Rising Prevalence of Mild Chronic Gastritis in Children: A Single Center Experience.

OBJECTIVES AND METHODS: We analyzed upper endoscopic and histological findings in 3 cohorts of children undergoing upper gastrointestinal endoscopy over a 10-year period. Five hundred seventy-nine patients were identified, with 244 (42%), 199 (35%), and 136 (23%) in the 2011, 2015, and 2019 cohorts, respectively. The most common symptoms and signs were abdominal pain, vomiting, failure to thrive, and diarrhea. RESULTS: The number of patients who had histological evidence of chronic gastritis increased from 2011 (n = 70, 29%) to 2015 (n = 106, 53%) and 2019 (n = 92, 68%; P < .001). The prevalence of "normal" endoscopic gastric findings was higher in controls (n = 247, 90%) compared to cases (n = 201, 76%; P < .001). There was a small but statistically significant difference in endoscopic esophageal grading (P = .008) over time, with lower grades being more prevalent in 2011 compared to 2015 (P = .026) and 2019 (P = .001). Crude comparisons of the predictors (sex, weight percentile, payor type, month of endoscopy, symptom duration, PPI exposure, and endoscopic stomach findings) yielded no difference between cases and controls. CONCLUSIONS: There has been a significant rise in the prevalence of mild chronic gastritis or non-specific gastritis over the last decade in our population.

ALK-Rearranged Epithelioid Mesenchymal Neoplasm: Expanding the Spectrum of Tyrosine Kinase-Altered Mesenchymal Tumors.

The anaplastic lymphoma kinase (ALK) gene encodes a receptor tyrosine kinase, and fusions involving this gene have been reported in a variety of mesenchymal neoplasms. ALK-altered tumors with epithelioid morphology have been described in epithelioid inflammatory myofibroblastic sarcoma and epithelioid fibrous histiocytoma. Herein, we describe the clinicopathologic features of 7 ALK-rearranged mesenchymal tumors with epithelioid morphology occurring predominately in the pediatric population. Tumors occurred in 4 females and 3 males with an age ranging from 1 month to 28 years. Five tumors were superficial and solitary, while 1 presented with multiple peritoneal/omental nodules, and 1 presented as a large mediastinal mass. Morphologically, all tumors comprised epithelioid cells arranged in sheets, anastomosing cords, or small clusters embedded in a myxohyaline stroma. The cells had slightly variably sized ovoid nuclei with moderately prominent nucleoli and abundant eosinophilic cytoplasm. Four cases had sparse mitotic figures without necrosis. The remaining 3 tumors (2 deep and 1 superficial) had more than 10 mitoses per 10 high-power fields as well as foci of necrosis. ALK fusions were identified in all cases. The fusion partners included HMBOX1 (n = 1), VCL (n = 1), PRRC2B (n = 1), MYH10 (n = 1), STRN (n = 1), and EML4 (n = 2). One tumor recurred locally 2 years after initial resection; 1 patient had widely metastatic disease (mediastinal tumor). At the time of last follow-up (n = 6), 4 patients were alive without evidence of disease, 1 died due to complications of therapy (peritoneal tumor), and 1 was alive with disease. Our findings expand the spectrum of ALK-rearranged mesenchymal tumors. Our cases predominately occurred in older children and mainly exhibited epithelioid to round cell morphology, as opposed to spindle cell morphology. We also show that tumors in a deep location with higher-grade features follow a more aggressive clinical course.

Case Report: Immune checkpoint inhibitor-induced multiorgan vasculitis successfully treated with rituximab.

Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of cancer. ICIs have a unique side effect profile, generally caused by inflammatory tissue damage, with clinical features similar to autoimmune conditions. Acute kidney injury from ICIs has been well studied; incidence ranges from 1% to 5%, with higher incidence when combination ICI therapies are used. Although the overall reported incidence of ICI-associated glomerulonephritis is less than 1%, vasculitis is the most commonly reported ICI-related glomerulonephritis. Other biopsy findings include thrombotic microangiopathy, focal segmental glomerulosclerosis, minimal change disease, and IgA nephropathy with secondary amyloidosis. We report a case in which a woman previously treated with the PD-L1 inhibitor durvalumab for locally advanced non-small cell lung cancer with pre-existing antineutrophil cytoplasmic (anti-PR3) antibody who later developed multi-organ vasculitis after ICI exposure, which was successfully treated with rituximab, with continued cancer remission for 3 years.

