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Introduction: Kawasaki disease (KD) is the leading cause of acquired heart abnormalities during childhood. The infiltration of CD8+ T cells plays an essential role in the formation of coronary aneurysms. Follicular cytotoxic T (Tfc) cells are a newly defined subset of CD8+ T cells that express CXC-chemokine receptor 5. The role of Tfc cells in KD is unclear. However, in this report, we present 2 KD children with sustained coronary artery aneurysms (CAA), and we found that their peripheral C-X-C Chemokine Receptor 5+ T cells contained quite amounts of CD4 negative cells. Importantly, these cells have never been reported in KD., Patients Concerns: Case 1 was a 3-year-old boy with a complaint of continuous fever for 6 days and conjunctival injection for 3 days. Case 2 was a 6-month-old boy who was hospitalized because of persistent fever for 5 days, rashes and conjunctival injection for 1 day., Diagnosis: Case 1 was diagnosed with KD according to typical symptoms and signs including fever over 5 days, conjunctival injection, rashes, swelling cervical lymph nodes and a strawberry tongue. Case 2 had atypical symptoms including persistent fever for 5 days, rashes and conjunctival injection, and he was diagnosed with KD based on the echocardiographic findings., Intervention: Both the 2 patients received intravenous immunoglobulin and oral aspirin. Besides, case 1 was given the second infusion of intravenous immunoglobulin, intravenous prednisolone and low-molecular-weight heparin., Outcomes: The CAA of case 1 did not regress until the 12th month after disease onset. The CAA of patient 2 began to regress at the third month after disease onset. During the months from disease onset to the recent follow-up, no cardiovascular events had occurred., Conclusions: We speculate that Tfc cells may be associated with the formation of CAA. Further studies with larger sample size and functional analysis of these cells are needed., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2020 the Author(s). Published by Wolters Kluwer Health, Inc.)

Objective: Kawasaki disease (KD) is an acute vasculitis of childhood, predominantly affecting the coronary arteries. S100A12, a granulocyte-derived agonist of both the receptor for advanced glycation end products (RAGE) and Toll-like receptor 4 (TLR-4), is strongly up-regulated in KD. This study was undertaken to investigate the potential contributions of S100A12 to the pathogenesis of KD., Methods: Serum samples from patients with KD (n = 30) at different stages pre- and post-intravenous immunoglobulin (IVIG) treatment were analyzed for the expression of S100A12, cytokines, chemokines, and soluble markers of endothelial cell activation. Primary human coronary artery endothelial cells (HCAECs) were analyzed for responsiveness to direct stimulation with S100A12 or lipopolysaccharide (LPS), as assessed by real-time quantitative reverse transcription-polymerase chain reaction analysis of cytokine and endothelial cell adhesion molecule messenger RNA expression. Alternatively, HCAECs were cultured in conditioned medium obtained from primary human monocytes that were stimulated with LPS or S100A12 in the absence or presence of IVIG or cytokine antagonists., Results: In the serum of patients with KD, pretreatment S100A12 levels were associated with soluble vascular cell adhesion molecule 1 titers in the course of IVIG therapy (r s = -0.6, P = 0.0003). Yet, HCAECs were not responsive to direct S100A12 stimulation, despite the presence of appropriate receptors (RAGE, TLR-4). HCAECs did, however, respond to supernatants obtained from S100A12-stimulated primary human monocytes, as evidenced by the gene expression of inflammatory cytokines and adhesion molecules. This response was strictly dependent on interleukin-1β (IL-1β) signaling (P < 0.001)., Conclusion: In its role as a highly expressed mediator of sterile inflammation in KD, S100A12 appears to activate HCAECs in an IL-1β-dependent manner. These data provide new mechanistic insights into the contributions of S100A12 and IL-1β to disease pathogenesis, and may therefore support current IL-1-targeting studies in the treatment of patients with KD., (© 2018, American College of Rheumatology.)

