Leena Tiitto

University of Oulu, Oulu, Oulu, Finland

Are you Leena Tiitto?

Claim your profile

Publications (4)25.94 Total impact

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Fibroblastic focus (FF) is the typical histopathological feature of idiopathic pulmonary fibrosis (IPF)/usual interstitial pneumonia (UIP). A study was undertaken to analyse FF at diagnosis, to analyse the histopathological findings at necropsy, and to examine their association with the course of the disease. A retrospective study was made of 76 UIP cases collected over a period of 30 years from one university hospital; 64 had idiopathic IPF. The surface area of one slide of each lung biopsy specimen was defined by image analysis and the total number of FF was quantified. The histological features of necroscopic lung samples were re-analysed in 11 cases. Clinical follow up information was obtained from the registers. Patients with < or =50 FF/cm(2) (n = 34) in the lung biopsy specimen had a median survival of 89 months (95% CI 38 to 140) compared with 49 months (95% CI 36 to 62) in those with >50 FF/cm(2) (n = 42, p = 0.0358). Diffuse alveolar damage (DAD) was detected in 10 necropsy samples and almost prevented the histopathological confirmation of UIP in six cases. Accumulation of neutrophils occurred in nine cases. There was no association between FF at diagnosis and DAD at necropsy, or between FF and exacerbation of the disease before death. The number of FF in lung samples before death is associated with poor survival but not with DAD, which is a common feature in necropsy specimens of patients with UIP. FF cannot predict an acute exacerbation of IPF.
    Thorax 12/2006; 61(12):1091-5. · 8.38 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To evaluate the effect of lung biopsy on the survival of patients when histopathologic confirmation of usual interstitial pneumonia (UIP) is needed. Idiopathic pulmonary fibrosis is a distinct clinical entity with histopathologic features of UIP. Surgical biopsy is needed when clinical and radiologic findings are not typical. The safety of lung biopsy is a matter of debate, and the results of short-term mortality (< 30 days) after biopsy are variable. Seventy-six patients with UIP, including 34 patients who underwent video-assisted thoracoscopic surgery (VATS) biopsy and 42 patients who underwent open-lung biopsy, were included in this retrospective study. All biopsies were reevaluated for UIP histopathology. Clinical data such as age at the time of biopsy, type of biopsy, preoperative pulmonary function, major postoperative complications, date and cause of death, and survival time after the biopsy were gathered. Median survival was used to compare the survival between different groups, and cumulative survival was estimated using Kaplan-Meyer method. Thoracoscopic biopsy was safe for diagnosing UIP, with no short-term mortality. In contrast, open-lung biopsy was followed by four deaths (5.3%) within 1 month after the procedure. All fatal cases were accompanied by a histopathologic pattern of diffuse alveolar damage. Age of the patient at the time of biopsy was a significant predicting factor for survival. Patients < 50 years old lived 181 months (range, 119 to 242 months), and patients > 50 years old lived 75 months (range, 55 to 95 months). VATS biopsy is a safe procedure in diagnosing UIP.
    Chest 10/2005; 128(4):2375-80. · 7.13 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The pathogenesis of interstitial lung diseases (ILDs) is known to be associated with reactive oxygen and nitrogen metabolites and increased oxidant stress. One of the major antioxidants in human lung is glutathione (GSH) and enzymes linked to its synthesis. The rate-limiting enzyme of GSH synthesis is gamma-glutamylcysteine synthetase (gamma-GCS) containing catalytically active heavy (gamma-GCSh) and regulatory light (gamma-GCSl) subunits. It can be hypothesized that gamma-GCS is the major determinant in explaining reduced GSH levels in fibrotic lung disorders. We investigated the regulation of gamma-GCS by transforming growth factor beta(1) (TGF-beta(1)) and tumor necrosis factor alpha (TNF-alpha) in human lung cells and its expression and distribution in fibrotic (biopsy-proven idiopathic pulmonary fibrosis, for instance, usual interstitial pneumonia, UIP, n = 15), inflammatory, and granulomatous diseases of human lung parenchyma (desquamative interstitial pneumonia, n = 10; ILD associated with collagen diseases, n = 10; sarcoidosis, n = 19 and allergic alveolitis, n = 8). In human lung alveolar epithelial cells, gamma-GCSh was decreased by TGF-beta(1), whereas TNF-alpha caused a transient enzyme induction. In normal lung, gamma-GCS was mainly localized to the bronchiolar epithelium. In UIP, the highest immunoreactivities were observed in the airway epithelium and metaplastic alveolar epithelium, but fibroblastic foci were negative. In sarcoidosis, the highest reactivities were detected in the epithelium, alveolar macrophages and pulmonary granulomas. gamma-GCS was ultrastructurally localized to the cytoplasm of regenerating type II pneumocytes and macrophages. In conclusion, gamma-GCS is widely expressed in sarcoidosis and regenerating epithelium but is low in the fibrotic areas of usual interstitial pneumonia, probably because of enzyme down-regulation.
    Human Pathlogy 08/2004; 35(7):832-9. · 2.84 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The thioredoxin system containing thioredoxin (Trx) and thioredoxin reductase (TrxR) has profound effects on cell proliferation and protection against exogenous oxidants. The significance of the Trx system in human lung and lung diseases is, however, largely unresolved. Altogether, 66 specimens of human lung were investigated by immunohistochemistry for their expression of Trx and TrxR. The diseases included interstitial pneumonias such as usual interstitial pneumonia (UIP), desquamative interstitial pneumonia (DIP), and UIP associated with collagen vascular diseases (CVD-ILD), and granulomatous diseases such as sarcoidosis and allergic alveolitis. The ultrastructural localization of Trx and TrxR was analysed by immunoelectron microscopy. In healthy lung, Trx and TrxR were expressed in bronchial epithelium and alveolar macrophages. Trx and TrxR were highly concentrated in areas of metaplastic epithelium in UIP and in alveolar macrophages in DIP, though fibrotic areas in UIP were mainly negative. The expression of both enzymes was clearly weaker in CVD-ILD than in UIP. Granulomas of sarcoidosis showed moderate to intense Trx immunoreactivity. Ultrastructurally, Trx and TrxR were expressed diffusely in the cytosolic compartment and plasma membrane of metaplastic type II pneumocytes, macrophages, and bronchial epithelial cells. This study highlights the importance of Trx and TrxR in primary defence in bronchial epithelium, alveolar epithelium, and macrophages in human lung, but also indicates that elevated expression of these proteins may serve as markers of ongoing cell regeneration and inflammation.
    The Journal of Pathology 12/2003; 201(3):363-70. · 7.59 Impact Factor