Plasma Biomarkers and Fractional Exhaled Nitric Oxide in the Diagnosis of Eosinophilic Esophagitis.

OBJECTIVES: Eosinophilic esophagitis (EoE) is a chronic disease which requires endoscopy with biopsies for diagnosis and monitoring. We aimed to identify a panel of non-invasive markers that could help identify patients with active EoE. METHODS: In this prospective cohort study, we enrolled 128 children aged 5-18 years old, scheduled for endoscopy for suspected esophageal or peptic disease. On the day of the endoscopy, fractionated exhaled nitric oxide (FeNO) was measured; and blood was collected for peripheral absolute eosinophil count (AEC), plasma amino acids, and plasma polyamine analysis. Patients were grouped into controls (n = 91), EoE in remission (n = 16), or active EoE (n = 21), based on esophageal eosinophilia and history of EoE. RESULTS: AEC was not statistically significant different among the groups compared ( P = 0.056). Plasma amino acids: citrulline (CIT), ß-alanine (ß-ALA), and cysteine (CYS) were higher in active EoE compared to controls ( P < 0.05). The polyamine spermine was lower in active EoE versus controls ( P < 0.05). Receiver operator characteristic (ROC) curve to assess the predictive capability of a combined score made of FeNO, ß-ALA, CYS, and spermine had an area under curve (AUC) of 0.90 (95% CI: 0.80-0.96) in differentiating active EoE from controls and 0.87 (95% CI: 0.74-1.00) when differentiating active EoE from EoE in remission. CONCLUSION: A panel comprising FeNO, 2 plasma amino acids (ß-ALA, CYS) and the polyamine spermine can be used as a non-invasive tool to differentiate active EoE patients from controls.

Tertiary lymphoid structure signatures are associated with immune checkpoint inhibitor related acute interstitial nephritis.

Tertiary lymphoid structures (TLSs) are associated with anti-tumor response following immune checkpoint inhibitor (ICI) therapy, but a commensurate observation of TLS is absent for immune related adverse events (irAEs) i.e. acute interstitial nephritis (AIN). We hypothesized that TLS-associated inflammatory gene signatures are present in AIN and performed NanoString-based gene expression and multiplex 12-chemokine profiling on paired kidney tissue, urine and plasma specimens of 36 participants who developed acute kidney injury (AKI) on ICI therapy: AIN (18), acute tubular necrosis (9), or HTN nephrosclerosis (9). Increased T and B cell scores, a Th1-CD8+ T cell axis accompanied by interferon-g and TNF superfamily signatures were detected in the ICI-AIN group. TLS signatures were significantly increased in AIN cases and supported by histopathological identification. Furthermore, urinary TLS signature scores correlated with ICI-AIN diagnosis but not paired plasma. Urinary CXCL9 correlated best to tissue CXCL9 expression (rho 0.75, p < 0.001) and the ability to discriminate AIN vs. non-AIN (AUC 0.781, p-value 0.003). For the first time, we report the presence of TLS signatures in irAEs, define distinctive immune signatures, identify chemokine markers distinguishing ICI-AIN from common AKI etiologies and demonstrate that urine chemokine markers may be used as a surrogate for ICI-AIN diagnoses.

Pathologic Predictors of Response to Treatment of Immune Checkpoint Inhibitor-Induced Kidney Injury.

