久保田 真彰

Inflammation is closely associated with cerebrovascular diseases, cardiovascular diseases, diabetes, and cancers, and it is accompanied by the development of autoantibodies in the early stage of inflammation-related diseases. Hence, it is meaningful to discover novel antibody biomarkers targeting inflammation-related diseases. In this study, Jumonji C-domain-containing 6 (JMJD6) was identified by the serological identification of antigens through recombinant cDNA expression cloning. In particular, JMJD6 is an antigen recognized in serum IgG from patients with unstable angina pectoris (a cardiovascular disease). Then, the serum antibody levels were examined using an amplified luminescent proximity homogeneous assay-linked immunosorbent assay and a purified recombinant JMJD6 protein as an antigen. We observed elevated levels of serum anti-JMJD6 antibodies (s-JMJD6-Abs) in patients with inflammation-related diseases such as ischemic stroke, acute myocardial infarction (AMI), diabetes mellitus (DM), and cancers (including esophageal cancer, EC; gastric cancer; lung cancer; and mammary cancer), compared with the levels in healthy donors. The s-JMJD6-Ab levels were closely associated with some inflammation indicators, such as C-reactive protein and intima-media thickness (an atherosclerosis index). A better postoperative survival status of patients with EC was observed in the JMJD6-Ab-positive group than in the negative group. An immunohistochemical analysis showed that JMJD6 was highly expressed in the inflamed mucosa of esophageal tissues, esophageal carcinoma tissues, and atherosclerotic plaques. Hence, JMJD6 autoantibodies may reflect inflammation, thereby serving as a potential biomarker for diagnosing specific inflammation-related diseases, including stroke, AMI, DM, and cancers, and for prediction of the prognosis in patients with EC.

BACKGROUND: Autoantibodies develop in autoimmune diseases, cancer, diabetes mellitus (DM), and atherosclerosis-related diseases. However, autoantibody biomarkers have not been successfully examined for diagnosis and therapy. METHODS: Serological identification of antigens through recombinant cDNA expression cloning (SEREX) was used for primary screening of antigens. The cDNA product was expressed in bacteria and purified. Amplified luminescent proximity homogeneous assay-linked immunosorbent assay (AlphaLISA) was used to evaluate antibody levels in serum samples. RESULTS: Phosphoenolpyruvate carboxykinase 1 (PCK1) was recognized as an antigen by serum IgG antibodies in the sera of patients with atherosclerosis. AlphaLISA showed significantly higher serum antibody levels against recombinant PCK1 protein in patients with DM and cardiovascular disease than in healthy donors, but not in those with acute ischemic stroke, transient ischemic attack, or obstructive sleep apnea syndrome. The area under the receiver operating characteristic curve for anti-PCK1 antibodies was 0.7024 for DM. The serum anti-PCK1 antibody levels were associated with age, platelet count, and blood pressure. Anti-PCK1-antibody-positive patients showed significantly lower overall survival than the negative patients. CONCLUSIONS: Serum anti-PCK1 antibody levels were found to be associated with DM. The anti-PCK1 antibody marker is useful for predicting the overall survival of patients with DM.

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.

Autoantibodies can be used in the early diagnosis and treatment of atherosclerosis-related diseases. Using ProtoArray® screening of samples from patients with atherosclerosis, the present study identified thiosulfate sulfurtransferase-like domain-containing 2 (TSTD2) as a novel atherosclerosis antigen. The serum TSTD2 antibody levels were then quantified using an amplified luminescent proximity homogeneous assay-linked immunosorbent assay. This demonstrated the levels of TSTD2 antibodies (TSTD2-Abs) to be significantly higher in patients with acute cerebral infarction or chronic kidney disease than in healthy donors. The TSTD2-Ab levels were also found to be higher in males, older adults, smokers, in those who consumed alcohol regularly, and in those with hypertension. Furthermore, Spearman's rank correlation analysis revealed TSTD2-Ab levels to be strongly associated with measures of atherosclerosis severity, including plaque scores, intima-media thickness of the carotid artery and the cardio-ankle vascular index. Thus, TSTD2-Abs may thus be a promising novel biomarker for atherosclerosis-related cerebral infarction and kidney disease.

OBJECTIVE: In radiation-induced carotid artery stenosis (RIS), morphological characteristics, such as bilateral and long lesion distances and in-stent stenosis, have been reported as common after carotid artery stenting (CAS). Here, we present 25 cases at our hospital wherein CAS was performed for RIS and compare the morphological characteristics and the safety of the treatment with cases of atherosclerotic carotid artery stenosis (AS). METHODS: Twenty-five lesions from 21 patients underwent CAS for RIS at our hospital between March 2002 and July 2020. The procedure was performed at a mean of 10.0 ± 5.2 years after radiation therapy with 60-72 Gy, with a median follow-up of 45 months. We retrospectively selected consecutive patients with AS with comparable follow-up times from the beginning of the study as controls. We compared the patients' background, stenosis findings including plaque MRI, perioperative period, and postoperative course. RESULTS: All patients in both groups completed the procedure, and the median follow-up time for the RIS and AS groups was 45 and 40 months, respectively (p = 0.1479). Patients in the RIS group had a lower mean age (69.9 ± 6.9 vs. 75.3 ± 7.04, p = 0.0075), a higher stenosis rate (79.1 ± 8.7% vs. 68.6 ± 11.7%, p = 0.0032), and longer stenosis greater than one vertebra (long lesions) (10 vs. 1, p = 0.0046) compared with the patients in the AS group. Although there was no significant difference in outcomes between the two groups, restenosis tended to be more common in the RIS group. Plaque MRI was characterized by a significantly higher T2WI signal (p = 0.0381) in the RIS group, which was attributable to the fact that a necrotic core has been reported commonly in the plaque tissue of RIS. CONCLUSION: RIS has a high likelihood of restenosis both morphologically and in terms of plaque characteristics. Thus, close follow-up is crucial.

