Wild type cardiac amyloidosis: is it time to order a nuclear technetium pyrophosphate SPECT imaging study?

Transthyretin (ATTR) amyloidosis is a debilitating systemic disease often associated with symptomatic cardiac involvement. Diagnosis has dramatically changed with the advent of Technetium-99 m pyrophosphate (Tc-PYP) single-photon emission computed tomography (SPECT). With the ability to diagnose ATTR amyloidosis noninvasively and offer newer therapies, it is increasingly important to identify which patients should be referred for this testing. Relative apical sparing of longitudinal strain on echocardiogram can be potentially used to screen such patients. We sought to describe electrocardiogram (ECG) and echocardiogram (TTE) findings, including relative apical sparing of longitudinal strain, in ATTR amyloidosis patients diagnosed non-invasively with 99mTc-PYP imaging. This was a single-center, retrospective study with 64 patients who underwent 99mTc-PYP imaging between June 2016 and February 2019. Relative apical longitudinal strain was calculated from left ventricular longitudinal strain (LV LS) values. No ECG parameters were meaningfully associated with of 99 m Tc-PYP positive patients. LV mass index (p = 0.001), IVSd (p < 0.001), and LVPWd (< 0.001) demonstrated a highly significant difference between positive and negative 99mTc-PYP groups. 99mTc-PYP positive patients had a higher relative apical sparing of LV LS (p < 0.001), and notably, no 99mTc-PYP negative patient had a ratio > 1.0. The finding of relative apical sparing of longitudinal strain can reliably guide clinicians in triaging which patients to consider ordering 99mTc-PYP imaging for the noninvasive diagnosis of wild type cardiac amyloidosis. A patient with clinically suggestive features and an LV LS relative apical sparing ratio > 0.8 can be considered for 99mTc-PYP imaging to evaluate for ATTR cardiac amyloidosis.

Long-term clinical and angiographic outcomes of percutanenous coronary intervention with everolimus-eluting stents for the treatment of cardiac allograft vasculopathy.

BACKGROUND: Percutaneous coronary intervention (PCI) with bare-metal and first-generation drug-eluting stents (DES) for cardiac allograft vasculopathy (CAV) is associated with unexpectedly high restenosis rates and target lesion revascularization (TLR). Long-term outcomes of stenting for CAV using second-generation everolimus-eluting stents (EES) are not established. OBJECTIVE: To evaluate clinical and angiographic outcomes of CAV stenting with EES. METHODS: Patients who underwent PCI with EES for CAV were studied. Surveillance angiography was performed at 6-12 months post-PCI and as indicated. Patient survival, freedom from MACE, binary restenosis, TLR, target vessel revascularization (TVR), and non-TVR are reported. RESULTS: One-hundred and thirty two EES were placed in 113 discrete lesions in 48 patients. Pre-PCI stenosis was 82.1 ± 12.4%, and average stent length and diameter were 16.9 ± 5.7 and 3.0 ± 0.6 mm, respectively. Mean follow-up was 30.7 ± 18.8 months. Time from transplantation to PCI was 9.9 ± 5.1 years. Post-PCI survival at 1 (93.5 ± 3.6%), 2 (91.0 ± 4.3%), and 3 years (83.8 ± 6.3%), and freedom from MACE (87.2 ± 4.9%, 82.3 ± 5.7%, 75.8 ± 6.9%) were high. Binary restenosis at 1 (3.0 ± 1.7%), 2 (6.9 ± 3.2%), and 3 years (10.0 ± 4.3%) mirrored expected rates with EES use in native CAD. One-, two-, and three-year rates of TLR (5.1 ± 2.5%, 14.3 ± 4.6%, and 21.2 ± 6.3%), TVR (17.1 ± 4.5%, 39.0 ± 6.9%, and 46.2 ± 7.8%), and NTVR (26.3 ± 5.4%, 55.4 ± 7.0%, and 58.0 ± 7.0%) remain high. Diabetes was associated with an increased hazard ratio for binary restenosis 6.084 (95% CI 1.271-29.133, P = 0.024). CONCLUSIONS: PCI strategy using EES in the treatment of CAV was associated with a low binary restenosis rate, a high survival rate, and a high rate of freedom from MACE. However, at 3 years, TLR and TVR rates appeared similar to rates observed with first-generation DES. © 2016 Wiley Periodicals, Inc.