BACKGROUND: Immune-related adverse events are a management challenge in patients receiving immune checkpoint inhibitors (ICIs). The most common renal immune-related adverse event, acute interstitial nephritis (AIN), is associated with patient morbidity and mortality. AIN, characterized by infiltration of renal tissue with immune cells, may be analogous to kidney transplant rejection. We evaluated clinical variables and pathologic findings to identify predictors of renal response and overall survival (OS) in patients with ICI-induced AIN. DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS: We reviewed the records and biopsy specimens of all 35 patients treated for ICI-induced AIN at our institution, between August 2007 and August 2020, who had biopsy specimens available. Two board-certified renal pathologists graded the severity of inflammation and chronicity using transplant rejection Banff criteria and performed immunohistochemistry analysis. Patients were categorized as renal responders if creatinine had any improvement or returned to baseline within 3 months of initiating treatment for AIN. Clinical and pathologic characteristics and OS were compared between responders and non-responders. RESULTS: Patients with high levels of interstitial fibrosis were less likely to be responders than those with less fibrosis (p = 0.02). Inflammation, tubulitis, the number of eosinophils and neutrophils, and the clustering or presence of CD8+, CD4+, CD20+, or CD68+ cells were not associated with renal response. Responders had better OS than non-responders (12-month OS rate 77% compared with 27%, p = 0.025). Responders who received concurrent ICIs had the best OS, and non-responders who did not receive concurrent ICIs had the worst OS (12-month OS rate 100% for renal response and concurrent ICIs, 72% for renal response and no concurrent ICIs, and 27% for no renal response and no concurrent ICIs; p = 0.041). CONCLUSIONS: This is the first analysis of ICI induced nephritis where a detailed pathological and clinical evaluation was performed to predict renal response. Low levels of interstitial fibrosis in kidney tissue are associated with renal response to treatment for ICI-induced AIN, and the renal response and use of concurrent ICIs are associated with better OS in these patients. Our findings highlight the importance of the early diagnosis and treatment of ICI-AIN, while continuing concurrent ICI therapy.

Urinary T cells are detected in patients with immune checkpoint inhibitor-associated immune nephritis that are clonotypically identical to kidney T cell infiltrates.

Acute kidney injury (AKI) occurs in ~20% of patients receiving immune checkpoint inhibitor (ICI) therapy; however, only 2-5% will develop ICI-mediated immune nephritis. Conventional tests are nonspecific in diagnosing disease pathology and invasive procedures (i.e. kidney biopsy) may not be feasible. In other autoimmune renal diseases, urinary immune cells correlated with the pathology or were predictive of disease activity. Corresponding evidence and analysis are absent for ICI-mediated immune nephritis. We report the first investigation analyzing immune cell profiles of matched kidney biopsies and urine of patients with ICI-AKI. We demonstrated the presence of urinary T cells in patients with immune nephritis by flow cytometry analysis. Clonotype analysis of T cell receptor (TCR) sequences confirmed enrichment of kidney TCRs in urine. As ICI therapies become standard of care for more cancers, noninvasively assessing urinary immune cells of ICI therapy recipients can facilitate clinical management and an opportunity to tailor ICI-nephritis treatment.

Case Report: Successful treatment of late-onset immune checkpoint inhibitor-associated membranous nephropathy in a patient with advanced renal cell carcinoma.

Background: Diagnosing immune checkpoint inhibitor (ICI)-associated nephritis can be challenging since it is a rare complication of therapy, associated with a spectrum of immune-mediated pathologies, and can present months after ICI therapy discontinuation (i.e., late-onset). ICIs are increasingly administered in combination with other cancer therapies with associated nephrotoxicity, further obfuscating the diagnosis of ICI-associated nephritis. In this report, we describe the first suspected case of late-onset ICI-associated membranous nephropathy (MN) in a patient with metastatic clear cell renal cell carcinoma (RCC) who had discontinued ICI therapy 6 months prior to presentation. Prompt recognition of the suspected late-onset immune-related adverse event (irAE) resulted in the successful treatment of MN and continuation of RCC therapy. Case presentation: A 57-year-old man with metastatic clear cell RCC was responsive to third-line RCC therapy with lenvatinib (oral TKI) and everolimus (oral mTOR inhibitor) when he presented with nephrotic range proteinuria and acute kidney injury (AKI). His kidney biopsy revealed probable secondary MN with subendothelial and mesangial immune complex deposits and negative staining for both phospholipase A2 receptor (PLA2R) and thrombospondin type-1 domain-containing 7A (THSD7A). While a diagnosis of paraneoplastic MN could not be excluded, the patient was responding to cancer therapy and had tumor regression. However, 6 months prior to presentation, the patient had received pembrolizumab, an ICI, with his first-line RCC treatment. Due to concern that the patient may be presenting with late-onset ICI-associated MN, he was effectively treated with rituximab, which allowed for his continued RCC therapy. Conclusion: This report highlights the first case of suspected late-onset ICI-associated MN and the increasing complexity of recognizing renal irAEs. With the growing indications for the use of ICIs in combination with other cancer therapies, recognizing the various presentations of ICI-immune nephritis can help guide patient management and treatment.

