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The aim of this paper was to determine the clinical significance of the MHC class I chain-related molecule A(MICA) and NKG2D receptor on NK cells in pancreatic cancer. We compared MICA expression in malignant (n = 103), inflammatory (n = 28), and normal (n = 17) pancreatic tissues using immunohistochemistry and assessed serum levels of soluble MICA (sMICA) and NKG2D expression on NK cells in patients with pancreatic cancer (n = 103), in patients with chronic pancreatitis (n = 28), and in healthy volunteers (n = 43). Expression of MICA was detected in 89.3% of pancreatic cancer tissues, whereas fewer were expressed in inflammatory and normal pancreatic tissues. The levels of sMICA were frequently elevated in patients with advanced pancreatic cancer. The elevation of sMICA was associated with down-regulated NKG2D expression and impaired activity of NK cells. The successful tumor resection significantly decreased serum levels of sMICA and increased the NKG2D expression; there was an inverse correlation between change in sMICA levels and that in NKG2D expression. MICA expression, preoperative sMICA levels and NKG2D intensity were found to be independent prognostic factors in resected pancreatic cancer. This study supports the clinical significance of release of MICA for the malignant progression of pancreatic cancer. The successful tumor resection for pancreatic cancer may have a beneficial effect on NKG2D-mediated antitumor immunity. Our results also suggest sMICA and NKG2D expression on NK cells may be useful to identify risk patients at time point of diagnosis.

BackgroundBorder malaria, a shared phenomenon in the Greater Mekong Sub-region of Southeast Asia, is a major obstacle for regional malaria elimination. Along the China–Myanmar border, an additional problem arose as a result of the settlement of internally displaced people (IDP) in the border region. Since asymptomatic malaria significantly impacts transmission dynamics, assessment of the prevalence, dynamics and risk factors of asymptomatic malaria infections is necessary.MethodsCross-sectional surveys were carried out in 3 seasons (March and April, July and November) and 2 sites (villages and IDP camps) in 2015. A total of 1680 finger-prick blood samples were collected and used for parasite detection by microscopy and nested RT-PCR (nRT-PCR). Logistic regression models were used to explore the risk factors associated with asymptomatic malaria at individual and household levels.ResultsThe prevalence of asymptomatic Plasmodium infections was 23.3% by nRT-PCR, significantly higher than that detected by microscopy (1.5%). The proportions of Plasmodium vivax, Plasmodium falciparum and mixed-species infections were 89.6, 8.1 and 2.3%, respectively. Asymptomatic infections showed obvious seasonality with higher prevalence in the rainy season. Logistic regression analysis identified males and school children (≤ 15 years) as the high-risk populations. Vector-based interventions, including bed net and indoor residual spray, were found to have significant impacts on asymptomatic Plasmodium infections, with non-users of these measures carrying much higher risks of infection. In addition, individuals living in poorly constructed households or farther away from clinics were more prone to asymptomatic infections.ConclusionsSub-microscopic Plasmodium infections were highly prevalent in the border human populations from IDP camps and surrounding villages. Both individual- and household-level risk factors were identified, which provides useful information for identifying the high-priority populations to implement targeted malaria control.

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