Serum levels of KL-6 are useful biomarkers for severe radiation pneumonitis

Evaluation of serum KL-6 as a predictive marker of radiation pneumonitis in patients with breast-conservation therapy

“…On the other hand, in our study, no patients suffered from the severe radiation pneumonitis reported by Goto et al 10 (2) In breast-conserving surgery, the numbers of cancer cells are too low to elevate KL-6 serum levels significantly, even though cancer cells are present in the mammary gland. KL-6 serves as a tumor marker for cancer of the lung, pancreas, and breast, 4,16 and KL-6 serum levels naturally rise in conditions of preoperative irradiation, recurrence, or metastasis.…”

“…The radiation pneumonitis observed in four of our patients was localized pneumonitis; the pneumonitis did not spread invasively to surrounding tissue or to the other lung. Goto et al 10 performed radiotherapy in patients with lung cancer and reported that, in patients with severe radiation pneumonitis, KL-6 serum levels increased to levels 1.5 times higher than the pre-radiotherapy levels.…”

“…6,7 The threshold for the KL-6 level for the clinical diagnosis of interstitial pneumonia is generally set at around 465 U/ml. 8 Kohno et al 9 reported that serum KL-6 was a better marker for radiation pneumonitis than other serum markers, and Goto et al 10 reported that measurements of serum KL-6 levels were useful in the early diagnosis of radiation pneumonitis in lung-cancer patients.…”

Serum biomarkers in idiopathic pulmonary fibrosis

“…Upon epithelial breakdown, KL-6 is thought to leak into the circulation, where it can be measured by a commercially available ELISA kit. KL-6 has been studied extensively in mainly Japanese patients, where serum levels were found to be increased in various interstitial lung diseases such as radiation pneumonitis [22][23][24], CTD-associated lung disease [25][26][27] and drug induced pneumonitis [28]. Interestingly, KL-6 may have a role in fibrosis itself, as it was shown to induce proliferation of lung fibroblasts in vitro [29].…”

KL-6 and Surfactant Proteins A and D in Serum and Bronchoalveolar Lavage Fluid in Patients with Acute Eosinophilic Pneumonia

“…This epitope is detected mainly in alveolar typeII cells and bronchiolar epithelial cells (3)(4)(5). The serum levels of KL-6 are elevated in patients with idiopathic pulmonary fibrosis (IPF), radiation pneumonitis, active hypersensitivity pneumonitis, pulmonary sarcoidosis, pneumocystis carinii pneumonia, and advanced pulmonary tuberculosis (5)(6)(7)(8). The serum levels of KL-6 are not elevated in patients with bacterial pneumonia or emphysema.…”