ABSTRACT
SUMMARY OBJECTIVE: This study aimed to evaluate the SARS-CoV-2 immunoglobulin G (IgG) levels after 6 months of polymerase chain reaction (PCR) negative but assumed to be COVID-19 positive cases to investigate the relationship between IgG levels and thoracic computed tomography (CT) findings. METHODS: This was a single-center study that included patients whose PCR test results were negative at least three times using nasopharyngeal swabs but had clinical findings of COVID-19 and thoracic CT findings compatible with viral pneumonia. Six months after discharge, the IgG antibodies were analyzed. The cutoff value for negative and positive serology was defined as <1.4 (index S/C) and ≥1.4 (index S/C), respectively. In addition, the patients were categorized according to their thoracic CT findings as high (typical) and low (atypical). Also, the patients were grouped into classes as <5% lung involvement versus ≥5% lung involvement. RESULTS: The patients' mean age was 49.78±12.96 years. PCR was negative, but patients with COVID-19 symptoms who had SARS-CoV-2 IgG positive were 81.9% (n=95). The antibody titer and lung involvement ≥5% were statistically significantly higher in SARS-CoV-2 IgG positive cases (p<0.001 and p=0.021). Age and chest CT findings were the risk factors for lung involvement (OR=1.08, p<0.001 and OR=2.19, p=0.010, respectively). CONCLUSION: This study is valuable because increasing severity (≥5%) of lung involvement appears to be associated with high and persistent IgG antibody titers. In probable cases of COVID-19, even if the PCR test is negative, high IgG titers 6 months after discharge can predict the rate of lung parenchymal involvement.
ABSTRACT
SUMMARY OBJECTIVE: Many chronic diseases such as malignancy, cardiovascular diseases, endothelial dysfunction, and autoimmune diseases, which have been shown to be related to vitamin D in various studies; have similar relations with CTRP-9, TNFα, and thiol-disulfide hemostasis. We aimed to contribute to the literature by evaluating the relationship between CTRP-9, TNFα, and thiol-disulfide hemostasis and vitamin D levels, which we thought may have some effects on the pathogenesis of vitamin D deficiency. METHODS: In our study, 78 female volunteers older than 18 years were included. Volunteers were divided into three groups according to the reference values of vitamin D levels. Biochemical parameters, CTRP-9, TNFα, and thiol/disulfide hemostasis tests taken from all volunteers were studied. RESULTS: In this study, there was a significant difference in CTRP-9, TNFα, total thiol (TT), native thiol (NT), DIS (disulfide), TT/DIS, and NT/DIS levels in vitamin D groups (p<0.05). There was a significant negative correlation between vitamin D and TNFα and DIS, while a significant positive correlation was found with CTRP-9, TT, NT, TT/DIS, and NT/DIS (p<0.05). CONCLUSIONS: It was determined that vitamin D deficiency causes a significant decrease in CTRP-9 level and a significant increase in TNFα level, as well as an increase in thiol/disulfide hemostasis in favor of disulfide, which may be a risk factor for increased oxidative stress. We considered that these changes may play mediator roles for many chronic diseases and metabolic disorders that are increasing in frequency due to vitamin D deficiency.