Immune checkpoint inhibitor-related myositis and myocarditis in patients with cancer

Mediation of macrophage M1 polarization dynamics change by ubiquitin-autophagy-pathway regulated NLRP3 inflammasomes in PD-1 inhibitor-related myocardial inflammatory injury

OBJECTIVE AND DESIGN

Immune checkpoint inhibitors (ICIs)-induced cardiac injury is a life-threatening immune-related adverse events (irAEs). However, the current understanding of its pathogenesis and therapeutic options is relatively limited. We aimed to provide a comprehensive overview of the myocardial inflammatory injury process and underlying mechanisms associated with ICIs.

MATERIAL OR SUBJECTS

We conducted a descriptive analysis of lung cancer patients with ICIs-induced myocarditis at our institution and validated our clinical findings using single-cell sequencing (scRNA-seq) data. Furthermore, we established animal and cellular models to investigate the underlying mechanisms.

RESULTS

Our findings revealed that lung cancer patients with ICIs-induced myocarditis exhibit an early increase in peripheral blood monocytes, which migrate to the heart and differentiate into macrophages, ultimately leading to myocardial inflammation. Mechanistically, programmed death-1 (PD-1) inhibition triggers myocardial inflammation through the activation of the signal transducer and activator of transcription 1 (STAT1)/nuclear factor kappa-B (NF-κB)/oligomerization domain (NOD)-like receptor thermal protein domain-associated protein 3 (NLRP3) signaling pathway and drives the polarization of macrophages towards the M1 phenotype. However, the ubiquitin (Ub)-autophagy pathway degrades NLRP3 inflammasomes, resulting in the gradual resolution of inflammation and the transition of M1 macrophages to the M2 phenotype. Finally, mouse experiments confirmed that NLRP3 inhibition using MCC950 effectively alleviates myocardial inflammatory injury.

CONCLUSIONS

We recommend monitoring fluctuations in peripheral blood monocyte counts in lung cancer patients undergoing ICIs treatment. Additionally, MCC950 holds potential as a therapeutic agent for ICIs-induced cardiac inflammation injury.

Durable Left Ventricular Assist Device Outflow Graft Obstructions: Clinical Characteristics and Outcomes

PURPOSE

We report on the clinical course and management of patients supported with durable implantable LVADs who developed outflow graft obstructions at a large academic center.

METHODS

We performed a retrospective review of patients receiving LVAD support from 2012 through 2020. Patients who developed an outflow graft obstruction diagnosed by computed tomography angiography (CTA) or angiogram were identified, and patient characteristics and outcomes were reported.

RESULTS

Of the 324 patients supported by LVAD at our institution, 11 patients (3.4%) were diagnosed with outflow graft obstructions. The most common presentation was low flow alarms, which was present in 10/11 patients, and the remaining patient presented with lightheadedness. Patients had minimal LDH elevation with 8/11 presenting with less than 2-fold the upper limit of normal. Transthoracic echocardiograms were not diagnostic, but CTA enabled non-invasive diagnoses in 8/11 of the patients. Three patients with extrinsic compression of the outflow graft successfully underwent endovascular stent placement, and three patients with outflow cannula kinks received supportive care. Of the five patients diagnosed with intraluminal thromboses, one received a heart transplant, one underwent an outflow graft revision, and three received supportive care due to comorbidities.

CONCLUSION

Outflow graft obstructions remain a rare, but serious complication. The true prevalence of this entity is likely underestimated due to the non-specific clinical presentation. CTA is a pivotal non-invasive diagnostic step. Patients with external compression were successfully treated with endovascular stenting.

Myositis with prominent B-cell aggregates causing shrinking lung syndrome in systemic lupus erythematosus: a case report

BACKGROUND

Shrinking lung syndrome (SLS) is a rare manifestation of systemic lupus erythematosus (SLE) characterized by decreased lung volumes and diaphragmatic weakness in a dyspneic patient. Chest wall dysfunction secondary to pleuritis is the most commonly proposed cause. In this case report, we highlight a new potential mechanism of SLS in SLE, namely diaphragmatic weakness associated with myositis with CD20 positive B-cell aggregates.

