Introduction: Autoantibodies against inflammatory cytokines may be used for the prevention of atherosclerosis. Preclinical studies consider colony-stimulating factor 2 (CSF2) as an essential cytokine with a causal relationship to atherosclerosis and cancer. We examined the serum anti-CSF2 antibody levels in patients with atherosclerosis or solid cancer.Methods: We measured the serum anti-CSF2 antibody levels via amplified luminescent proximity homogeneous assay-linked immunosorbent assay based on the recognition of recombinant glutathione S-transferase-fused CSF2 protein or a CSF2-derived peptide as the antigen.Results: The serum anti-CSF2 antibody (s-CSF2-Ab) levels were significantly higher in patients with acute ischemic stroke (AIS), acute myocardial infarction (AMI), diabetes mellitus (DM), and chronic kidney disease (CKD) compared with healthy donors (HDs). In addition, the s-CSF2-Ab levels were associated with intima-media thickness and hypertension. The analyzes of samples obtained from a Japan Public Health Center-based prospective study suggested the utility of s-CSF2-Ab as a risk factor for AIS. Furthermore, the s-CSF2-Ab levels were higher in patients with esophageal, colorectal, gastric, and lung cancer than in HDs but not in those with mammary cancer. In addition, the s-CSF2-Ab levels were associated with unfavorable postoperative prognosis in colorectal cancer (CRC). In CRC, the s-CSF2-Ab levels were more closely associated with poor prognosis in patients with p53-Ab-negative CRC despite the lack of significant association of the anti-p53 antibody (p53-Ab) levels with the overall survival.Conclusion: S-CSF2-Ab was useful for the diagnosis of atherosclerosis-related AIS, AMI, DM, and CKD and could discriminate poor prognosis, especially in p53-Ab-negative CRC.

Given that esophageal cancer is highly malignant, the discovery of novel prognostic markers is eagerly awaited. We performed serological identification of antigens by recombinant cDNA expression cloning (SEREX) and identified SKI proto‐oncogene protein and transmembrane p24 trafficking protein 5 (TMED5) as antigens recognized by serum IgG antibodies in patients with esophageal carcinoma. SKI and TMED5 proteins were expressed in Escherichia coli, purified by affinity chromatography, and used as antigens. The serum anti‐SKI antibody (s‐SKI‐Ab) and anti‐TMED5 antibody (s‐TMED5‐Ab) levels were significantly higher in 192 patients with esophageal carcinoma than in 96 healthy donors. The presence of s‐SKI‐Abs and s‐TMED5‐Abs in the patients' sera was confirmed by western blotting. Immunohistochemical staining showed that the TMED5 protein was highly expressed in the cytoplasm and nuclear compartments of the esophageal squamous cell carcinoma tissues, whereas the SKI protein was localized predominantly in the nuclei. Regarding the overall survival in 91 patients who underwent radical surgery, the s‐SKI‐Ab‐positive and s‐TMED5‐Ab‐negative statuses were significantly associated with a favorable prognosis. Additionally, the combination of s‐SKI‐Ab‐positive and s‐TMED5‐Ab‐negative cases showed an even clearer difference in overall survival as compared with that of s‐SKI‐Ab‐negative and s‐TMED5‐Ab‐positive cases. The s‐SKI‐Ab and s‐TMED5‐Ab biomarkers are useful for diagnosing esophageal carcinoma and distinguishing between favorable and poor prognoses.

Atherosclerosis is associated with vascular diseases, diabetes, and cancers. The Jumonji C-domain-containing 6 (JMJD6) gene plays an important role in diverse biological processes. In addition, autoantibodies are reportedly useful in the early diagnosis and treatment of many diseases. Here, JMJD6 was identified by serological identification of antigens by recombinant cDNA expression cloning as an antigen recognized by serum IgG from patients with unstable angina pectoris. Then, we performed amplified luminescent proximity homogeneous assay-linked immunosorbent assay using purified recombinant antigens and found elevated levels of serum anti-JMJD6 antibodies (s-JMJD6-Abs) in patients with atherosclerosis-related diseases including ischemic stroke, acute myocardial infarction (AMI), diabetes mellitus (DM), and cancers including esophageal cancer (EC), gastric cancer, lung cancer, and mammary cancer, compared with those in healthy donors. The s-JMJD6-Ab levels were closely associated with hypertension, habitual smoking, and the intima-media thickness, an atherosclerosis index. The better postoperative survival status was shown in patients with EC from the JMJD6-Ab-positive group than the negative group, especially from JMJD6-Ab-positive/PD-L1-negative group and JMJD6-Ab-positive/p53-Ab-negative group than JMJD6-Ab-negative/PD-L1-positive group and JMJD6-Ab-negative/p53-Ab-positive group, respectively. Hence, JMJD6 autoantibodies may reflect atherosclerosis severity, thereby a potential biomarker for atherosclerosis-related diseases including ischemic stroke, AMI, DM, and cancers and for predicting EC prognosis.

Aim: Atherosclerosis and diabetes mellitus (DM) often lead to severe conditions, such as acute ischemic stroke (AIS), cardiovascular disease (CVD), and chronic kidney disease (CKD). Some cancers are also associated with atherosclerosis. Therefore, identifying novel autoantibody biomarkers associated with atherosclerosis-related conditions is crucial for improving early diagnosis and risk assessment. Methods: We used an array of 9,480 proteins to detect IgG antibodies in the serum of patients with atherosclerosis. Following this screening, we quantified the antibody levels using an amplified luminescent proximity homogeneous assay-linked immunosorbent assay (AlphaLISA) with recombinant antigen proteins. Results: Ubiquitin conjugating enzyme E2 E3 (UBE2E3) was identified as a candidate antigen recognized by IgG antibodies in the sera of individuals diagnosed with atherosclerosis. Compared with healthy donors, significantly higher serum antibody levels against UBE2E3 were found in patients with AIS, DM, CVD, CKD, esophageal cancer (EC), and gastric cancer (GC), but not in those with colorectal cancer (CRC). Receiver operating characteristic (ROC) analysis revealed that the higher areas under the ROC curves for anti-UBE2E3 antibodies were observed in DM- or nephrosclerosis-associated CKD than in the others. Spearman’s correlation analysis revealed that serum anti-UBE2E3 antibody (s-UBE2E3-Ab) levels were associated with the plaque score, maximum intima-media thickness, and cardio-ankle vascular index, which are typical indices of atherosclerosis and stenosis. In the survival analysis of GC and CRC, patients who were s-UBE2E3-Ab-positive had significantly poorer prognoses than patients who were s-UBE2E3-Ab-negative. The difference became more prominent when s-UBE2E3-Abs were combined with anti-differential screening-selected gene aberrant in neuroblastoma antibody (DAN-Ab) or sclerostin domain-containing protein 1 (SOSTDC1), which are bone morphogenetic protein (BMP) antagonists. Conclusions: The s-UBE2E3-Ab marker is highly associated with atherosclerosis-related diseases, such as AIS, CVD, DM, CKD, and digestive tract cancers, suggesting the involvement of BMP signals.