Somatostatin Receptor PET/MR Imaging of Inflammation in Patients With Large Vessel Vasculitis and Atherosclerosis.

BACKGROUND: Assessing inflammatory disease activity in large vessel vasculitis (LVV) can be challenging by conventional measures. OBJECTIVES: We aimed to investigate somatostatin receptor 2 (SST2) as a novel inflammation-specific molecular imaging target in LVV. METHODS: In a prospective, observational cohort study, in vivo arterial SST2 expression was assessed by positron emission tomography/magnetic resonance imaging (PET/MRI) using 68Ga-DOTATATE and 18F-FET-ßAG-TOCA. Ex vivo mapping of the imaging target was performed using immunofluorescence microscopy; imaging mass cytometry; and bulk, single-cell, and single-nucleus RNA sequencing. RESULTS: Sixty-one participants (LVV: n = 27; recent atherosclerotic myocardial infarction of ≤2 weeks: n = 25; control subjects with an oncologic indication for imaging: n = 9) were included. Index vessel SST2 maximum tissue-to-blood ratio was 61.8% (P < 0.0001) higher in active/grumbling LVV than inactive LVV and 34.6% (P = 0.0002) higher than myocardial infarction, with good diagnostic accuracy (area under the curve: ≥0.86; P < 0.001 for both). Arterial SST2 signal was not elevated in any of the control subjects. SST2 PET/MRI was generally consistent with 18F-fluorodeoxyglucose PET/computed tomography imaging in LVV patients with contemporaneous clinical scans but with very low background signal in the brain and heart, allowing for unimpeded assessment of nearby coronary, myocardial, and intracranial artery involvement. Clinically effective treatment for LVV was associated with a 0.49 ± 0.24 (standard error of the mean [SEM]) (P = 0.04; 22.3%) reduction in the SST2 maximum tissue-to-blood ratio after 9.3 ± 3.2 months. SST2 expression was localized to macrophages, pericytes, and perivascular adipocytes in vasculitis specimens, with specific receptor binding confirmed by autoradiography. SSTR2-expressing macrophages coexpressed proinflammatory markers. CONCLUSIONS: SST2 PET/MRI holds major promise for diagnosis and therapeutic monitoring in LVV. (PET Imaging of Giant Cell and Takayasu Arteritis [PITA], NCT04071691; Residual Inflammation and Plaque Progression Long-Term Evaluation [RIPPLE], NCT04073810).

Use of Glomerular CD68+ Cells as a Surrogate Marker for Endocapillary Hypercellularity in Lupus Nephritis.

Introduction: Lupus nephritis (LN) class III or IV is strongly related to patient mortality and morbidity. The interobserver agreement of endocapillary hypercellularity by routine light microscopy, one of the most important lesions determining whether class III or IV is present, is moderate. In IgA nephropathy (IgAN), the presence of glomerular CD68+ cells was found to be a good surrogate marker for endocapillary hypercellularity. We investigated whether the presence of glomerular CD68+ cells could serve as a surrogate marker for endocapillary hypercellularity as well in LN. Methods: A total of 92 LN biopsies were scored for the number of glomerular CD68+ cells using CD68 staining, including endocapillary hypercellularity and the activity index (AI). A new AI was calculated in which CD68+ cells replaced endocapillary hypercellularity. Clinical parameters were obtained from time of biopsy, 1 year after, and 2 years after. Results: The number of glomerular CD68+ cells significantly correlated with endocapillary hypercellularity. A cutoff value of 7 for the maximum number of CD68+ cells within 1 glomerulus in a biopsy yielded a sensitivity of 88% and a specificity of 67% for the presence of endocapillary hypercellularity. Both endocapillary hypercellularity and CD68+ cells correlated with renal function during follow-up. The current and the new AI correlated equally well with the clinical outcome. Conclusion: In LN, CD68+ cells can be used as a surrogate marker for endocapillary hypercellularity.

Efficacy, pharmacokinetic and pharmacodynamic profile of belimumab for systemic lupus erythematosus.

INTRODUCTION: Systemic lupus erythematosus (SLE) is a severe autoimmune disease and a sizeable proportion of patients remain refractory to currently available immunosuppressive agents. The burden of uncontrolled disease is significant as disease flare and persistent inflammation lead to long-term damage accrual and increased morbidity. Belimumab , a humanized monoclonal antibody that inhibits B-lymphocyte stimulator (BLyS), is the first drug to be approved by the US FDA for the treatment of SLE in 50 years. AREAS COVERED: In this review, we provide an overview of novel therapeutic agents under development for the treatment of SLE, a description of the pharmacodynamic and pharmacokinetic properties of belimumab, evidence of efficacy of belimumab as demonstrated in clinical trials, safety and tolerability data and a summary of ongoing clinical trials of belimumab in SLE. This information was amassed following a comprehensive MEDLINE and Cochrane library search. Ongoing clinical trial information was obtained from ClinicalTrials.gov. EXPERT OPINION: Two, large Phase III trials have demonstrated the clinical efficacy of belimumab in musculoskeletal, mucocutaneous, haematologic and constitutional features of SLE. Patients with severe disease manifestations such as lupus nephritis and CNS disease were excluded from these trials and hence the role of belimumab in the overall management of SLE has yet to be established. Studies in lupus nephritis are ongoing.

Progress with the use of monoclonal antibodies for the treatment of systemic lupus erythematosus.

