Antinuclear antibody testing in a Turkish pediatrics clinic: is it always necessary?

Introduction: the term anti-nuclear antibody (ANA) is used to define a large group of autoantibodies which specifically bind to nuclear elements. Although healthy individuals may also have ANA positivity, the measurement of ANA is generally used in the diagnosis of autoimmune disorders. However, various studies have shown that ANA testing may be overused, especially in pediatrics clinics. Our aim was to investigate the reasons for antinuclear antibody (ANA) testing in the general pediatrics and pediatric rheumatology clinics of our hospital and to determine whether ANA testing was ordered appropriately by evaluating chief complaints and the ultimate diagnoses of these cases. Methods: the medical records of pediatric patients in whom ANA testing was performed between January 2014 and June 2016 were retrospectively evaluated. Subjects were grouped according to the indication for ANA testing and ANA titers. Results: ANA tests were ordered in a total of 409 patients during the study period, with 113 positive ANA results. The ANA test was ordered mostly due to joint pain (50% of the study population). There was an increased likelihood of autoimmune rheumatic diseases (ARDs) with higher ANA titer. The positive predictive value of an ANA test was 16% for any connective tissue disease and 13% for lupus in the pediatric setting. Conclusion: in the current study, more than one-fourth of the subjects were found to have ANA positivity, while only 15% were ultimately diagnosed with ARDs. Our findings underline the importance of an increased awareness of correct indications for ANA testing

Türkiye'de seçili bölgeler için kızılötesi dalgaboylarında kara yüzeyi salıcılık değişimleri.

In this thesis, land surface emissivity variations are examined with respect to the land surface type, wavelength, and time (season and month) for the seven selected regions in Turkey using MODIS emissivity database and precipitation amount. Investigating land surface emissivity variations are important in many applications and it is known that studies about these variations are done for many regions except Turkey. This study is prior knowledge for Turkey to be used in infrared (IR) background models, surface radiation budget calculations, and land cover type classifications specific for Turkey. The results indicate that precipitation has a great influence on monthly/seasonal emissivity values depending on the land cover type and causes spectral emissivity variations. As a result, we determined appropriate IR wavelengths for the investigation of the seasonal emissivity variations and seasonal factors causing emissivity variations according to the land cover types.M.S. - Master of Scienc