Validation of the Diagnostic Criteria for IgG4-Related Periaortitis/Periarteritis and Retroperitoneal Fibrosis (IgG4PA/RPF) 2018, and Proposal of a Revised 2023 Version for IgG4-Related Cardiovascular/Retroperitoneal Disease.

BACKGROUND: In 2018, diagnostic criteria were introduced for IgG4-related periaortitis/periarteritis and retroperitoneal fibrosis (PA/RPF). This study assessed the existing criteria and formulated an improved version.Methods and Results: Between August 2022 and January 2023, we retrospectively analyzed 110 Japanese patients diagnosed with IgG4-related disease (IgG4-RD) involving cardiovascular and/or retroperitoneal manifestations, along with 73 non-IgG4-RD patients ("mimickers") identified by experts. Patients were stratified into derivation (n=88) and validation (n=95) groups. Classification as IgG4-RD or non-IgG4-RD was based on the 2018 diagnostic criteria and various revised versions. Sensitivity and specificity were calculated using experts' diagnosis as the gold standard for the diagnosis of true IgG4-RD and mimickers. In the derivation group, the 2018 criteria showed 58.5% sensitivity and 100% specificity. The revised version, incorporating "radiologic findings of pericarditis", "eosinophilic infiltration or lymphoid follicles", and "probable diagnosis of extra-PA/-RPF lesions", improved sensitivity to 69.8% while maintaining 100% specificity. In the validation group, the original and revised criteria had sensitivities of 68.4% and 77.2%, respectively, and specificities of 97.4% and 94.7%, respectively. CONCLUSIONS: Proposed 2023 revised IgG4-related cardiovascular/retroperitoneal disease criteria show significantly enhanced sensitivity while preserving high specificity, achieved through the inclusion of new items in radiologic, pathological, and extra-cardiovascular/retroperitoneal organ categories.

The 2020 revised comprehensive diagnostic (RCD) criteria for IgG4-RD.

IgG4-related disease (IgG4-RD) is a fascinating clinical entity first reported in this century in Japan, and includes a wide variety of diseases, such as formerly named Mikulicz's disease (MD), autoimmune pancreatitis (AIP), interstitial nephritis, prostatitis and retroperitoneal fibrosis. The Japanese IgG4 team organized by the Ministry of Health, Labor and Welfare (MHLW) of Japan has published the first criteria, comprehensive diagnostic (CD) criteria for IgG-RD 2011. Thereafter, IgG4-RD has been accepted widely and many cases have been reported from all over the world. Several problems have arisen in clinical practice, however, including the difficulty obtaining biopsy samples, and the sensitivity and specificity in cut off level of serum IgG4 and impaired immunostaining of IgG4. Given these situations, the Japanese IgG4 team has updated the 2011 comprehensive diagnostic criteria for IgG4-RD and propose the 2020 revised comprehensive diagnostic (RCD) criteria for IgG4-RD, which consists of 3 domains; 1) Clinical and radiological features, 2) Serological diagnosis and 3) Pathological diagnosis. In addition, the new pathological diagnosis is composed by three sub-items including storiform fibrosis and obliterative phlebitis.

RadioGraphics Update: IgG4-related Cardiovascular Disease from the Aorta to the Coronary Arteries.

Editor's Note.- Articles in the RadioGraphics Update section provide current knowledge to supplement or update information found in full-length articles previously published in RadioGraphics. Authors of the previously published article provide a brief synopsis that emphasizes important new information such as technologic advances, revised imaging protocols, new clinical guidelines involving imaging, or updated classification schemes. Articles in this section are published solely online and are linked to the original article.

Febuxostat does not delay progression of carotid atherosclerosis in patients with asymptomatic hyperuricemia: A randomized, controlled trial.

