusions. Within each group, there were no significant differences in serum albumin concentration or plasma oncotic pressure between patients with and without pleural effusions. In all but two study patients, a careful review of records and a prospective follow-up of the patients' clinical course identified a potential cause for the effusions other than hypoalbuminemia. None of the 68 study patients with serum albumin levels of < or = 3.5 g/dL had an unexplained pleural effusion.

CONCLUSION

We conclude that hypoalbuminemia, per se, is an uncommon cause of pleural effusion. The recognition of pleural effusions in patients with low serum albumin levels should prompt careful clinical evaluations to identify other potential causes for the effusions.

Mechanisms of acute eosinophilic inflammation in a case of acute eosinophilic pneumonia in a 14-year-old girl

BACKGROUND

Acute eosinophilic pneumonia (AEP) is characterized by respiratory distress, eosinophilic infiltration in the lung, acute onset, resolution of symptoms with corticosteroids and the absence of relapse. Studies to identify the pathophysiology of AEP in adults have demonstrated eosinophil activation in the BAL fluid, and the presence of high levels of interleukin 5 (IL-5) in the BAL.

OBJECTIVE

To investigate the pathophysiology of AEP with pleural effusion in a paediatric patient.

METHODS

ECP levels in the BALand pleural fluid was determined by radioimmunoassay. IL-5 and GM-CSF concentrations in the BAL and pleural fluid were measured by Elisa. Immunohistochemistry studies performed on open lung biopsy included a specific ICAM-1 immunostaining and a ECP specific immunostaining (EG2+).

RESULTS

High levels of ECP were found in the BAL (5 microg/L) and pleural fluid (750 microg/L) demonstrating eosinophil activation at these sites. Immunohistochemistry illustrated activated (EG2+) eosinophils in the interalveolar septa and alveolar space and detected increased expression of ICAM-1 on alveolar epithelial cells. High levels of IL-5 were measured in the BAL (1334 pg/mL) and pleural fluid (7014 pg/mL), while elevated concentrations of GM-CSF (150 pg/mL) were found in the BAL.

CONCLUSION

We conclude that in this paediatric patient with AEP activated eosinophils were present in the BAL fluid, in the interalveolar septa and in the pleural space while increased ICAM-1 expression was detected on alveolar epithelial cells, contributing, at least partly, for their adhesive interactions. IL-5 and GM-CSF are likely important to the massive eosinophil recruitment and activation in the lung, while IL-5 is probably related to eosinophil accumulation and activation in the pleural space. Thus, lung generation of eosinophil-active cytokines is central to the pathophysiology of AEP in paediatric patients.