Influenza-induced thrombotic microangiopathy in a patient with cancer on proteasome inhibitor: a diagnostic dilemma.

Thrombotic microangiopathy (TMA) in a cancer patient is a common complication of either cancer itself or anticancer therapy. Incidence of TMA from anticancer therapy was found to be > 15%, since the introduction of anti-angiogenic drugs like anti-vascular endothelial growth factor agents. It is, however, important to not ignore other causes of TMA such as bacteria, viruses, antiplatelet drugs, hereditary complement mutations, and autoimmune disorders. We present such a diagnostic dilemma in our patient who was admitted with influenza and was found to have TMA on renal biopsy, while on proteasome inhibitor (PI) therapy. With this case, we would like to highlight the importance of understanding the true cause of TMA to avoid unwarranted long-term discontinuation of life saving anti-cancer drugs after TMA resolution.

Onconephrology and Thrombotic Microangiopathy: Looking Beyond the Horizon.

Thrombotic microangiopathies (TMAs) represent a complex interaction of endothelial and podocyte biology, nephron physiology, complement genetics, and oncologic therapies with host immunology. The complexity of various factors, such as molecular causes, genetic expressions, and immune system mimicking, along with incomplete penetrance, make it difficult to find a straightforward solution. As a result, there may be variations in diagnosis, study, and treatment approaches, and achieving a consensus can be challenging. Here, we review the molecular biology, pharmacology, immunology, molecular genetics, and pathology of the various TMA syndromes in the setting of cancer. Controversies in etiology, nomenclature, and points requiring further clinical, translational, and bench research are discussed. Complement-mediated TMAs, chemotherapy drug-mediated TMAs, TMAs in monoclonal gammopathy, and other TMAs central to onconephrology practice are reviewed in detail. In addition, established and emerging therapies within the US Food and Drug Administration pipeline subsequently are discussed. Finally, a comprehensive review of critical areas of onconephrology clinical practice is presented as practical value to the clinical practitioner and seeds of investigation to be sown among the community of atypical hemolytic uremic syndrome researchers.

Lupus-Like Glomerulonephritis Associated With Regorafenib, a Multikinase Inhibitor.

Drug-induced lupus glomerular diseases have historically been associated with hydralazine, but new drugs that modify the growth, metabolism, and immunity of cells are increasingly found to cause glomerular disease. This includes anti-tumor necrotic factor and other antibody agents used in cancer treatment. Multitarget tyrosine kinases such as regorafenib are increasingly used in metastatic malignancies with good outcomes. Currently, they are not known to have kidney complications except for proteinuria, hypertension, and electrolyte disturbances such as hypophosphatemia. We report a patient who presented within months after starting regorafenib therapy for metastatic colon cancer with acute kidney injury, proteinuria, and hematuria. Biopsy revealed endocapillary proliferative glomerulonephritis with full-house staining on immunofluorescence in the absence of any systemic manifestation of systemic lupus erythematosus. The kidney injury improved with corticosteroid treatment and discontinuation of regorafenib therapy. We discuss the possible mechanisms that led to this class IV pattern of lupus nephritis and conclude that it is likely drug-induced lupus nephritis from regorafenib.