BACKGROUND: An elevated level of serum uric acid (SUA) is associated with an increased risk of cardiovascular disease. Pharmacological intervention with urate-lowering agents, such as the conventional purine analogue xanthine oxidase (XO) inhibitor, allopurinol, has been used widely for a long period of time in clinical practice to reduce SUA levels. Febuxostat, a novel non-purine selective inhibitor of XO, has higher potency for inhibition of XO activity and greater urate-lowering efficacy than conventional allopurinol. However, clinical evidence regarding the effects of febuxostat on atherosclerosis is lacking. The purpose of the study was to test whether treatment with febuxostat delays carotid intima-media thickness (IMT) progression in patients with asymptomatic hyperuricemia. METHODS AND FINDINGS: The study was a multicenter, prospective, randomized, open-label, blinded-endpoint clinical trial undertaken at 48 sites throughout Japan between May 2014 and August 2018. Adults with both asymptomatic hyperuricemia (SUA >7.0 mg/dL) and maximum IMT of the common carotid artery (CCA) ≥1.1 mm at screening were allocated equally using a central web system to receive either dose-titrated febuxostat (10-60 mg daily) or as a control-arm, non-pharmacological lifestyle modification for hyperuricemia, such as a healthy diet and exercise therapy. Of the 514 enrolled participants, 31 were excluded from the analysis, with the remaining 483 people (mean age 69.1 years [standard deviation 10.4 years], female 19.7%) included in the primary analysis (febuxostat group, 239; control group, 244), based on a modified intention-to-treat principal. The carotid IMT images were recorded by a single sonographer at each site and read in a treatment-blinded manner by a single analyzer at a central core laboratory. The primary endpoint was the percentage change from baseline to 24 months in mean IMT of the CCA, determined by analysis of covariance using the allocation adjustment factors (age, gender, history of type 2 diabetes, baseline SUA, and baseline maximum IMT of the CCA) as the covariates. Key secondary endpoints included changes in other carotid ultrasonographic parameters and SUA and the incidence of clinical events. The mean values (± standard deviation) of CCA-IMT were 0.825 mm ± 0.173 mm in the febuxostat group and 0.832 mm ± 0.175 mm in the control group (mean between-group difference [febuxostat - control], -0.007 mm [95% confidence interval (CI) -0.039 mm to 0.024 mm; P = 0.65]) at baseline; 0.832 mm ± 0.182 mm in the febuxostat group and 0.848 mm ± 0.176 mm in the control group (mean between-group difference, -0.016 mm [95% CI -0.051 mm to 0.019 mm; P = 0.37]) at 24 months. Compared with the control group, febuxostat had no significant effect on the primary endpoint (mean percentage change 1.2% [95% CI -0.6% to 3.0%] in the febuxostat group (n = 207) versus 1.4% [95% CI -0.5% to 3.3%] in the control group (n = 193); mean between-group difference, -0.2% [95% CI -2.3% to 1.9%; P = 0.83]). Febuxostat also had no effect on the other carotid ultrasonographic parameters. The mean baseline values of SUA were comparable between the two groups (febuxostat, 7.76 mg/dL ± 0.98 mg/dL versus control, 7.73 mg/dL ± 1.04 mg/dL; mean between-group difference, 0.03 mg/dL [95% CI -0.15 mg/dL to 0.21 mg/dL; P = 0.75]). The mean value of SUA at 24 months was significantly lower in the febuxostat group than in the control group (febuxostat, 4.66 mg/dL ± 1.27 mg/dL versus control, 7.28 mg/dL ± 1.27 mg/dL; mean between-group difference, -2.62 mg/dL [95% CI -2.86 mg/dL to -2.38 mg/dL; P < 0.001]). Episodes of gout arthritis occurred only in the control group (4 patients [1.6%]). There were three deaths in the febuxostat group and seven in the control group during follow-up. A limitation of the study was the study design, as it was not a placebo-controlled trial, had a relatively small sample size and a short intervention period, and only enrolled Japanese patients with asymptomatic hyperuricemia. CONCLUSIONS: In Japanese patients with asymptomatic hyperuricemia, 24 months of febuxostat treatment did not delay carotid atherosclerosis progression, compared with non-pharmacological care. These findings do not support the use of febuxostat for delaying carotid atherosclerosis in this population. TRIAL REGISTRATION: University Hospital Medical Information Network Clinical Trial Registry UMIN000012911.

