mohammadreza sheikh sajjadieh

Immunofluorescence and serology analysis are the most common laboratory methods for diagnosing antinuclear antibodies in autoimmune diseases and are paramount for screening and therapeutic purposes. This study aims to estimate the sensitivity and specificity of antinuclear antibodies measured by automated indirect immunofluorescence and enzyme-linked immunoassay in patients at risk for autoimmune diseases.

Serum antinuclear antibodies in 3020 patients suspected of autoimmune diseases at Nobel Medical Laboratory, Esfahan, IRAN, were measured from 2017 until 2020 with automated indirect immunofluorescence and enzyme-linked immune assay methods. The sensitivity, specificity, prevalence, positive and negative predictive value, and likelihood ratio were calculated for each technique. In addition, the receiver operating characteristic curve (ROC) was analysed as a statistical method for assessing the diagnostic accuracy of these tests.

The immunofluorescence method demonstrated low sensitivity and high specificity compared with the enzyme-linked immunoassay. For the automated indirect immunofluorescence method, sensitivity and specificity were 88% and 62%, respectively, whereas this number for the ELISA method was determined as 89.6% and 28.5 %, respectively.

It is crucial to choose a suitable method for detecting autoantibodies for diagnostic purposes. ANA analysis by a sensitive test, such as an enzyme-linked immunoassay, should be used for screening. In contrast, a highly specific test, such as an indirect immunofluorescence assay, should be used to confirm the result and monitor dynamic treatment.

The effect of low dose radiation on immune system is shown. Ionizing radiation can affect cytokine production and polarization of T helper cells. The current study focused on ionizing radiation in Ukrainian children residing in acontaminated area with clinical irritable bowel syndrome. Our study included 75 rural children population aged 4-18 yrs, who lived in a contaminated area exposed to natural environmental radiation with clinical irritable bowel syndrome (categorized in three groups) and 20 rural children participants aged 5-15 yrs who were living in areas with similar levels of radioactive contamination without clinical irritable bowelsyndrome as control group. Internal radiation activity was measured by gamma-ray spectrometry. Serum levels of IL-4 and IFN-γ were measured by enzyme linked immunosorbent assay. A trend towards increased levels of IL-4 was observed in children with clinical irritable bowel syndrome. In these children, IFN-γ levels were lower than that of the control group. The IBS symptoms in Ukrainian children residing in a contaminated area may have stemmed from Th1 to Th2 immune deviation and differential expression of IL-4 and IFN-γ.