Infliximab for the treatment of patients with checkpoint inhibitor-associated acute tubular interstitial nephritis.

Acute tubular interstitial nephritis (ATIN) is the most frequently reported pathology in patients with checkpoint inhibitor (CPI) induced acute kidney injury (AKI). Glucocorticoid (GC) therapy and discontinuation of CPI are the mainstay of treatment to prevent permanent renal dysfunction and dialysis. However, less than 50% of patients have complete kidney recovery and relapse of ATIN can occur. Infliximab is effective in treating other immune-related adverse events but its use for the treatment of CPI-ATIN is not well established. We report the first retrospective study examining the steroid-sparing potential of infliximab in achieving durable and complete renal recovery for patients with CPI-ATIN. Data were collected from medical records of patients diagnosed with CPI-AKI with a kidney biopsy or clinical diagnosis of ATIN that was managed with GC and infliximab. Infliximab-containing regimens were used to treat 10 patients with CPI-ATIN. Four patients relapsing after GC therapy achieved durable and complete renal recovery, four patients experienced partial renal recovery, and two patients showed no improvement in kidney function. This is the first study evaluating clinical outcomes using an infliximab-containing regimen for treatment of relapsed CPI-ATIN in patients or patients failing to achieve complete response after primary therapy. Our data suggest that infliximab may be a treatment option for achieving durable and complete renal recovery in this patient population and represents a potential steroid-sparing strategy in challenging cases of CPI-ATIN. Rigorous clinical studies are warranted to evaluate the risk-benefit analysis for infliximab usage in CPI-ATIN patients.

Checkpoint inhibitor-related renal vasculitis and use of rituximab.

The percentage of patients with cancer eligible for checkpoint inhibitor (CPI) therapy has increased rapidly over the past few years and approaches 45%. As a result, more cases of CPI-related nephrotoxicity, including a rare subset with vasculitis, are being reported. To elucidate the clinical presentation of CPI-associated renal vasculitis and its possible mechanisms, treatment options and prognosis, we describe cases from a comprehensive cancer center and reviewed the literature for similar cases. We retrospectively reviewed the charts of all patients with cancer from 2014 to 2020 who were diagnosed with CPI-related nephrotoxicity and underwent a kidney biopsy. We identified five cases of renal vasculitis: three patients were diagnosed with seronegative antineutrophil cytoplasm antibody (ANCA)-associated vasculitis, one case with seropositive ANCA-associated vasculitis and one case was diagnosed with IgA vasculitis. Of these cases, four patients were receiving nivolumab, and one patient was receiving tremelimumab. All patients had microscopic hematuria, four out of five patients had negative ANCA serology, one patient had concurrent lung involvement and positive ANCA serology, and all had severe acute kidney injury with creatinine >4.50 mg/dL on diagnosis. All patients were treated by discontinuing CPI and initiating corticosteroids and rituximab. Three patients received plasmapheresis; two of these required renal replacement therapy including the patient with lung involvement. All patients after rituximab had a partial or complete renal response. Two patients died within 8 months of diagnosis due to malignancy progression. None of the patients had a relapse of vasculitis. We demonstrated that CPI can be associated with different types of renal vasculitis that are predominantly ANCA negative and manifest as severe acute kidney injury. Despite the lack of strong evidence, treatment similar to treatment of primary seropositive ANCA-associated vasculitis with corticosteroids and rituximab is well tolerated with favorable renal outcomes.

Eosinophilic granulomatosis with polyangiitis in a continuous flow left ventricular assist device patient: a case report and review of literature.

Eosinophilic granulomatosis with polyangiitis (EGPA), also known as Churg-Strauss syndrome (CSS), is a rare autoimmune disease with an estimated incidence of approximately 0.11 to 2.66 new cases per 1 million people per year and an overall prevalence of 10.7 to 14 per 1 million adults [1]. No gender predominance or ethnic predisposition has clearly been demonstrated in CSS [1]. Most of the patients are misdiagnosed over a period of time prior to being correctly classified with the disease. Here, we report the complex case of a 64-year-old African American man with advanced heart failure who received a left ventricular assist device (LVAD) and was subsequently diagnosed with EGPA. EGPA is a clinical syndrome that is associated with sequelae that can negatively add to the morbidity associated with LVAD placement.