Coronary artery ectasia describes a local or diffuse dilatation of the epicardial coronary arteries. This review summarizes the molecular and cellular mechanisms involved in the pathogenesis of coronary artery ectasia. Better identification of the pathophysiologic steps will shed light into the clinical significance and may have direct implications for the management strategies of this disease. Additionally, understanding the underlying etiology may help to improve treatment modalities specific to coronary artery ectasia., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Kawasaki disease (KD) is an acquired cardiac disease with a high incidence that affects children. KD has various complications, including coronary artery dilation (CAD) and coronary artery aneurysms (CAA). The identification of differentially expressed proteins and the underlying mechanisms may be the key to understanding differences between these KD complications. In the present study, isobaric tags for relative and absolute quantitation were used to identify variations in serum proteins between KD patients with CAD and CAA. In total, 87 (37 upregulated and 50 downregulated) and 65 (33 upregulated and 32 downregulated) significantly differentially‑expressed proteins were identified in comparisons between control samples (healthy individuals) and those obtained from patients with KD and with CAD or CAA. Investigation into the underlying biological process revealed that variations between the two complications were associated with the wound healing response, as well as lipoprotein‑ and cholesterol‑associated processes. Important proteins involved in the formation of the wound healing signaling network were identified via enriched biological processes and pathway analysis using ClueGo and ReactomeFIViz software. In the present study, 5 significantly differentially‑expressed proteins, including mannose binding lectin 2 (MBL2), complement factor H (CFH), kininogen 1 (KNG1), serpin family C member 1 (SERPINC1) and fibronectin 1 (FN1), were selected and confirmed by western blotting. Analysis indicated that these proteins were associated to immunity, inflammation and metabolism, serving a key role within each module, which has never been reported previously. The present study proposed that MBL2, CFH, KNG1, SERPINC1 and FN1 may be a potentially excellent indicator group for distinguishing the two major KD complications, CAD and CAA.

Background: Transcatheter closure of congenital coronary artery fistulas (CCAFs) is an alternative therapy to surgery; however, data regarding transcatheter closure for CCAF with a giant coronary artery aneurysm (CAA) in pediatric patients are still limited due to the rarity of the disease. We aimed to evaluate the efficacy and safety of transcatheter closure for CCAF with a giant CAA in a pediatric population at a single center., Methods: Medical records of pediatric patients (<18 years old) who underwent transcatheter closure of CCAF with a giant CAA between April 2007 and September 2016 at Guangdong Cardiovascular Institute (Guangdong, China) were reviewed., Results: Twelve patients (median age, 6.1 years; range, 1.9-11.0 years) underwent successful transcatheter closure procedures. One patient underwent closure at both the entry and exit points of the CAA, three patients underwent closure at the exit point of the CAA, and eight patients underwent closure at the entry point of the CAA. After a mean follow-up of 7.2 years (range, 0.5-9.8 years), one patient (with closure at the exit point of the CAA) underwent transcatheter re-intervention because of a significant residual shunt. She eventually underwent a surgical procedure due to aneurysm dilation after the second intervention. One patient experienced thrombus formation within the CAA after the procedure. Among those with closure at the entry point of the CAA, a mild-to-moderate residual shunt was detected in three patients., Conclusions: Transcatheter closure appears to be a safe and effective alternative therapy for CCAF with a giant CAA in the pediatric population. Closure at the entry point of the CAA, and closure at both the entry and exit points when feasible, may reduce the risk of postinterventional complications.

Background: Kawasaki disease (KD) is an acute pediatric vasculitis in which host genetics influence both susceptibility to KD and the formation of coronary artery aneurysms. Variants discovered by genome-wide association studies and linkage studies only partially explain the influence of genetics on KD susceptibility., Methods and Results: To search for additional functional genetic variation, we performed pathway and gene stability analysis on a genome-wide association study data set. Pathway analysis using European genome-wide association study data identified 100 significantly associated pathways (P<5×10 - 4 ). Gene stability selection identified 116 single nucleotide polymorphisms in 26 genes that were responsible for driving the pathway associations, and gene ontology analysis demonstrated enrichment for calcium transport (P=1.05×10 - 4 ). Three single nucleotide polymorphisms in solute carrier family 8, member 1 (SLC8A1), a sodium/calcium exchanger encoding NCX1, were validated in an independent Japanese genome-wide association study data set (meta-analysis P=0.0001). Patients homozygous for the A (risk) allele of rs13017968 had higher rates of coronary artery abnormalities (P=0.029). NCX1, the protein encoded by SLC8A1, was expressed in spindle-shaped and inflammatory cells in the aneurysm wall. Increased intracellular calcium mobilization was observed in B cell lines from healthy controls carrying the risk allele., Conclusions: Pathway-based association analysis followed by gene stability selection proved to be a valuable tool for identifying risk alleles in a rare disease with complex genetics. The role of SLC8A1 polymorphisms in altering calcium flux in cells that mediate coronary artery damage in KD suggests that this pathway may be a therapeutic target and supports the study of calcineurin inhibitors in acute KD., (© 2016 American Heart Association, Inc.)

