Anti-carbonic anhydrase II antibodies in end-stage renal disease patients

Carbonic Anhydrase IX as a Marker of Disease Severity in Obstructive Sleep Apnea

Background and Objectives: Carbonic anhydrase (CA) enzymes are a family of metalloenzymes that contain a zinc ion in their active sites. CA enzymes have been implied in important situations such as CO2 transport, pH regulation, and oncogenesis. CA-IX is a transmembrane glycoprotein and stimulates the expression of hypoxia-inducible factor-1 (HIF-1) CA-IX. This study aimed to determine serum CA-IX levels in OSA patients in whom intermittent hypoxia is important and to investigate the relationship between serum CA-IX levels and disease severity. Materials and Methods: The study included 88 people who applied to Malatya Turgut Özal University Training and Research Hospital Sleep Disorders Center without a history of respiratory disease, malignancy, and smoking. Patients were divided into three groups: control (AHI < 5, n = 31), mild−moderate OSA (AHI = 5−30, n = 27) and severe OSA (AHI > 30, n = 30). The analysis of the data included in the research was carried out with the SPSS (IBM Statistics 25, NY, USA). The Shapiro−Wilk Test was used to check whether the data included in the study had a normal distribution. Comparisons were made with ANOVA in multivariate groups and the t-test in bivariate groups. ANCOVA was applied to determine the effect of the CA-IX parameter for OSA by controlling the effect of independent variables. The differentiation in CA-IX and OSA groups was analyzed regardless of BMI, age, gender, and laboratory variables. ROC analysis was applied to determine the parameter cut-off point. Sensitivity, specificity, and cut-off were calculated, and the area under the curve (AUC) value was calculated. Results: Serum CA-IX levels were 126.3 ± 24.5 pg/mL in the control group, 184.6 ± 59.1 pg/mL in the mild−moderate OSA group, and 332.0 ± 39.7 pg/mL in the severe OSA group. Serum CA-IX levels were found to be higher in the severe OSA group compared to the mild−moderate OSA group and control group and higher in the mild−moderate OSA group compared to the control group (p < 0.001, p < 0.001, p < 0.001, respectively). In addition, a negative correlation between CA-IX and minimum SaO2 and mean SaO2 (r = −0.371, p = 0.004; r = −0.319, p = 0.017, respectively). A positive correlation between CA-IX and desaturation index (CT90) was found (r = 0.369, p = 0.005). A positive correlation was found between CA-IX and CRP (r = 0.340, p = 0.010). When evaluated by ROC curve analysis, the area under the curve (AUC) value was determined as 0.940 (95% CI 0.322−0.557; p < 0.001). When the cut-off value for CA-IX was taken as 254.5 pg/mL, it was found to have 96.7% sensitivity and 94.8% specificity in demonstrating severe OSA. Conclusions: Our study found that serum CA-IX value was higher in OSA patients than in control patients, and this elevation was associated with hypoxemia and inflammation. CA-IX value can be a fast, precise, and useful biomarker to predict OSA.

The Human Carbonic Anhydrase II in Platelets: An Underestimated Field of Its Activity

Carbonic anhydrases constitute a group of enzymes that catalyse reversible hydration of carbon dioxide leading to the formation of bicarbonate and proton. The platelet carbonic anhydrase II (CAII) was described for the first time in the '80s of the last century. Nevertheless, its direct role in platelet physiology and pathology still remains poorly understood. The modulation of platelet CAII action as a therapeutic approach holds promise as a novel strategy to reduce the impact of cardiovascular diseases. This short review paper summarises the current knowledge regarding the role of human CAII in regulating platelet function. The potential future directions considering this enzyme as a potential drug target and important pathophysiological chain in platelet-related disorders are described.

Detection of autoantibodies against carbonic anhydrase I and II in the plasma of patients with gastric cancer

Cancer is the second leading cause of death and gastric cancer is the fourth most common cancer type worldwide. Investigation of autoantibodies in cancer patients has been a popular research area in recent years. The aim of the current study was to investigate carbonic anhydrase I and II (CA I and II) autoantibodies in the plasma of subjects with gastric cancer based on the information and considerations of autoimmune relation of gastric cancer. Anti-CA I and II antibody levels were investigated by ELISA in plasma samples of fifty two patients with gastric cancer and thirty five healthy peers. Anti-CA I and II antibody titers of the gastric cancer group were significantly higher compared with the control group (p = 0.004, p = 0.0001, respectively). Plasma anti-CA I levels of the metastatic group were lower than the non-metastatic group and this difference was found statistically significant (p < 0.05), but there was no statistical difference between plasma anti-CA II levels of the groups. CA I and II autoantibody titers in patients with gastric cancer were found higher compared to healthy subjects and the results suggest that these autoantibodies may be involved in the pathogenesis of gastric cancer.

Autoantibodies Against Carbonic Anhydrase I and II in Patients with Acute Myeloid Leukemia

OBJECTIVE

Cancer, one of the principal causes of death, is a global social health problem. Autoantibodies developed against the organism's self-antigens are detected in the sera of subjects with cancer. In recent years carbonic anhydrase (CA) I and II autoantibodies have been shown in some autoimmune diseases and carcinomas, but the mechanisms underlying this immune response have not yet been explained. The aim of this study was to evaluate CA I and II autoantibodies in patients with acute myeloid leukemia (AML) and to provide a novel perspective regarding the autoimmune basis of the disease.

MATERIALS AND METHODS

Anti-CA I and II antibody levels were investigated using ELISA in serum samples from 30 patients with AML and 30 healthy peers.

RESULTS

Anti-CA I and II antibody titers in the AML group were significantly higher compared with the control group (p=0.0001 and 0.018, respectively). A strong positive correlation was also determined between titers of anti-CA I and II antibodies (r=0.613, p=0.0001).

CONCLUSION

Our results suggest that these autoantibodies may be involved in the pathogenesis of AML. More extensive studies are now needed to reveal the entire mechanism.