The presence of disease-specific antigens and autoantibodies in the sera of patients with atherosclerosis-related diseases has been widely reported and is considered to result from inflammation of the arterial wall and the involvement of immune factors. The aim of this study was to identify a novel antibody in patients with ischemic stroke by serological identification of antigens using recombinant cDNA expression cloning from patients who had a transient ischemic attack (TIA). We identified the serpin peptidase inhibitor, clade E member 1 (SERPINE1), as a candidate antigen. The serum anti-SERPINE1 antibody levels quantified using amplified luminescent proximity homogeneous assay-linked immunosorbent assay were significantly higher in patients with ischemic stroke, including those with acute cerebral infarction (aCI), TIA, and chronic cerebral infarction, than in healthy donors. The antibody levels were strongly associated with old age, female sex, and presence of hypertension, diabetes mellitus, and cardiovascular disease. Age and intima-media thickness of the carotid artery were positively correlated with antibody levels, which suggests that SERPINE1 may reflect the progression of atherosclerosis. In a multivariate analysis, SERPINE1 antibody level was an independent predictor of aCI. Thus, the serum levels of anti-SERPINE1 antibody could potentially serve as a biomarker of atherothrombotic infarction.

Atherosclerosis has been considered as the main cause of morbidity, mortality, and disability worldwide. The first screening for antigen markers was conducted using the serological identification of antigens by recombinant cDNA expression cloning, which has identified adaptor-related protein complex 3 subunit delta 1 (AP3D1) as an antigen recognized by serum IgG antibodies of patients with atherosclerosis. Serum antibody levels were examined using the amplified luminescent proximity homogeneous assay-linked immunosorbent assay (AlphaLISA) using a recombinant protein as an antigen. It was determined that the serum antibody levels against AP3D1 were higher in patients with acute ischemic stroke (AIS), transient ischemic attack, diabetes mellitus (DM), cardiovascular disease, chronic kidney disease (CKD), esophageal squamous cell carcinoma (ESCC), and colorectal carcinoma than those in the healthy donors. The area under the curve values of DM, nephrosclerosis type of CKD, and ESCC calculated using receiver operating characteristic curve analysis were higher than those of other diseases. Correlation analysis showed that the anti-AP3D1 antibody levels were highly associated with maximum intima-media thickness, which indicates that this marker reflected the development of atherosclerosis. The results of the Japan Public Health Center-based Prospective Study indicated that this antibody marker is deemed useful as risk factors for AIS.

BACKGROUND: Acute ischemic stroke (AIS) is a serious cause of mortality and disability. AIS is a serious cause of mortality and disability. Early diagnosis of atherosclerosis, which is the major cause of AIS, allows therapeutic intervention before the onset, leading to prevention of AIS. METHODS: Serological identification by cDNA expression cDNA libraries and the protein array method were used for the screening of antigens recognized by serum IgG antibodies in patients with atherosclerosis. Recombinant proteins or synthetic peptides derived from candidate antigens were used as antigens to compare serum IgG levels between healthy donors (HDs) and patients with atherosclerosis-related disease using the amplified luminescent proximity homogeneous assay-linked immunosorbent assay. RESULTS: The first screening using the protein array method identified death-inducer obliterator 1 (DIDO1), forkhead box J2 (FOXJ2), and cleavage and polyadenylation specificity factor (CPSF2) as the target antigens of serum IgG antibodies in patients with AIS. Then, we prepared various antigens including glutathione S-transferase-fused DIDO1 protein as well as peptides of the amino acids 297-311 of DIDO1, 426-440 of FOXJ2, and 607-621 of CPSF2 to examine serum antibody levels. Compared with HDs, a significant increase in antibody levels of the DIDO1 protein and peptide in patients with AIS, transient ischemic attack (TIA), and chronic kidney disease (CKD) but not in those with acute myocardial infarction and diabetes mellitus (DM). Serum anti-FOXJ2 antibody levels were elevated in most patients with atherosclerosis-related diseases, whereas serum anti-CPSF2 antibody levels were associated with AIS, TIA, and DM. Receiver operating characteristic curves showed that serum DIDO1 antibody levels were highly associated with CKD, and correlation analysis revealed that serum anti-FOXJ2 antibody levels were associated with hypertension. A prospective case-control study on ischemic stroke verified that the serum antibody levels of the DIDO1 protein and DIDO1, FOXJ2, and CPSF2 peptides showed significantly higher odds ratios with a risk of AIS in patients with the highest quartile than in those with the lowest quartile, indicating that these antibody markers are useful as risk factors for AIS. CONCLUSIONS: Serum antibody levels of DIDO1, FOXJ2, and CPSF2 are useful in predicting the onset of atherosclerosis-related AIS caused by kidney failure, hypertension, and DM, respectively.