Purpose. Kawasaki disease (KD) is a systemic vasculitis and is a leading cause of coronary artery lesions (CALs) in childhood. Our previous study has shown higher levels of serum Resistin in KD patients with coronary aneurysm. This study aimed at examining the association of Resistin with inflammatory cytokine expression in mouse model of coronary arteritis and determining the potential mechanisms. Methods. C57BL/6 mice were injected with Lactobacillus cell wall extract (LCWE) to induce coronary arteritis. The relative levels of Resistin, TNF- α , IL-1 β , and MMP-9 expression and inflammatory infiltrates in the coronary arteries were determined longitudinally by quantitative RT-PCR, ELISA, and histology. The effect of TLR4 and NF- κ B activation on Resistin-induced TNF- α and IL-1 β expression in human coronary artery endothelium cells (HCAECs) was examined by quantitative RT-PCR. Results. Higher levels of Resistin, TNF- α , IL-1 β , and MMP-9 expression were associated with the degrees of inflammatory infiltrates in the coronary artery walls of the LCWE-injected mice. Resistin enhanced TNF- α and IL-1 β expression in HCAECs at 18 or 24 hours after stimulation. Pretreatment with anti-TLR4 attenuated Resistin-enhanced IL-1 β , but not TNF- α , expression and pretreatment with parthenolide or QNZ demolished Resistin-enhanced TNF- α expression in HACECs. Pretreatment with parthenolide, but not QNZ, blocked Resistin-enhanced IL-1 β expression in HCAECs. Conclusion. Resistin may enhance inflammation by cross-talking with TLR4/NF- κ B signaling during the development of coronary arteritis in mice.

Inflammation of medium-sized, muscular arteries and coronary artery aneurysms are hallmarks of Kawasaki disease (KD), an acute, self-limited vasculitis of children. We previously reported that genetic variation in transforming growth factor (TGF)-β pathway genes influences both susceptibility to KD and coronary artery aneurysm (CAA) formation. TGF-β signaling has been implicated in the generation of myofibroblasts that influence collagen lattice contraction, antigen presentation, and recruitment of inflammatory cells as well as the generation of regulatory T-cells (Tregs). These processes could be involved in aneurysm formation and recovery in KD. Coronary artery tissues from 8 KD patient autopsies were stained to detect proteins in the TGF-β pathway, to characterize myofibroblasts, and to detect Tregs. Expression of proteins in the TGF-β pathway was noted in infiltrating mononuclear cells and spindle-shaped cells in the thickened intima and adventitia. Coronary arteries from an infant who died on Illness Day 12 showed α-smooth muscle actin (SMA)-positive, smoothelin-negative myofibroblasts in the thickened intima that co-expressed IL-17 and IL-6. CD8+ T-cells expressing HLA-DR+ (marker of activation and proliferation) were detected in the aneurysmal arterial wall. Forkhead box P3 (FOXP3), whose expression is essential for Tregs, was also detected in the nucleus of infiltrating mononuclear cells, suggesting a role for Tregs in recovery from KD arteritis.TGF-β may contribute to aneurysm formation by promoting the generation of myofibroblasts that mediate damage to the arterial wall through recruitment of pro-inflammatory cells. This multi-functional growth factor may also be involved in the induction of Tregs in KD., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Coronary artery aneurysms are rare complications of autosomal dominant polycystic kidney disease (ADPKD), and their pathogenesis remains poorly understood. We report an autopsy case of a 64-year-old ADPKD patient with an asymptomatic, large (4 cm in diameter) saccular aneurysm arising from the left circumflex (LCX) branch of the coronary artery with only mild atherosclerotic changes. Autopsy also revealed small, focal defects of media with or without microaneurysm formation in the LCX, mesenteric and renal arteries, and a fibromuscular dysplasia-like lesion with microaneurysm in the common iliac artery. Since polycystin-1 and -2 are expressed in arterial smooth-muscle cells, these findings imply that abnormal polycystin expression in ADPKD initially causes the focal medial defects, some of which might later progress to microaneurysms and then overt aneurysms. To the best of our knowledge, this is the first description of the pathologic findings of an ADPKD-associated coronary aneurysm and its probable precursor lesions in arteries., (© 2012 The Authors. Pathology International © 2012 Japanese Society of Pathology and Wiley Publishing Asia Pty Ltd.)

