SESSION TITLE: Disorders of the Pleura
SESSION TYPE: Original Investigation Slide
PRESENTED ON: Wednesday, October 28, 2015 at 02:45 PM - 04:15 PM
PURPOSE: Valproic acid (VPA) is a branched short-chain fatty acid deriving from valeric acid, which is used in clinical practice as an anticonvulsant and moodstabilizing drug. Drugs like VPA that target chromatin through associated proteins are called epigenetic and may be applicable to a wide range of pathologies, especially cancer. Assuming that in the forthcoming years the number of patients receiving VPA will be multiplied, we try to enlighten a rather misty spectrum of its action: 2 rare toxicities that affect the respiratory system; unknown origin pleural effusion (UOPE) and pleural effusion due to drug induced lupus erythematosus (DILE).
METHODS: We studied retrospectively 129 patients receiving valproic acid for at least 1 year period. We found 2 patients with UOPE and 1 with DILE. A review of the literature revealed 13 published cases of UOPE and 9 of DILE. We compared the total 15 patients with UOPE (group A) to the 10 patients with pleural effusion due to DILE.
RESULTS: Elevated pleural and/or peripheral eosinophilia were accounted in the majority of the UOPEs than in DILE effusions (medium value serum eosinophils 11% (range 8-26) vs 8% (range 3-18); p<0.05 and medium value of pleural fluid eosinophils 19% (range 11-42) vs 11% (range 4-21); p<0.05, respectively). No other common denominator was found regarding the pleural fluid parameters - namely ph, lactate dehydrogenate, glucose, albumin - between the two groups. Accordingly, all patients with DILE were presented with positive antinuclear antibodies (ANAs) - both in serum and in pleural fluid - regardless of whether they had familiar history of systemic lupus.
CONCLUSIONS: It is suggested that the presence of eosinophilia are commonest in UOPE but ANAs is a requisite of the diagnosis of DILE while ANAs are found positive in almost all patients.
CLINICAL IMPLICATIONS: Therefore we suggest that patients should be examined for ANAs before treatment initiation with VPA. If they are found positive during their therapy but not at the onset, then the DILE should be the most obvious and probable diagnosis.
DISCLOSURE: The following authors have nothing to disclose: Dimitris Vlahopoulos, Maria Saroglou, Nikolaos Aggelis, Emmanouil Kostakis, Simos Lykogiannis, Stavros Tryfon
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