Among these 178 patients, the highest eosinophil percentage in BALF was 2.6% (Table 1); in contrast, the eosinophil percentage in peripheral blood was highly variable and reached a maximum of 22.0% in one case. We categorized each subject into one of three groups (<4%, 4%–10%, and ≥10%) according to the peripheral

blood eosinophil percentage as described by Renston et al.8; we then evaluated the presence of several allergic diseases on the basis of medical records (Table 1). Although some patients with peripheral blood eosinophilia had comorbidities, such as asthma or allergic rhinitis, others did not have additional clinically apparent diseases. Percentage of peripheral blood eosinophils of <4% or ≥4% were not associated Selleck Akt inhibitor with the stage of sarcoidosis according to the results of the chi-square test. Several studies have paid special attention to eosinophil percentage in BALF in patients with sarcoidosis, and eosinophils represented over 1% of all the inflammatory Olaparib molecular weight cells only in a few cases.1, 2 and 3 Similarly, among the 178 patients examined in this retrospective study, the highest eosinophil percentage in BALF was 2.6%. To the best of our knowledge, only three sarcoidosis cases with elevated eosinophil percentage in BALF have been reported,4, 5 and 6 and in these

cases, the authors speculated the co-occurrence of chronic

eosinophilic pneumonia. In contrast, Renston et al. reported that 41% of patients with sarcoidosis showed an increase of peripheral blood eosinophil percentage more than 4%.8 In the population used in this project, peripheral blood eosinophilia, IKBKE which was defined as >4%, was observed in 35.4% patients (63/178). Some patients had comorbidities (i.e. asthma, allergic rhinitis) that would potentially cause eosinophilia. However, others did not show any evidence of comorbidities on the basis of medical records. Considering both the report by Renston et al. and the present findings, sarcoidosis might be directly associated with peripheral eosinophilia in some patients. That is, peripheral eosinophilia in patients with sarcoidosis might not always indicate coexisting allergic diseases. The mechanism underlying the co-occurrence of sarcoidosis and BALF eosinophilia is unclear. Tani et al. demonstrated that concentrations of IL-4, IL-5, and IFN-γ were increased in BALF4 in their case. Shijubo et al. discussed the possibility that factors related to migration of both CD4-positive lymphocytes and eosinophils, such as lymphocyte-chemoattractant factor (LCF) and IL-2,5 were involved. In these two previous reports, there was no description of the clinical course of concomitant sarcoidosis or BALF eosinophilia.