CASE PRESENTATION

A 51-year-old Caucasian woman was diagnosed with SLE and secondary Sjögren's syndrome based on a history of pleuritis, constrictive pericarditis, polyarthritis, photosensitivity, alopecia, oral ulcers, xerophthalmia and xerostomia. Serologies were significant for positive antinuclear antibodies, anti-SSA, lupus anticoagulant and anti-cardiolopin. Blood work revealed a low C3 and C4, lymphopenia and thrombocytopenia. She was treated with with low-dose prednisone and remained in remission with oral hydroxychloroquine. Seven years later, she developed mild proximal muscle weakness and exertional dyspnea. Pulmonary function testing revealed a restrictive pattern with small lung volumes. Pulmonary imaging showed elevation of the right hemidiaphragm without evidence of interstitial lung disease. Diaphragmatic ultrasound was suggestive of profound diaphragmatic weakness and dysfunction. Based on these findings, a diagnosis of SLS was made. Her proximal muscle weakness was investigated, and creatine kinase (CK) levels were normal. Electromyography revealed fibrillation potentials in the biceps, iliopsoas, cervical and thoracic paraspinal muscles, and complex repetitive discharges in cervical paraspinal muscles. Biceps muscle biopsy revealed dense endomysial lymphocytic aggregates rich in CD20 positive B cells, perimysial fragmentation with plasma cell-rich perivascular infiltrates, diffuse sarcolemmal upregulation of class I MHC, perifascicular upregulation of class II MHC, and focal sarcolemmal deposition of C5b-9. Treatment with prednisone 15 mg/day and oral mycophenolate mofetil 2 g/day was initiated. Shortness of breath and proximal muscle weakness improved significantly.

CONCLUSION

Diaphragmatic weakness was the inaugural manifestation of myositis in this patient with SLE. The spectrum of myologic manifestations of myositis with prominent CD20 positive B-cell aggregates in SLE now includes normal CK levels and diaphragmatic involvement, in association with SLS.

Steroid-refractory dermatologic and pulmonary toxicity in a patient on rituximab treated with pembrolizumab for progressive urothelial carcinoma: a case report

BACKGROUND

Increasingly widespread use of programmed cell death protein 1 (PD-1) immune checkpoint inhibitors (ICIs) for treatment of a variety of progressive malignancies continues to reveal a range of immune-related adverse events (irAEs), necessitating immunosuppressive therapy for management. While a single course of systemic corticosteroids may be sufficient for many irAEs, no clear standard-of-care guidelines exist for steroid-refractory cases. We present an unusual case of a patient who developed several steroid-refractory novel irAEs on pembrolizumab despite ongoing B cell-directed immunosuppressive therapy with rituximab, who ultimately noted resolution of symptoms with tacrolimus, a T-cell-directed immunosuppressant.

CASE PRESENTATION

This 72-year-old Caucasian man with Waldenstrom's macroglobulinemia and myelin-associated glycoprotein (MAG) immunoglobulin M (IgM) antibody-associated neuropathy was being treated with maintenance rituximab and intravenous immunoglobulin when he was started on pembrolizumab (2.26 mg/kg) for metastatic urothelial cancer 31 months after surgery and adjuvant chemotherapy. After his third dose of pembrolizumab, he developed a painful blistering papular rash of the distal extremities. He received two more doses of pembrolizumab before he also developed diarrhea, and it was held; he was initiated on 1 mg/kg prednisone for presumed ICI-induced dermatitis and colitis. Skin biopsy 10 weeks after cessation of pembrolizumab and taper of steroids to 20  mg daily revealed a unique bullous erythema multiforme. He was then admitted with dyspnea and imaging concerning for necrotizing pneumonia, but did not respond to antibiotic therapy. Bronchoscopy and biopsy revealed acute fibrinous organizing pneumonia. His symptoms failed to fully respond to multiple courses of high-dose systemic corticosteroids and a trial of azathioprine, but pneumonia, diarrhea, and skin rash all improved markedly with tacrolimus. The patient has since completed his therapy for tacrolimus, continues off of ICI, and has not experienced a recurrence of any irAEs, though has more recently experienced progression of his cancer.

CONCLUSION

Despite immunosuppression with rituximab and intravenous immunoglobulin, two immunomodulators targeting B cells, ICI cessation, and systemic corticosteroid therapy, our patient developed two high-grade unusual irAEs, bullous erythema multiforme and acute fibrinous organizing pneumonia. Our patient's improvement with tacrolimus can offer critical insight into the pathophysiology of steroid-refractory irAEs.

Diagnosis and Treatment of Rheumatic Adverse Events Related to Immune Checkpoint Inhibitors

Immune checkpoint inhibitors (ICIs) have completely changed the treatment of cancer, and they also can cause multiple organ immune-related adverse reactions (irAEs). Among them, rheumatic irAE is less common, mainly including inflammatory arthritis, rheumatic myalgia/giant cell arteritis, inflammatory myopathy, and Sjogren's syndrome. For oncologists, rheumatism is a relatively new field, and early diagnosis and treatment is very important, and we need to work closely with experienced rheumatologists. In this review, we focused on the incidence, clinical characteristics, and treatment strategies of rheumatic irAE.