Rom J Morphol Embryol 2012, 53(3):485–490 ISSN (print) 1220–0522 ISSN (on-line) 2066–8279 ORIGINAL PAPER Relationship between immunohistochemical assessment of bronchial mucosa microvascularization and clinical stage in asthma ADRIANA GRIGORAŞ 1) , IRINA-DRAGA CĂRUNTU 1) , C. C. GRIGORAŞ 2) , T. MIHĂESCU 2,3) , CORNELIA AMĂLINEI 1) 1) Histology – Department of Morphofunctional Sciences, “Grigore T. Popa” University of Medicine and Pharmacy, Iassy 2) Clinical Pneumology Hospital, Iassy 3) Pneumology – Department of Internal Medicine, “Grigore T. Popa” University of Medicine and Pharmacy, Iassy Abstract Although hardly ever used in current practice, fibrobronchoscopy may provide interesting histopathological–clinical correlations in patients diagnosed with different stages of evolutive asthma. The aim of the study was to evaluate the correlation between semi-quantitative microvascularization features and the asthma severity assessed according to the GINA classification 2006. Our study group consisted in 21 patients diagnosed with asthma of different stages of severity and two-control patients investigated by fibrobronchoscopy with associated biopsy. The tissue fragments underwent standard processing procedures for the immunohistochemical exam, using CD34 as microvascularization marker. The semi-quantitative analysis was based on the “hot spot” method and on a score system that corresponds to the microvessels density. The statistical analysis of the correspondence between CD34 score and clinical parameters was performed using the SPSS 17 software, applying non-parametric correlation tests. The CD34 evaluation showed an increase in blood vessels count in all asthmatic patients in comparison to the control group and a close correlation with the asthma severity, reflected by the FEV1 values. The statistical analysis showed an inverse correlation between FEV1 [%] values and CD34 expression (r=-0.93, p<<0.01). Our data concur to other research reports, supporting the hypothesis that angiogenesis initially facilitates the edema development and later on appears to be involved in the bronchial wall thickening, as a component of the chronic inflammatory response, with concomitant distensibility reduction. The bronchial mucosa microvascularization evaluation opens new perspectives for advanced therapies, with beneficial effects for asthmatic patients’ life quality. Keywords: CD34, microvascular density, immunohistochemistry, asthma.  Introduction The pathogenesis of asthma involves an increased responsiveness of the tracheobronchial tree to several stimuli, that otherwise would have little or no effect on healthy individuals, resulting in a chronic inflammatory disease. The fibrobronchoscopy technique has been uncovering new histopathological findings in the last 20 years since its application as a routine diagnosis tool. The fibrobronchoscopical investigation allows not only direct visualization of the large airways but also the bronchioalveolar lavage and/or the collection of tissue fragments from patients presenting at variable stages of evolutive disease [1, 2]. The chronic mucosal inflammation, accompanied by edema and a moderate increase of blood vessels density appears to be responsible for the decrease of distensibility observed in the mild asthma symptoms [3, 4]. The association between the chronic inflammation with the prominent deposition of subepithelial collagen, muscular and glandular hypertrophy and a significant increase in vessel density result in a complex remodeling pheno- menon, which is characteristic in severe asthma [5–7]. Few research reports are mainly focused on qualitative and quantitative comparative evaluation of the mucosal vascular component in asthma, and on identifying the involved stimulating factors, which are currently available in literature [8–11]. TNF-α, VEGF, and b-FGF are considered important endothelial stimulating growth factors in the bronchial wall [12]. Supplementary, VEGF is closely correlated to mucosal bronchial edema by increasing vascular permeability [10, 11]. The correlation between long- term corticosteroid therapy and bronchial vessel density has been investigated by several research teams [10, 13– 15]. The therapeutic benefits of high-dose long-term corticosteroid and of β 2 agonists’ inhalers are correlated to decreased bronchial vessel density [14, 15]. Despite the continuous research efforts, the correla- tions between vascularization and asthma pathogenesis, mainly concerning the bronchial remodeling process, remains incompletely elucidated [8, 9]. Our study is included in the current research framework, as a double histopathological and clinical approach, which has the main purpose to assess the correlation between the microvascularization semi- R J M E Romanian Journal of Morphology & Embryology http://www.rjme.ro/