In recent years, significant progress has been made in the use of monoclonal antibodies in the treatment of systemic lupus erythematosus (SLE). Advances in our understanding of the complexity of SLE immunopathogenesis have led to the testing of several biologic agents in clinical trials. Monoclonal therapies currently emerging or under development include B-cell depletion therapies, agents targeting B-cell survival factors, blockade of T-cell co-stimulation and anticytokine therapies. Issues remain, however, regarding clinical trial design and outcome measures in SLE which need to be addressed to optimize translation of these promising therapies into clinical practice.

Belimumab for the treatment of systemic lupus erythematosus.

Given their pivotal role in autoantibody production, B-cells have become an attractive therapeutic target in systemic lupus erythematosus (SLE). Belimumab, a fully human monoclonal antibody against B lymphocyte stimulator (BLyS), a B-cell survival factor, was licensed in 2011 for the treatment of autoantibody-positive SLE. The BLISS-52 and BLISS-76 Phase III trials successfully demonstrated that belimumab (10 mg/kg) with standard therapy significantly decreased disease activity in SLE patients compared to placebo with standard therapy. Overall, belimumab has been found to be safe and well tolerated. While the BLISS-52 and BLISS-76 studies are the largest clinical trials in SLE to date, they mainly focused on musculoskeletal, mucocutaneous, hematologic and general constitutional features of the disease. Patients with severe lupus nephritis and severe central nervous system disease were excluded from these trials. Studies of belimumab in lupus nephritis are ongoing that may clarify the role of this agent in the clinical management of SLE.

Association of thrombotic microangiopathy and intimal hyperplasia with bleeding post-renal biopsy in antiphospholipid antibody-positive patients.

OBJECTIVE: Renal biopsy remains the gold standard investigation for both diagnostic and prognostic purposes in the clinical management of lupus nephritis. However, it is not without potentially significant complications. The objectives of this study were to determine the rate of significant bleeding post-renal biopsy in patients with lupus nephritis and to identify risk factors associated with hemorrhagic complications. METHODS: Clinical data were retrospectively collected on 215 renal biopsies performed over a 13-year period (1999-2012). Patients were categorized into 3 groups: a diagnosis of systemic lupus erythematosus (SLE) alone, SLE with coexisting antiphospholipid syndrome (APS), or a diagnosis of SLE with either positive anticardiolipin antibodies and/or lupus anticoagulant (LAC) without clinical APS manifestations. RESULTS: Major bleeding complications were significantly more common in those with coexisting APS and/or antiphospholipid antibodies (aPL). LAC, presence of thrombotic microangiopathy (TMA) on renal biopsy, older age at the time of the biopsy (age >40 years), and elevated serum creatinine (>400 µmoles/liter) were independent risk factors for increased risk of bleeding. TMA and severe fibrous intimal hyperplasia on renal biopsy were significantly more prevalent in those who developed severe bleeding complications. CONCLUSION: Based on these findings, lupus nephritis patients with coexisting APS, positive LAC, and histologic evidence of TMA and/or fibrous intimal hyperplasia are at increased risk of bleeding post-renal biopsy. aPL should be checked in all lupus nephritis patients before undergoing renal biopsy, as this subset of patients warrants particular caution pre- and postprocedure.

Novel therapeutic agents in clinical development for systemic lupus erythematosus.

Conventional immunosuppressive therapies have radically transformed patient survival in systemic lupus erythematosus (SLE), but their use is associated with considerable toxicity and a substantial proportion of patients remain refractory to treatment. A more comprehensive understanding of the complexity of SLE immunopathogenesis has evolved over the past decade and has led to the testing of several biologic agents in clinical trials. There is a clear need for new therapeutic agents that overcome these issues, and biologic agents offer exciting prospects as future SLE therapies.An array of promising new therapies are currently emerging or are under development including B-cell depletion therapies, agents targeting B-cell survival factors, blockade of T-cell co-stimulation and anti-cytokine therapies, such as monoclonal antibodies against interleukin-6 and interferon-α.

Dacryoadenitis and diffuse orbital inflammation: unusual first presentations of Churg-Strauss syndrome.

Churg-Strauss syndrome (CSS) is a rare form of vasculitis involving small-to medium-sized blood vessels. CSS typically affects blood vessels of the lungs, gastrointestinal system, and peripheral nerves, but can also involve the heart, skin and kidneys. Here we present two CSS patients presenting with unusual ocular manifestations. Although ophthalmic complications remain relatively uncommon in vasculitides such as Churg-Strauss syndrome, these conditions should be considered in patients presenting with ocular manifestations and concurrent ear, nose and throat symptoms, arthralgia or with positive ANCA and eosinophilia.

Comparative effects of antiresorptive agents on bone mineral density and bone turnover in postmenopausal women.

Postmenopausal osteoporosis is a common clinical entity; its complications represent a significant burden to society. In recent years the choice of therapies available for the treatment of postmenopausal osteoporosis has increased dramatically. There are a number of antiresorptive agents currently available including hormone replacement therapy (HRT), selective estrogen receptor modulators (SERMs), bisphosphonates, and dual action bone agents. It is difficult to truly compare these therapies given the lack of direct head-to head studies. The efficacy of antiresorptive therapies can be assessed in a number of ways including measurement of bone mineral density (BMD), assessment of bone turnover markers, and fracture reduction. Other important factors include ease of administration and consequent patient compliance. This article reviews the currently available antiresorptive agents and their effects on the above outcome measures.