Cardiac Regeneration by Statin-Polymer Nanoparticle-Loaded Adipose-Derived Stem Cell Therapy in Myocardial Infarction.

Clinical trials with autologous adipose-derived stem cell (AdSC) therapy for ischemic heart diseases (IHDs) are ongoing. However, little is known about combinational therapeutic effect of AdSCs and statin poly(lactic-co-glycolic) acid (PLGA) nanoparticles on the ischemic myocardium. We investigated the hypothesis that statins, which have pleiotropic effects, augment the therapeutic potential of AdSCs and that AdSCs also act as drug delivery tools. Simvastatin-conjugated nanoparticles (SimNPs) significantly promoted migration activity without changing proliferation activity and upregulated growth factor gene expression in vitro. A small number of intravenously administered SimNP-loaded AdSCs (10,000 cells per mouse) improved cardiac function following myocardial infarction, inducing endogenous cardiac regeneration in the infarcted myocardium. The de novo regenerated myocardium was thought to be derived from epicardial cells, which were positive for Wilms' tumor protein 1 expression. These findings were attributed to the sustained, local simvastatin release from the recruited SimNP-loaded AdSCs in the infarcted myocardium rather than to the direct contribution of recruited AdSCs to tissue regeneration. SimNP-loaded AdSCs may lead to a novel somatic stem cell therapy for IHDs. Stem Cells Translational Medicine 2019;8:1055-1067.

IgG4-Positive Plasmacytic Infiltration in Aortic Wall and Aortic Valve Surgical Samples and Its Relation to Preoperative Serum IgG4 Levels.

The prevalence and extent of immunoglobulin G4 (IgG4)-positive cell infiltration were investigated in 282 surgical samples of aortic wall and aortic valve. Tissue infiltration of IgG4-positive cells was observed in 24 (17.3%) of 139 aortic valve samples and 46 (32%) of 143 aortic wall samples, and the condition of IgG4-positive cell infiltration > 30/hpf together with IgG4/CD138 ratio > 40% was observed in 2 (1.4%) of aortic valve samples and 14 (9.8%) of aortic wall samples. Among 275 patients, preoperative serum IgG4 level was available in 48 patients (50 samples), and it was > 135 mg/dL in only one patient. Of these 48 patients with serum IgG4 measurement, 29 patients had aortic valve stenosis and 12 had aortic aneurysm. Compared with 23 aortic stenosis patients without tissue infiltration of IgG4-positive cells in the aortic valve, six patients with IgG4-positive cell infiltration had a more prevalent smoking history (26% versus 83%) and borderline significantly higher serum IgG4 (median, 24.5 mg/dL versus 55.5 mg/dL), although either preoperative peak pressure gradient between left ventriculum and aorta or aortic valve area did not differ significantly between groups. Compared with six aortic aneurysm patients without tissue infiltration of IgG4-positive cells in the aortic wall, six patients with IgG4-positive cell infiltration had borderline significantly higher serum IgG4 (median, 28.9 mg/dL versus 68.2 mg/dL). The current study showed that tissue IgG4-positive infiltration is not a rare occurrence in the aortic stenosis and aortic aneurysm. Clinical significance of tissue IgG4-postive cell infiltration in these patients requires further investigation.

Improved diagnosis of the number of stenosed coronary artery vessels by segmentation with scatter and photo-peak window data for attenuation correction in myocardial perfusion SPECT.