Background: Coronary artery lesions (CALs) late after Kawasaki disease were characterized by endothelial dysfunction and low-grade inflammation, surrogate markers for atherosclerosis. We tested the hypothesis that CALs in patients long after Kawasaki disease are accompanied by atheroma-like features, as assessed by virtual histology-intravascular ultrasound, a new method to assess coronary plaque composition and morphology in vivo., Methods and Results: Virtual histology-intravascular ultrasound was performed in 13 Japanese Kawasaki disease patients (median age, 18.3 years; interquartile range, 16.9 to 23.3 years) an interval after Kawasaki disease (median, 15.9 years; interquartile range, 14.3 to 21.9 years). We investigated 6 sites with localized stenosis, 15 sites with an aneurysm, 29 sites with a regressed aneurysm, and 50 sites with a normal coronary segment. Plaque components were categorized into 4 parts: fibrous, fibrofatty, necrotic core, and dense calcium areas. Qualitatively, the normal segment had no or trivial intravascular ultrasound-visible plaque area, whereas the CAL exhibited a heterogeneous plaque area with the 4 components in different amounts and proportions. Quantitatively, a combined group of CALs had a higher absolute value of fibrous, dense calcium, and necrotic core areas than the normal segment. In further analyses of 3 subtypes of CALs, localized stenosis, an advanced lesion, exhibited higher absolute and relative values of dense calcium and necrotic core areas and a lower relative value of the fibrous area than regressed and persistent aneurysms., Conclusions: The present limited but initial virtual histology-intravascular ultrasound findings give new insight into the potential role of atherogenesis in the evolution of CALs in adolescents and young adults long after Kawasaki disease and therefore warrant further investigation.

Kawasaki disease causes coronary artery lesions, such as dilatation, aneurysms, stenosis, and even occlusion in young children, and is one of the most common acquired heart diseases in developed countries. More than 10,000 new cases are reported in Japan every year. In its acute phase, severe coronary arteritis induces morphological changes in coronary arteries. Treatments for Kawasaki disease aim to eliminate coronary artery inflammation as quickly as possible to reduce the chance of causing coronary lesions. Immunoglobulin therapy with aspirin has become the standard therapy of first choice and helps attenuate coronary lesions. In addition to coronary artery disturbances in the acute phase, sclerotic vascular changes were observed in post-Kawasaki disease patients who did not have coronary lesions in the acute phase. Recent studies have revealed peripheral vasculature endothelial dysfunction in post-Kawasaki disease patients with and without coronary lesions. The risk factors for the development of atherosclerosis in adults, such as C-reactive protein, oxidative stress, and inflammatory cytokines, are also increased in the remote phase of Kawasaki disease. This morphological and functional endothelial dysfunction as Kawasaki disease vascular sequelae may suggest the early development of atherosclerosis in patients with Kawasaki disease. However, no direct evidence for this early development has been found so far. Kawasaki disease was first reported slightly more than 40 years ago. The first documented post-Kawasaki disease patients are now becoming old enough to have atherosclerosis. Some case reports suggest myocardial infarction with atherosclerotic changes in young adults who are believed to have a history of Kawasaki disease. This paper reviews Kawasaki disease from the perspective of long-term prognosis.

We report a case of Kawasaki disease with significant coronary artery aneurysms subsequently associated with reactive hemophagocytic lymphohistiocytosis in a young child with low T-cell perforin expression and NK-cell dysfunction. The patient was treated with a selective T-cell costimulation modulator in an effort to regulate T-cells. This case is unique for several reasons: (1) the severe degree of coronary artery aneurysms; (2) low T-cell perforin and NK-cell values; and (3) treatment with a selective T-cell costimulation modulator, none of which has been described in prior cases.

Background: Kawasaki disease (KD) is an infantile febrile illness of unknown origin characterized by clinical, laboratory and histopathologic features of systemic vasculitis., Methods and Results: We report a 3-month-old female infant with incomplete KD who suddenly died despite intravenous immunoglobulin, aspirin, steroid and heparin treatment. Postmortem examination confirmed the echocardiographically detected giant coronary aneurysms and showed occlusive thrombosis in the giant aneurysm of the left anterior descending coronary artery, associated with neoangiogenesis, macrophage infiltration and immunostaining for tissue factor (a strong initiator of the coagulation cascade), thrombopoietin receptor and tumour necrosis factor-alpha., Conclusions: These findings show the association of angiogenesis, tumor necrosis factor-alpha and procoagulant factors, with macrophage infiltration in coronary artery aneurysms of a fatal infantile KD.

