Tadashi Shinohara

Soluble Elastin Fragments in Serum Are Elevated in Acute Aortic Dissection

Objective—We aimed to establish an enzyme-linked immunosorbent assay for measuring soluble elastin fragments (sELAF) in serum and to reveal its usefulness in diagnosing acute aortic dissection (AAD). Methods and Results—An enzyme-linked immunosorbent assay to measure sELAF in serum was developed by using the newly created double monoclonal antibodies, which recognize the different epitopes of human aortic elastin. Twenty-five AAD patients, 50 patients with acute myocardial infarction (AMI), and 474 healthy individuals were enrolled in the study. The sELAF levels from healthy subjects gradually increased with aging. When the cutoff point for positivity was set at the mean+3 SD (ie, 3 SD above the mean in healthy subjects at each age), 16 AAD patients (64.0%) were found be positive, whereas only 1 AMI patient was found to be positive (2.0%). AAD patients with either an open or a partially open pseudolumen were found be 88.9% positive for sELAF, whereas those with its early closure were 0% positive. The difference in the sELAF levels between AAD patients with and without a thrombotic closure of false lumen was significant (60.3±15.6 versus 135.4±53.2 ng/mL, respectively; P <0.005). Conclusions—The sELAF level in serum may be a useful marker for helping in the diagnosis and screening of AAD and may also help to distinguish AAD from AMI.

Levels of annexin IV and V in the plasma of pregnant and postpartum women

Annexin (Anx) V is pivotal in the maintenance of pregnancy by preventing the activation of blood coagulation. The homology of the amino acid sequence between Anx IV and Anx V is highest in Anx family proteins. However, little is known about the roles of Anx IV in pregnancy. The aim of this study is to clarify the roles of circulating Anx IV and Anx V in normal pregnancy. Subjects were non-pregnant women (n = 50), 120 pregnant women, and maternal subjects just after delivery (n = 53) or postpartum (n = 67). Anx IV in the plasma of non-pregnant women was at a concentration 20 times that of Anx V. The plasma levels of Anx IV suddenly increase after delivery, but Anx V levels remain low during this period. Anx IV and Anx V exert similar levels of anticoagulant activity. Anx IV protein was expressed on the basal surface of syncytiotrophoblasts; Anx V protein, on the apical surface of syncytiotrophoblasts. These results suggest that Anx IV enters the maternal bloodstream just after delivery and might play a role in preventing disseminated intravascular coagulopathy, and that Anx V helps to prevent clotting in the placenta during pregnancy.

Quantitative analysis for soluble elastin in circulation and cell culture fluids using monoclonal antibody-based sandwich immunoassay.

Abstract We have newly established 3 distinct murine monoclonal antibodies (MoAbs) against human soluble elastin by using chemically denatured immunogen isolated from human aorta; they are designated as HASG‐2, HASG‐30, and HASG‐61‐1. All of these MoAbs were highly reactive with soluble forms of native elastin in normal human serum. HASG‐2 and HASG‐61‐1 MoAbs can recognize soluble bovine elastin as well as human antigen, but HASG‐30 cannot. The sandwich enzyme‐linked immunosorbent assay (ELISA) for human soluble elastin was developed with HASG‐61‐1 labeled with peroxidase and HASG‐30 immobilized on the microplates. The circulating levels of soluble elastin in human healthy subjects (mean±SD; 42.9±19.9 ng/mL; n=85) could be measured with full accuracy and reproducibility, and gradually increased with aging. The positive correlation between the levels and ages was statistically significant (r=0.581, p<0.0001). In addition, we could also determine the concentration of tropoelastin secreted from cultured human dermal fibroblasts accurately by this ELISA. This simple assay can be utilized for the routine clinical laboratory screening of patients with arteriosclerotic vascular diseases or to accurately determine the concentrations of tropoelastin secreted from cultured human cells.

Three-year follow-up of an atrial septal aneurysm.

This is a 3-year follow-up of a gradually ballooning atrial septal aneurysm (ASA) which developed a spontaneous echo contrast and later a mobile thrombus in the aneurysm. This clearly demonstrates one of the pathogenetic mechanisms of systemic thromboembolism associated with ASA. In view of the risk of systemic thromboembolism or the need for lifelong anticoagulation treatment, the aneurysm was excised and an atrial septal patch was fashioned to close the resultant defect.

A case of rheumatoid arthritis that developed autoimmune hepatitis associated with anti-Golgi complex antibody

Abstract A 50-year-old woman, who had been diagnosed as having rheumatoid arthritis (RA) 7 months earlier, was admitted to our hospital because of liver dysfunction. Her laboratory data and histological findings satisfied the criteria for autoimmune hepatitis (AIH) as revised by the International AIH Group. Laboratory examinations (indirect immunofluorescence and immunoblotting analyses) revealed that anti-Golgi complex antibodies (AGA) were positive in her serum. AGA are thought to be closely associated with AIH and/or liver dysfunction according to several reports.

Adsorption of anti-annexin V using dextran sulfate bound cellulose beads.

Anti‐annexin V (Anx V) antibodies are detected in SLE patients and patients with habitual fetal loss or preeclampsia. Several case reports have indicated that recurrent abortion based on antiphospholipid syndrome (APS) could be successfully treated with immunoadsorption by using dextran sulfate (DS) columns. The purpose of this study is to clarify whether or not anti‐Anx V is also adsorbed by DS‐bound cellulose beads. Sera from anti‐Anx V‐positive patients were mixed with DS‐bound cellulose beads in vitro, and the titers of anti‐Anx V were measured both before and after incubation. The anti‐Anx V titers significantly decreased after incubation. The Anx V also bound to bovine serum albumin‐conjugated DS immobilized on microtiter plates. The results of the present study lend support to the basic rationale for immunoadsorption therapy using DS columns in the treatment of habitual abortion closely associated with anti‐Anx V antibodies. J. Clin. Apheresis 15:262–265, 2000.