Abstract
Background:Vitamin D (VitD) is a key modulator of host immune response and is raised in patients with lung cancer. However, there are no studies evaluating the levels of VitD in malignant pleural effusions.
Objectives:To evaluate the diagnostic role of VitD levels in pleural effusions of various etiologies.
Methods:Prospective study of consecutive patients with a new diagnosis of pleural effusion. Exclusion criteria included previous diagnostic/therapeutic attempts or no definite diagnosis after at least 6-month follow up. Pleural fluid and serum samples were collected, protected from light exposure and immediately stored in -20°C until testing for VitD with Chemiluminescent Immunoassay.
Results:Fifty patients were studied. Pleural VitD was higher than serum VitD(p<0.001). Pleural VitD did not differ between exudates and transudates(p=0.31) but was significantly higher in malignant compared to benign effusions (p=0.037). VitD levels > 11.6 ng/ml were diagnostic for malignant effusions (Sensitivity=68%,Specificity=73%,PPV=81%,NPV=58%). Malignant effusions with positive cytology had higher levels of VitD than those with negative cytology (p=0.007). Pleural VitD did not differ between effusions caused by lung cancer versus non-lung cancer (p=0.72). VitD levels in malignant effusions above the upper quartile (i.e. 24.5 ng/ml) were related to better survival during the 6-month follow up compared to lower levels (p<0.001,log rank test).
Conclusions:Malignant pleural effusions present increased levels of VitD and higher levels of pleural VitD were associated to positive cytology, plausibly reflecting a greater local immune response. Increased levels of VitD were associated with better survival in this small population.
- © 2013 ERS