Background: Kawasaki disease (KD) causes coronary artery disease (CAD) in children. In addition, a history of KD is suspected to be a risk factor for the development of atherosclerotic heart disease in the future. Histological senescence changes are a common denominator in atherosclerotic lesions in adults, so the present study investigated whether histological senescence changes had already occurred in KD aneurysm., Methods and Results: KD coronary aneurysms and internal mammary arteries retrieved from 5 children with KD (3, 4, 5, 6, and 11 years old, respectively) who underwent coronary artery bypass grafting, as well as giant coronary aneurysm size-reducing operations, were analyzed. Senescence-associated strong beta-galactosidase activity was observed in KD aneurysms, but not in the internal mammary arteries. An immunohistochemical analysis of the KD aneurysm using anti-CD31, anti-endothelial nitric oxide synthetase (eNOS), anti-vascular adhesion molecule-1 (VCAM-1), and anti-monocyte chemoattractant protein-1 (MCP-1) showed vascular endothelium CD31 staining, decreased staining of eNOS and strong staining of MCP-1 and VCAM-1. cDNA microarray gene expression profiling revealed increased MCP-1 expression in the KD aneurysm, a finding confirmed by quantitative polymerase chain reaction., Conclusions: Histological features of senescence and active remodeling gene expression show that the KD aneurysm is not a silent vasculitis terminal. The future fate of KD aneurysms, including atherosclerosis, should be monitored carefully.

Kawasaki disease is the most common cause of multisystem vasculitis in childhood. The resultant coronary artery lesions make Kawasaki disease the leading cause of acquired heart disease in children in the developed world. TNF-alpha is a pleiotropic inflammatory cytokine elevated during the acute phase of Kawasaki disease. In this study, we report rapid production of TNF-alpha in the peripheral immune system after disease induction in a murine model of Kawasaki disease. This immune response becomes site directed, with migration to the coronary arteries dependent on TNF-alpha-mediated events. Production of TNF-alpha in the heart is coincident with the presence of inflammatory infiltrate at the coronary arteries, which persists during development of aneurysms. More importantly, inflammation and elastin breakdown in the coronary vessels are completely eliminated in the absence of TNF-alpha effector functions. Mice treated with the TNF-alpha-blocking agent etanercept, as well as TNFRI knockout mice, are resistant to development of both coronary arteritis and coronary aneurysm formation. Taken together, TNF-alpha is necessary for the development of coronary artery lesions in an animal model of Kawasaki disease. These findings have important implications for potential new therapeutic interventions in children with Kawasaki disease.

Angiogenesis has been shown to be dysregulated in coronary artery (CA) aneurysms in the chronic phase of Kawasaki disease (KD). Neovascularization may occur in inflammatory-related vascular diseases because many angiogenesis mediators are secreted by inflammatory cells. We hypothesized that inflammation of the acute KD CA aneurysm could lead to dysregulation of angiogenesis mediators and subsequent neovascularization. To investigate this hypothesis, acute fatal KD cardiac tissues were immunostained for angiogenic inducers and inhibitors. Microvessel density was determined and the degree of inflammation assessed. Marked inflammation and angiogenesis were found in acute KD CA aneurysms and myocardium, with the highest microvessel density seen in patients who died 2-3 weeks after onset of the disease. Expression of proangiogenic proteins was higher than expression of inhibitors in KD CA aneurysms and myocardium. Angiogenesis mediators were localized to inflammatory cells in the myointima, adventitia, and myocardium. We conclude that significant neovascularization occurs in acute KD CA aneurysms and myocardium much sooner after onset of the disease than has been previously reported, that multiple angiogenesis factors are involved, and that dysregulation of angiogenesis likely contributes to KD vasculopathy.