Induction Therapy With Antithymocyte Globulin in Patients Undergoing Cardiac Transplantation Is Associated With Decreased Coronary Plaque Progression as Assessed by Intravascular Ultrasound.

BACKGROUND: Antithymocyte globulin (ATG) is used as induction therapy after cardiac transplant for enhancing immunosuppression and delaying the initiation of nephrotoxic drugs. It is unknown if ATG induction is associated with decreased coronary plaque progression by intravascular ultrasound (IVUS). METHODS AND RESULTS: Patients transplanted between March 2010 and December 2012 with baseline and 1-year IVUS were included. All patients transplanted were included in a secondary analysis. Change in plaque progression was measured in a blinded fashion on matched coronary segments and contrasted between patients induced with ATG and those who were not. One hundred and three patients were included in IVUS arms. Mean age at transplant was 55.8 ± 12.6 years, and 33.0% were female. Patients induced with ATG were more sensitized (54.3% versus 14.3%). Plaque progression was attenuated in patients who received ATG by changes in maximal intimal area (1.0 ± 1.2 versus 2.3 ± 2.6 mm(2); P = 0.001), maximal percent stenosis (6.3 ± 7.9 versus 12.8 ± 12.3%; = 0.003), maximal intimal thickness (0.2 ± 0.2 versus 0.3 ± 0.3 mm; P = 0.035), and plaque volume (0.5 ± 0.7 versus 1.0 ± 1.3 mm(3)/mm; P = 0.016). Rapid plaque progression by maximal percent stenosis (≥ 20%) occurred less frequently in the ATG arm (4.3% versus 26.3; P = 0.003). Survival (P = 0.242) and any treated rejection (P = 0.166) were not statistically different between groups. Patients receiving ATG had a higher rate of first-year infection (P = 0.003), perhaps related to increased intravenous antibiotic use immediately postoperatively, and a trend toward more biopsy-proven rejection (P = 0.073). CONCLUSIONS: Induction therapy with ATG is associated with reduced first-year coronary plaque progression as assessed by IVUS, despite an increased prevalence of sensitized patients with a trend toward more rejection.

TSLP directly impairs pulmonary Treg function: association with aberrant tolerogenic immunity in asthmatic airway.

BACKGROUND: Even though thymic stromal lymphopoietin (TSLP) has been implicated in the development of allergic inflammation, its influence on immune tolerance mediated by regulatory T cells (Treg) have not been explored. We aimed to dissect the influence of TSLP on immunosuppressive activities of Treg and its potential consequences in human allergic asthma. METHODS: In vitro culture system was utilized to study the effects of TSLP on human Treg. The functional competency of pulmonary Treg from a cohort of 15 allergic asthmatic, 15 healthy control, and 15 non-allergic asthmatic subjects was also evaluated by suppression assays and flow cytometric analysis. RESULTS: Activated pulmonary Treg expressed TSLP-R and responded to TSLP-mediated activation of STAT5. TSLP directly and selectively impaired IL-10 production of Treg and inhibited their suppressive activity. In human allergic asthma, pulmonary Treg exhibited a significant decrease in suppressive activity and IL-10 production compared to healthy control and non-allergic asthmatic counterparts. These functional alterations were associated with elevated TSLP expression in bronchoalveolar lavage fluid (BAL) of allergic asthmatic subjects. Furthermore, allergic asthmatic BAL could suppress IL-10 production by healthy control pulmonary Treg in a TSLP-dependent manner. CONCLUSIONS: These results provide the first evidences for a direct role of TSLP in the regulation of suppressive activities of Treg. TSLP mediated inhibition of Treg function might present a novel pathologic mechanism to dampen tolerogenic immune responses in inflamed asthmatic airway.

Impaired IL-10-dependent induction of tolerogenic dendritic cells by CD4+CD25hiCD127lo/- natural regulatory T cells in human allergic asthma.