OBJECTIVE: We report a case of cerebral embolism from a bacterial embolus due to infective endocarditis (IE) during treatment of bacterial meningitis. CASE PRESENTATION: During treatment of bacterial meningitis, an 82-year-old woman developed left middle cerebral artery embolism. Mechanical thrombectomy was performed, and the yellowish-white emboli were retrieved. From the culture and pathological findings of the embolus, the same bacteria as the meningitis, Streptococcus gordonii, was identified and was considered to originate from IE. She was treated by postoperative antibiotics, but was transferred to the rehabilitation hospital on the 37th postoperative day due to slight right hemiparesis. CONCLUSION: We should always consider bacterial embolism in acute ischemic stroke combined with bacterial meningitis.

The reported growth rate of vestibular schwannoma varied widely in the literature. However, emergence of vestibular schwannoma remains unsolved. We presented three patients who had undergone previous magnetic resonance imaging (MRI) confirming the absence of tumor and were diagnosed with a unilateral vestibular schwannoma with a diameter of 18-30 mm, 6-9 years after the initial MRI. One patient had solid tumor and experienced stereotactic radiosurgery. Following stereotactic radiosurgery, continuous tumor growth led to hydrocephalus and trigeminal dysfunction, resolved by surgical removal. Other two patients had the tumor with cystic component and experienced surgical removal as first treatment. All tumors were pathologically diagnosed as schwannomas without evidence of high potential of proliferation. This is the first report of three patients with de novo vestibular schwannoma, showing tumor emergence and rapid growth in a short period. Considering a de novo aspect, the "wait and scan" policy may not be appropriate for the subset of VS such as de novo VS.

PURPOSE: To determine whether thrombolysis with a lower dose of intravenous recombinant tissue plasminogen activator before mechanical thrombectomy is beneficial for functional outcomes compared with mechanical thrombectomy alone. MATERIALS AND METHODS: Data for 100 Japanese patients who underwent mechanical thrombectomy between July 2014 and November 2017 were retrospectively reviewed. These patients were divided into groups according to whether they received intravenous thrombolysis before mechanical thrombectomy, and outcomes were compared. Favorable outcome was defined as a modified Rankin scale score ≤ 2 at 3 months after treatment. RESULTS: Thirty-four patients for the thrombolysis group and 66 patients for the thrombectomy-only group were identified. The thrombolysis and nonthrombolysis groups did not differ significantly in baseline characteristics (mean age, 74.3 y vs 75.7 y [P = .485]; mean preoperative National Institute Health Stroke Scale score, 19.8 vs 19.6 [P = .825]). There were no significant differences in the times required for, or the rates of, successful recanalization. However, the thrombolysis group had a higher rate of complete recanalization (67.6% vs 43.9%; P = .041). Postoperative symptomatic intracranial hemorrhage was not significantly different between groups. Favorable outcomes were observed in 73.5% of patients in the thrombolysis group and 51.5% in the nonthrombolysis group (P = .028). CONCLUSIONS: This single-center retrospective study shows that lower-dose intravenous thrombolysis improves the outcomes of mechanical thrombectomy for Japanese patients with acute anterior-circulation stroke treated within 4.5 hours of onset.

Untreated infective endocarditis (IE) often produces infective emboli in major cerebral arteries. We describe a case of middle cerebral artery occlusion due to IE, which caused severe vasospasm and reocclusion after mechanical thrombectomy (MT). We present the pathologic findings of the occluded middle cerebral artery and investigate the precautions to be taken while performing MT due to IE. A 72-year-old man with atrial fibrillation treated with dabigatran presented with right hemiparesis and aphasia. A diffusion-weighted image showed a high-intensity area in the left temporoparietal junction, and magnetic resonance angiography revealed a left M2 occlusion. Because of an elevated activated partial thromboplastin time, the thrombolytic therapy was contraindicated; instead, MT was performed. Just after the withdrawal of a stent retriever, the left M2 segment showed severe vasospasm. The next day, the left M2 segment reoccluded. Transthoracic echocardiogram and blood culture findings revealed IE. On the ninth day, the patient died. According to the autopsy report, the cause of death was pulmonary embolism. Pathologic analysis of the occluded M2 segment revealed fibrin thrombi containing vast amounts of neutrophils and invasion of neutrophils into the internal elastic lamina. Severe vasospasm was thought to have occurred because the vascular injury caused by the stent retriever in the vessel had a marked inflammation background. Our findings suggest that devices that are less invasive to the vascular wall are required for performing MT due to IE. The Penumbra aspiration system is thought to be a suitable device.