Eosinophilic pleural effusions

Our plain-English summary of Eosinophilic pleural effusions, by I. Kalomenidis, R.W. Light (Current Opinion in Pulmonary Medicine, 2003).

The study

• Authors: I. Kalomenidis, R.W. Light
• Journal: Current Opinion in Pulmonary Medicine
• Published: 2003;9(4):254-60
• Type of article: Review
• Cited by: 71 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Eosinophilic pleural effusions, defined as a pleural effusion that contains at least 10% eosinophils, may be caused by almost every condition that can cause pleural disease. Eosinophilic pleural effusion occurs most commonly during conditions associated with the presence of blood or air in the pleural space, infections, and malignancy. Drug-induced pleural effusions, pleural effusions accompanying pulmonary embolism, and benign asbestos pleural effusions are also among the common causes of eosinophilic pleural effusion. No etiology is found in as many as one third of patients. Because studies evaluating different diagnostic approaches with eosinophilic pleural effusions are lacking, the authors suggest that certain noninvasive and invasive diagnostic tools must be used based on the patient's clinical characteristics.

In plain English

This article was a narrative review, not a new study. The authors summarized published case reports and series on eosinophilic pleural effusion, defined as fluid around the lung containing at least 10% eosinophils (a type of white blood cell). They added some figures from their own hospital. Benign asbestos pleural effusion was listed among the common causes, and malignant mesothelioma was also listed as a cause. Citing earlier studies, the authors wrote that benign effusions in people exposed to asbestos appear a mean of 30 years (range 1 to 58 years) after first exposure, and that 25 to 50% of these effusions are eosinophilic. One earlier review had attributed 4% of eosinophilic effusions to benign asbestos effusion. At the authors' hospital, 15 of 172 eosinophilic effusions (8.7%) found since 1997 were malignant. The authors noted that some authors had speculated that some unexplained cases are benign asbestos effusions. They concluded that the patient's history should cover asbestos exposure. They also concluded that testing should be chosen according to each patient's clinical characteristics, because studies comparing diagnostic approaches are lacking.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: narrative review of published case reports and clinical series, with some data from the authors' own hospital
• Who was studied: Published cases of eosinophilic pleural effusion, including 343 cases from the English-language literature up to 1983 summarized by Adelman et al. and four later studies with 146 patients, plus 172 eosinophilic effusion cases at the authors' hospital since 1997
• Exposure: Not an exposure study. Asbestos exposure was discussed as one cause of eosinophilic pleural effusion, through benign asbestos pleural effusion. No fiber types were named.
• Main results:
  • Citing earlier studies, eosinophilic effusions account for 5 to 16% of exudative pleural effusions
  • Citing earlier studies, 25 to 50% of benign asbestos pleural effusions are eosinophilic
  • In the earlier review by Adelman et al., 4% of eosinophilic effusions were benign asbestos pleural effusions
  • Citing earlier studies, benign asbestos pleural effusions lasted a median of 3 months (range 1 to 10 months) and recurred often. Long-term prognosis was good, although some patients developed pleural fibrosis.
  • Malignant mesothelioma was listed in the authors' table of causes of eosinophilic pleural effusion
  • At the authors' hospital, 15 of 172 eosinophilic effusion cases (8.7%) found since 1997 were malignant
  • Pooling three earlier studies, after excluding obviously benign effusions, malignancy was the cause in 25 of 79 eosinophilic effusions (31.6%) and 282 of 660 non-eosinophilic effusions (42.7%)
  • Some earlier authors speculated that a proportion of patients with unexplained (idiopathic) eosinophilic effusion have benign asbestos pleural effusion
• The authors' conclusion: The authors suggested that the clinical history should include asbestos exposure, and that noninvasive and invasive diagnostic tools should be chosen based on the patient's clinical characteristics
• Limitations the authors state:
  • Most information comes from small series and case reports
  • Some cases may have been wrongly attributed to other causes when they actually resulted from thoracentesis (draining the fluid with a needle). The extent of this is unknown.
  • Studies evaluating different diagnostic approaches are lacking
  • The role of chest CT in diagnosis has not been evaluated

Topics

The National Library of Medicine indexes this study under subjects our site covers: Pleural plaques and thickening.

Medical terms in this study, explained in our Lexicon: Eosinophilic, Pleural Effusion, Benign Asbestos Pleural Effusion, Etiology.

Related studies

• Pathogenesis of the eosinophilic pleural effusions — I. Kalomenidis, R.W. Light (2004)
• Effectiveness of Nivolumab on Sarcomatoid Malignant Pleural Mesothelioma With Eosinophilia and Eosinophilic Pleural Effusion — M. Yamazoe, H. Ozasa, et al. (2019)
• Occupational Exposures and Smoking in Eosinophilic Granulomatosis With Polyangiitis: A Case-Control Study — F. Maritati, F. Peyronel, et al. (2021)
• Diagnostic utility of pleural fluid eosinophilia — M. Adelman, S.M. Albelda, et al. (1984)
• Interleukin-5-producing malignant pleural mesothelioma with eosinophilic pleural effusion — E. Takeuchi, N. Takahashi, et al. (2020)
• Eosinophil colony-stimulating factor induced by administration of interleukin-2 into the pleural cavity of patients with malignant pleurisy — Y. Nakamura, T. Ozaki, et al. (1990)

Browse more research in Current Opinion in Pulmonary Medicine, or return to medical research.