RATIONALE: Tolerogenic dendritic cells and natural regulatory T cells have been implicated in the process of infectious tolerance in human allergic asthma. However, the significance of the influence of natural regulatory T cells on tolerogenic dendritic cells in the disease has not been investigated. OBJECTIVES: We aimed to characterize the mechanism of induction of the tolerogenic phenotype in circulating blood dendritic cells by allergic asthmatic natural regulatory T cells. METHODS: The study was performed in a cohort of 21 subjects with allergic asthma, 21 healthy control subjects, and 21 subjects with nonallergic asthma. We cultured blood dendritic cells with natural regulatory T cells to study the induction of tolerogenic dendritic cells. Flow cytometry and proliferation assays were employed to analyze phenotype and function of dendritic cells as well as IL-10 production from natural regulatory T cells. MEASUREMENTS AND MAIN RESULTS: Dendritic cells cultured with natural regulatory T cells up-regulated IL-10, down-regulated costimulatory molecules, and stimulated the proliferation of CD4(+)CD25(-) effector T cells less potently. Allergic asthmatic natural regulatory T cells were significantly less efficient in inducing this tolerogenic phenotype of dendritic cells compared with healthy control and nonallergic asthmatic counterparts. Furthermore, this defective function of natural regulatory T cells was associated with their decreased IL-10 expression, disease severity, and could be reversed by oral corticosteroid therapy. CONCLUSIONS: These results provided the first evidences of impaired induction of tolerogenic dendritic cells mediated by natural regulatory T cells in human allergic asthma.

Selective deregulation in chemokine signaling pathways of CD4+CD25(hi)CD127(lo)/(-) regulatory T cells in human allergic asthma.

BACKGROUND: CD4+CD25(hi)CD127(lo)/(-) regulatory T cells have been suggested to be critical regulators of inflammatory processes in allergic asthma. Recent studies reported a selective decrease in the frequency of regulatory T cells in the bronchoalveolar lavage fluid of allergic asthmatic (AA) subjects, prompting the possibility of defective recruitment of these cells to the airway in response to chemokines produced during asthmatic inflammation. OBJECTIVES: This study aimed to characterize the chemotactic profile of circulating regulatory T cells in AA subjects in response to chemokines abundantly produced in airway inflammation, such as CCL1, CCL17, and CCL22. METHODS: The study was performed in a cohort of 26 AA, 16 healthy control, and 16 non-AA subjects. We used chemotaxis assays to evaluate cell migration, flow cytometry to examine chemokine receptor expression, and phospho-ELISA to study consequent signaling pathways in regulatory T cells. RESULTS: Regulatory T cells, but not CD4+CD25(-)T cells, from AA subjects showed decreased chemotactic responses, specifically to CCL1, in comparison with their healthy control and non-AA counterparts. Decreased CCL1-mediated chemotaxis in AA regulatory T cells was associated with decreased phosphorylation of protein kinase B (AKT), a protein involved in chemokine intracellular signaling. Furthermore, the decreased chemotactic response to CCL1 in AA regulatory T cells significantly correlated with asthma severity and decreased pulmonary function in AA subjects. CONCLUSIONS: These results provide the first evidence of dysfunction in the chemokine signaling pathway in AA regulatory T cells.

Abnormal glycosylation of Tamm-Horsfall protein in patients with interstitial cystitis.

OBJECTIVE: To confirm abnormal glycosylation of Tamm-Horsfall protein (THP) in patients with interstitial cystitis (IC). PATIENTS, SUBJECTS AND METHODS: The sialic acid content of THP, a critical component of its biological activity, is reduced in patients with IC. N-glycan shows reduced levels of high molecular weight tri- and tetra-antennary sialylated oligosaccharides. These results are supported by quantitative monosaccharide analysis of neutral and amino sugars in patients vs control subjects. THP was isolated from urine samples of 23 patients with IC and 24 control subjects by salt precipitation. The sialic acid contents were measured using 1,2-diamino-4,5-methylene dioxybenzene-high performance liquid chromatography analysis. For N-glycan profiling, purified THP was treated with peptide:N-glycosidase F to release N-glycans. The purified N-glycans were labelled with 2-aminobenzamide and were profiled by high-pH anion exchange chromatography (HPAEC) with fluorescence detection. The neutral and amino sugars were determined by HPAEC with pulsed amperometric detection. RESULTS: The total sialic acid in patients was half of that in controls. There was a pattern of reduced level of high molecular weight sialylated oligosaccharide in 17 of 23 patients vs four of 24 controls. The total neutral and amino sugars showed a approximately 30% reduction in patients. The mean (sem) for the controls was 133.79 (6.51) vs 94.76 (6.67) nmol/200 microg of THP for patients (P < 0.001). CONCLUSIONS: THP in patients with IC has reduced sialylation and overall glycosylation, and by inference, THP has a role in the pathophysiology of IC.