BACKGROUND: Attenuation correction using segmentation of scatter and photo-peak window data (SSPAC) enables an evaluation of the attenuation map in a patient-specific manner without additional radiation exposure. We compared the accuracy of SSPAC and non-corrected myocardial perfusion scintigraphy methods for diagnosing the number of stenosed coronary artery vessels. METHODS AND RESULTS: We retrospectively reviewed the data from 183 consecutive patients who underwent 99mTc-tetrofosmin stress/rest SPECT examination and a coronary angiography within 3 months. The MPS images were reconstructed with and without SSPAC attenuation correction. We examined the accuracy of the quantitative interpretation using summed differential score in the detection of coronary artery disease (CAD). The attenuation maps were successfully determined in 179 of 183 patients (98%). In terms of the vessel-based diagnostic ability, sensitivity, specificity, positive predictive and negative predictive values of the SSPAC and non-correction methods for diagnosing CAD in individual coronary territories were 77%*, 89%, 74%*, and 90%* vs 51%, 87%, 62%, and 82%, respectively (*P < .05). In 35 patients with multi-vessel CAD, those values were 78%*, 81%, 93%, and 55%* vs 49%, 81%, 89%, and 34%, respectively (*P < .05; AUC: 0.82 vs 0.62, P < .05). CONCLUSION: SSPAC-corrected SPECT myocardial perfusion images exhibit improved accuracy in the detection of the number of stenosed coronary artery vessels, even in patients with multi-vessel CAD.

IgG4-related periaortitis/periarteritis: An under-recognized condition that is potentially life-threatening.

Periaortitis and periarteritis are one of the clinical features of IgG4-related disease. Such vascular manifestations are reported to be present in 10-30% of overall IgG4-related disease, and they may also appear as an isolated lesion of IgG4-related disease. As other types of large vessel vasculitis, IgG4-related vasculitis may cause significant clinical consequences. On the other hand, the diagnosis of IgG4-related periaortitis/periarteritis seems to have been made on the basis of different diagnostic criteria in reported studies; thus far, difficulty seems to be present in assessing the true frequency of the disease as well as determining the optimal therapeutic strategy. In this review, in addition presenting the clinical and pathological features of IgG4-related periaortitis/periarteirtis, we would like to discuss on what kind of points should be resolved for the better understanding of vascular involvement of IgG4-related disease in terms of diagnosis and treatment.

Clinical and Pathological Characteristics of IgG4-Related Periaortitis/Periarteritis and Retroperitoneal Fibrosis Diagnosed Based on Experts' Diagnosis.

IgG4-related disease is a systemic disease, characterized by elevation of serum IgG4 and, histopathologically, massive infiltration of IgG4+ lymphocyte and plasma cell infiltration, storiform fibrosis, causing enlargement, nodules or thickening. It may affect various organs simultaneously or metachronously. Here we analyzed the clinical and pathological characteristics of 99 patients diagnosed with IgG4-related periaortitis/periarteritis and retroperitoneal fibrosis. Of 99 patients (women/men, 15/84; mean age 67.3±9.5 years), 33 were diagnosed based on the histopathological findings of perivascular/retroperitoneal lesions, 50 were diagnosed based on the characteristic imaging findings of perivascular/retroperitoneal lesions and the presence of definitive IgG4-related disease in other organ(s), and the remaining 16 patients were diagnosed by experts based on the characteristic imaging findings of perivascular/retroperitoneal legions, serological findings, response to glucocorticoid treatment, and/or the presence of suspected IgG4-related disease in other organ(s). According to the new organ-specific criteria proposed by experts, 73 (73.7%) diagnoses were categorized to be definitive, and 6 (6.1%) and 17 (17.2%) diagnoses were categorized to be probable and possible, respectively. Further analyses are needed to clarify the optimal diagnostic and therapeutic strategy of IgG4-related periaortitis/periarteritis and retroperitoneal fibrosis. (This is a translation of J Jpn Coll Angiol 2018; 58: 117-129.).

A Case of Aortic Stenosis with Serum IgG4 Elevation, and IgG4-Positive Plasmacytic Infiltration in the Aortic Valve, Epicardium, and Aortic Adventitia.