Nephrotoxicity of immune checkpoint inhibitors beyond tubulointerstitial nephritis: single-center experience.

RATIONALE & OBJECTIVE: The approved therapeutic indication for immune checkpoint inhibitors (CPIs) are rapidly expanding including treatment in the adjuvant setting, the immune related toxicities associated with CPI can limit the efficacy of these agents. The literature on the nephrotoxicity of CPI is limited. Here, we present cases of biopsy proven acute tubulointerstitial nephritis (ATIN) and glomerulonephritis (GN) induced by CPIs and discuss potential mechanisms of these adverse effects. STUDY DESIGN, SETTING, & PARTICIPANTS: We retrospectively reviewed all cancer patients from 2008 to 2018 who were treated with a CPI and subsequently underwent a kidney biopsy at The University of Texas MD Anderson Cancer Center. RESULTS: We identified 16 cases diagnosed with advanced solid or hematologic malignancy; 12 patients were male, and the median age was 64 (range 38 to 77 years). The median time to developing acute kidney injury (AKI) from starting CPIs was 14 weeks (range 6-56 weeks). The average time from AKI diagnosis to obtaining renal biopsy was 16 days (range from 1 to 46 days). Fifteen cases occurred post anti-PD-1based therapy. ATIN was the most common pathologic finding on biopsy (14 of 16) and presented in almost all cases as either the major microscopic finding or as a mild form of interstitial inflammation in association with other glomerular pathologies (pauci-immune glomerulonephritis, membranous glomerulonephritis, C3 glomerulonephritis, immunoglobulin A (IgA) nephropathy, or amyloid A (AA) amyloidosis). CPIs were discontinued in 15 out of 16 cases. Steroids and further immunosuppression were used in most cases as indicated for treatment of ATIN and glomerulonephritis (14 of 16), with the majority achieving complete to partial renal recovery. CONCLUSIONS: Our data demonstrate that CPI related AKI occurs relatively late after CPI therapy. Our biopsy data demonstrate that ATIN is the most common pathological finding; however it can frequently co-occur with other glomerular pathologies, which may require immune suppressive therapy beyond corticosteroids. In the lack of predictive blood or urine biomarker, we recommend obtaining kidney biopsy for CPI related AKI.

PTEN hamartoma of the soft tissue: the initial manifestation of an underlying PTEN hamartoma tumor syndrome in a 4-year-old female.

A 4-year-old female was referred to pediatric orthopedic surgery for left leg pain and limping for 3 months following a motor vehicle collision. Recently, the patient's mother had noted left knee swelling and dragging of the left leg when walking. Past medical history was significant for hip dysplasia with slight leg length discrepancy. The patient was otherwise healthy. Physical examination was remarkable for left pre-patellar soft tissue fullness with normal range of motion. There was no warmth or tenderness. Subsequent ultrasound revealed a heterogeneous soft tissue mass superior and medial to the patella with a moderate degree of internal vascularity. MR exhibited a heterogeneous soft tissue mass with heterogeneous signal on both T1- and T2-weighted images centered within the vastus medialis obliquus muscle infiltrating the quadriceps tendon. Excisional biopsy was performed with a histopathologic diagnosis of fibroadipose tissue with anomalous vessels, suggestive of phosphatase and tensin homolog (PTEN) hamartoma of the soft tissue (PHOST). The patient was found to be positive for the PTEN gene mutation on genetic testing. The child was also determined to be macrocephalic, a major criterion for PTEN hamartoma tumor syndrome (PHTS). The geneticist advised the patient to undergo yearly physical examinations and early, routine surveillance for several malignancies occurring with PHTS. This case report presents the ultrasound and MRI appearance of a rare benign tumor typically appearing in pediatric patients. The strong association between PHOST and other soft tissue malignancies and the resulting need for life-long surveillance make PHOST an important pathology to recognize.