Background: The pathogenesis of coronary artery aneurysm (CAA) formation in acute Kawasaki disease (KD) remains unclear. Cell adhesion molecules mediate cell-cell and cell-matrix interactions and regulate leukocyte migration, angiogenesis and tissue remodeling. We hypothesized that cell adhesion molecules are expressed in acute KD CAA., Methods: : P-selectin, E-selectin, vascular cell adhesion molecule-1 (VCAM-1) and integrin beta1 were immunolocalized in coronary arteries from 6 acute KD patients and 7 controls., Results: In endothelial cells of adventitial neovasculature in KD CAA, P-selectin and integrin beta1 were expressed in all of 6 patients, and E-selectin and/or VCAM-1 were expressed in 4 of 6. Endothelial cells in controls and in nonaneurysmal KD coronary arteries expressed P-selectin and integrin beta1, but not E-selectin or VCAM-1. Integrin beta1 was expressed on infiltrating leukocytes in 5 of 6 KD CAA and on fibroblasts in 6 of 6; these findings were absent in controls and in nonaneurysmal KD coronary arteries., Conclusions: The lack of widespread expression of E-selectin or VCAM-1 on endothelial cells of acute KD coronary arteries was surprising and suggests that inflammatory cell infiltration into KD coronaries is not simply the result of widespread up-regulation of cell adhesion molecules on endothelial cells by circulating cytokines. Rather, inflammatory cells may be directed to specific areas of the coronary arteries targeted by a pathogen causing KD. Our results suggest that E-selectin and VCAM-1 expression on neovasculature may contribute to neoangiogenesis and prolonged CAA inflammation and that integrin beta1 might be involved in fibroblastic remodeling of acute KD CAA.

Objectives: This study evaluated exercise performance and myocardial perfusion during exercise in patients with Kawasaki disease who had a broad spectrum of residual coronary abnormalities., Background: Reports of exercise performance after Kawasaki disease have generally included a small number of patients evaluated by various protocols, frequently with incomplete data. Myocardial perfusion studies have usually been limited to those using pharmacologically induced coronary vasodilation. Therefore, to our knowledge there has not been a large study directly correlating exercise performance, electrocardiographic (ECG) changes and myocardial perfusion imaging., Methods: Forty-six patients were classified into three groups on the basis of coronary artery status: group 1 (n = 27) had no objective evidence of coronary artery lesions; group 2 (n = 11) had resolved aneurysms; group 3 (n = 8) had persistent coronary aneurysms. All patients underwent exercise testing with monitoring of ECG changes and oxygen consumption. Single-photon emission computed tomographic imaging was performed at rest and during peak exercise using technetium-99m sestamibi., Results: Maximal oxygen consumption was within normal limits and was similar for all three groups. Five patients had mild ST segment changes at peak exercise. Two of these patients had stress-induced perfusion defects. Myocardial perfusion defects were present in 37% of patients in group 1, 63% in group 2 and 100% in group 3. Perfusion defects corresponded to the coronary artery lesion site in all but three patients., Conclusions: Maximal oxygen consumption is normal after Kawasaki disease regardless of coronary artery status. Stress-induced perfusion defects are frequent even in the absence of coronary abnormalities and are common in the absence of ST segment changes suggestive of ischemia.

The role of LTB4 in Kawasaki disease as a chemo-attractant and immunomodulator is reviewed through our own experience and reports by other investigators. In our experiment using 19 patients, we measured calcium ionophore-stimulated LTB4 synthesis in PMNs obtained in three different stages of the illness (acute, convalescent and recovered phases). LTB4 synthesis was significantly increased in the convalescent phase of the illness. Other investigators showed increased serum-LTB4 concentration in acute as well as convalescent phases, suggesting that LTB4 participated in the inflammatory process of Kawasaki disease as an inflammatory mediator and immunomodulator. However, no difference was found in LTB4 synthetic activity in PMNs in any phases of the illness between the patients with and without coronary lesions, which indicated that LTB4 was not a parameter of coronary aneurysm formation. Therapeutic use of high-dose gamma-globulin showed a tendency to decreased LTB4 synthesis in PMNs, although it is not conclusive.

Spontaneous coronary artery dissection is a rare disease with a higher prevalence in women, especially in the post-partum state. In one case, we attempted to relate this pathology to a disorder in collagen metabolism. A 32-year-old woman presented two episodes of myocardial infarction, 2 and 4 months after delivery which were shown to be due to two consecutive coronary artery dissections on coronary angiogram. Collagen metabolism was investigated in skin fibroblast cultures derived from the patient, and in control fibroblast cultures. After protein labelling in culture, total protein and collagen synthesis were determined. Quantification of procollagen synthesized in cell cultures and their rate of conversion into collagen were determined both in the culture media and a cell layer extract by DEAE cellulose chromatography. The results showed a reduced total collagen synthesis in the cultures of the patient in comparison with control cultures. The ratio between type I and III procollagen was not altered. The rate of conversion of procollagen into collagen was higher in the pathological cultures than in control cultures. Impaired collagen synthesis due perhaps to a change in hormonal equilibrium in the post-partum state might therefore have been responsible for coronary artery dissection.