A 74-year-old man was admitted for preoperative screening of aortic stenosis. Five months before this admission, he was found to have elevated serum immunoglobulin G4 (IgG4; 2,010 mg/dL). Computed tomography (CT) showed a soft tissue mass surrounding the abdominal aorta, suggestive of IgG4-related periaortitis. CT coronary angiography showed perivascular thickening of the right coronary artery, and subsequent coronary angiography showed a multi-vessel disease. The patient underwent aortic valve replacement and coronary bypass surgery. Immunohistochemical analysis showed IgG4-positive plasmacytic infiltration in specimens from the aortic valve, epicardium, and aortic adventitia, suggestive of the possible role of IgG4-related immune inflammation for the pathogenesis.

Spontaneous Reduction in Abnormal Myocardial Uptake of Fluorine-18 Fluorodeoxygluose in a Patient with Cardiac Sarcoidosis.

Fluorine-18 fluorodeoxygluose (18F-FDG) positron emission tomography (PET) is a useful tool for evaluating disease activity in sarcoidosis including cardiac involvement. A 67-year-old patient who developed atrioventricular block requiring permanent pacemaker implantation was diagnosed with cardiac sarcoidosis. The patient did not undergo steroid or immunosuppressive therapy but underwent serial 18F-FDG PET examination, which showed spontaneous reduction in the myocardial FDG uptake, indicating the remission of immune-inflammatory activity. Although the global systolic function remained preserved, thinning of the septal wall emerged during the clinical course of follow-up, which is characteristic for cardiac sarcoidosis.

The Prevalence and Findings of Subclinical Influenza-associated Cardiac Abnormalities among Japanese Patients.

Objective Although life-threatening cardiac complications in influenza infection are rare, subclinical influenza-associated cardiac abnormalities may occur more frequently. We investigated the prevalence of subclinical cardiac findings. Methods After obtaining their written informed consent, 102 subjects were enrolled in the present study. The study subjects underwent a first set of examinations, which included electrocardiography (ECG), echocardiography, and the measurement of their cardiac enzyme levels. Those with one or more abnormal findings among these examinations were encouraged to undergo a repeat examination 2 weeks later. Results Among the 102 subjects enrolled, 22 (21.6%) were judged to have cardiac findings, including ST-T abnormalities, pericardial effusion, diastolic dysfunction, and cardiac enzyme elevation. Eighteen of these 20 subjects underwent a second screening at a median of 14 days later, and it was found that 11 of the 18 subjects were free from cardiac findings on this second examination. This suggested that the abnormalities were only transient and they therefore might have been associated with influenza. Approximately 20% of the influenza patients enrolled had cardiac findings, including ST-T segment abnormalities, pericardial effusion, and cardiac enzyme elevation. Conclusion Among the 102 patients who were studied, the cardiac findings were only mild and transient; however, physicians should be aware of influenza infection-associated cardiac abnormalities because such abnormalities may not be rare.

Prevalence of Elevated Serum IgG4 Level among Patients Diagnosed or Suspected with Cardiovascular Disorders.

Immunoglobulin G4 (IgG4)-related disease, that is characterized by the elevation of circulating IgG4 level and the tissue-infiltration of IgG4-positive plasma cells, can target the cardiovascular tissue, although the diagnosis of IgG4-related cardiovascular lesion is not easy owing to the substantial risk for the tissue sampling. We herein examined the serum IgG4 levels among cardiac patients. In patients who were admitted to the cardiology department (n=477) and those who underwent computed tomography coronary artery angiography (n=401), elevated serum IgG4 level (≥135 mg/dL) was found 23 (4.8%) and 17 (4.2%), respectively. However, among those with elevated serum IgG4, only two patients could be clinicopathologically diagnosed with IgG4-related disease. Cardiovascular organ involvement may aggravate the prognosis of IgG4-related disease which in general not life-threatening. Considering that the non-negligible prevalence of high IgG4 level among cardiac patients who were not diagnosed with IgG4-related disease, however, physicians should not count too much on the serum IgG4 levels for the diagnosis of IgG4-related cardiovascular lesions, especially when histopathologic findings are not available, or when other-tissue involvement of IgG4-related disease is not apparent. (This is a translation of J Jpn Coll Angiol 2017; 57: 91-98.).

High serum bilirubin is associated with lower prevalence of peripheral arterial disease among cardiac patients.

Several studies have shown that subjects with higher serum bilirubin may have a lower risk of cardiovascular disorders. We herein investigated whether serum bilirubin concentration is associated with lower extremity ischemia among cardiology patients. In total, 935 patients without a history of angioplasty or bypass surgery of the lower limb arteries and who had bilateral ankle-brachial index measurements were included in the study. Peripheral arterial disease (PAD) was defined to be present when ABI of either or both sides was <0.9. Overall, the serum total bilirubin concentration ranged between 0.1 and 2.7mg/dL (normal range, 0.1-1.0mg/dL). Across the bilirubin tertiles, age did not differ significantly. On the other hand, male patients (median 0.6mg/dL, interquartile range (IQR) 0.4-0.7mg/dL) had significantly higher bilirubin levels than female patients (median 0.5mg/dL, IQR 0.4-0.7mg/dL, P=0.014). Logistic regression analysis showed that, as compared with the lowest bilirubin tertile (0.1-0.4mg/dL), the highest tertile (0.7-2.7mg/dL) was significantly negatively associated with prevalent PAD after adjusting for sex, age, eGFR, white blood cell count, inorganic phosphate, HbA1C, total and HDL cholesterol, triglycerides, current smoking, diabetic medication, and statin use. This association remained significant when only those with serum bilirubin in the normal range were included in the analysis. Among cardiology patients, serum bilirubin concentration was significantly negatively associated with prevalence of PAD. The underlying mechanism and therapeutic indications should be investigated in further investigations.

Changes in Serum Fibroblast Growth Factor 23 in Patients With Acute Myocardial Infarction.

BACKGROUND: Fibroblast growth factor 23 (FGF23) induces cardiac remodeling. We investigated the changes in serum FGF23 levels in patients diagnosed with acute myocardial infarction (AMI).Methods and Results:A total of 44 patients diagnosed with AMI were included in the current study. All patients underwent emergency percutaneous coronary intervention (PCI). The median of peak creatine kinase (CK) and CKMB values was 1,816 U/L and 159 U/L, respectively. Serum levels of FGF23, calcium, and inorganic phosphate (iP) were measured before PCI, and on days 1, 3, 5, 7 after PCI. Serum FGF23 levels showed a slight, but significant decrease on days 1 and 3 after PCI, and a 1.5- and 2.0-fold increase on days 5 and 7, respectively, after PCI. As compared with propensity score-matched patients without AMI, serum FGF23 was significantly lower among the current cohort of AMI patients. In 22 subjects who underwent a follow-up echocardiographic examination at 6 months after the onset of AMI, the log-transformed relative increase in FGF23 on day 7 significantly and negatively correlated with changes between LVEF on admission and that at 6 months afterward. CONCLUSIONS: After a slight decrease on days 1 and 3 after admission, serum FGF23 increased significantly on days 5 and 7. The underlying mechanism and potential clinical importance of these observations require further investigation.

IgG4-related Disease - A Systemic Disease that Deserves Attention Regardless of One's Subspecialty.

IgG4-related disease (IgG4-RD) is an inflammatory condition characterized by a high serum IgG4 concentration and the abundant infiltration of lymphocytes and IgG4-positive plasma cells in the tissue, as well as spatial (diverse clinical manifestations) and temporal (the possibility of recurrence) multiplicities. Since the initial documentation of IgG4-related disease in patients with autoimmune pancreatitis in 2001, a growing body of evidence has been accumulating to suggest that various-virtually all-organs can be affected by IgG4-RD. In general, steroid therapy is effective and is considered to be the first-line treatment for IgG4-RD. The precise mechanism underlying this systemic disorder has remained unknown. Considering that IgG4-RD was specified as being an intractable disease in 2015, further studies are needed to clarify whether IgG4-RD is indeed a distinct disease entity or a complex of disorders of different etiologies and clinical conditions.