Natural history study of patients with familial platelet disorder with associated myeloid malignancy.

ABSTRACT: Deleterious germ line RUNX1 variants cause the autosomal dominant familial platelet disorder with associated myeloid malignancy (FPDMM), characterized by thrombocytopenia, platelet dysfunction, and a predisposition to hematologic malignancies (HMs). We launched a FPDMM natural history study and, from January 2019 to December 2021, enrolled 214 participants, including 111 patients with 39 different RUNX1 variants from 45 unrelated families. Seventy of 77 patients had thrombocytopenia, 18 of 18 had abnormal platelet aggregometry, 16 of 35 had decreased platelet dense granules, and 28 of 55 had abnormal bleeding scores. Nonmalignant bone marrows showed increased numbers of megakaryocytes in 12 of 55 patients, dysmegakaryopoiesis in 42 of 55, and reduced cellularity for age in 30 of 55 adult and 17 of 21 pediatric cases. Of 111 patients, 19 were diagnosed with HMs, including myelodysplastic syndrome, acute myeloid leukemia, chronic myelomonocytic leukemia, acute lymphoblastic leukemia, and smoldering myeloma. Of those 19, 18 were relapsed or refractory to upfront therapy and referred for stem cell transplantation. In addition, 28 of 45 families had at least 1 member with HM. Moreover, 42 of 45 patients had allergic symptoms, and 24 of 30 had gastrointestinal (GI) symptoms. Our results highlight the importance of a multidisciplinary approach, early malignancy detection, and wider awareness of inherited disorders. This actively accruing, longitudinal study will genotype and phenotype more patients with FPDMM, which may lead to a better understanding of the disease pathogenesis and clinical course, which may then inform preventive and therapeutic interventions. This trial was registered at www.clinicaltrials.gov as #NCT03854318.

Granulomatous inflammation in inborn errors of immunity.

Granulomas have been defined as inflammatory infiltrates formed by recruitment of macrophages and T cells. The three-dimensional spherical structure typically consists of a central core of tissue resident macrophages which may merge into multinucleated giant cells surrounded by T cells at the periphery. Granulomas may be triggered by infectious and non-infectious antigens. Cutaneous and visceral granulomas are common in inborn errors of immunity (IEI), particularly among patients with chronic granulomatous disease (CGD), combined immunodeficiency (CID), and common variable immunodeficiency (CVID). The estimated prevalence of granulomas in IEI ranges from 1%-4%. Infectious agents causing granulomas such Mycobacteria and Coccidioides presenting atypically may be 'sentinel' presentations for possible underlying immunodeficiency. Deep sequencing of granulomas in IEI has revealed non-classical antigens such as wild-type and RA27/3 vaccine-strain Rubella virus. Granulomas in IEI are associated with significant morbidity and mortality. The heterogeneity of granuloma presentation in IEI presents challenges for mechanistic approaches to treatment. In this review, we discuss the main infectious triggers for granulomas in IEI and the major forms of IEI presenting with 'idiopathic' non-infectious granulomas. We also discuss models to study granulomatous inflammation and the impact of deep-sequencing technology while searching for infectious triggers of granulomatous inflammation. We summarize the overarching goals of management and highlight the therapeutic options reported for specific granuloma presentations in IEI.

Updates in diagnosis and management of paediatric mastocytosis.

PURPOSE OF REVIEW: Paediatric mastocytosis is a rare clonal disorder characterized by the overproduction and organ infiltration of mast cells. Symptoms are due to mast cell mediator release. Cutaneous mastocytosis is the most common presentation in children with systemic disease being rare. Our aim is to provide a practical guideline in differentiating subtypes of paediatric mastocytosis while providing actionable recommendations on diagnosis, clinical management, follow-up and prognosis. RECENT FINDINGS: Longitudinal cohort studies of paediatric cutaneous mastocytosis have shown spontaneous remission with favourable prognosis. Hereditary alpha-tryptasemia may coexist with mastocytosis; thus, screening for this disorder is recommended. There is an emerging role for serum tryptase in asthma endotyping and potential for using therapeutic tryptase inhibitors. SUMMARY: Morbidity in paediatric mastocytosis typically arises from symptoms secondary to mast cell mediator release. Prognosis for nonaggressive disease is typically favourable; however, risks for anaphylaxis and psychosocial morbidity may be underestimated. Symptomatic management and anticipatory guidance may help support patients and families throughout the disease course.

When to suspect inborn errors of immunity in Epstein-Barr virus-related lymphoproliferative disorders.

BACKGROUND: More than 95% of humans have been infected with Epstein-Barr virus (EBV) and develop anti-EBV IgG antibodies, conferring immunity. However, among specific populations, EBV may induce a range of B-cell lymphoproliferative disorders (LPDs). EBV may also contribute to T-cell and natural killer (NK)-cell lymphoproliferation. The immune system is essential to prevent infection and development of cancer. Inborn errors of immunity (IEIs) are a heterogenous group of more than 450 genetic disorders predisposing to severe and/or recurrent infection, autoimmunity, autoinflammation, or early-onset/severe neoplasia or lymphoproliferation. Monogenic disorders of T-cell and B-cell signalling are classic IEIs that predispose to EBV-associated LPDs. OBJECTIVES: We aimed to outline the various clinical manifestations of EBV-associated LPDs and the underlying IEIs associated with such presentations and discuss the recommended management and therapeutic options pertaining to these disorders. SOURCES: We searched PubMed, Embase, and Web of Science Core Collection on 30 September 2021. Clinical studies, systematic reviews, narrative reviews, and case reports were identified through search strategy and cross reference from primary literature. CONTENT: Effective T-cell and NK-cell cytotoxicity towards EBV-infected B cells relies on intact MAGT1-dependent NKG2D pathways and signalling lymphocyte activation molecular-associated protein-dependent signalling lymphocyte activation molecular receptors. The interaction between CD27 and CD70 is also critical to drive the expansion of EBV-specific T cells. IEIs due to T-cell and B-cell signalling defects and/or impaired T-cell and NK-cell cytotoxicity predispose to EBV-related lymphoproliferation. This includes classic disorders such as X-linked lymphoproliferative disease 1 (due to SH2D1A mutations), X-linked lymphoproliferative disease 2 (XIAP), and other genetic diseases, such as ITK, MAGT1, CD27, CD70, CTPS1, RASGRP1, and CORO1A deficiencies. EBV-driven lymphoproliferation may manifest to a lesser degree in MST1/STK4, DOCK8, STIM1, CORO1A, IL21R, PIK3CD gain-of-function, and PI3KR1 deficiencies. IMPLICATIONS: Early screening for IEIs is indicated in cases of EBV-related lymphoproliferation because different forms of IEIs have specific prognostic and therapeutic implications.

Interpretation of Dihydrorhodamine-1,2,3 Flow Cytometry in Chronic Granulomatous Disease: an Atypical Exemplar.

PURPOSE: This is a functional characterization of a novel CYBA variant associated with normal DHR flow cytometry. Chronic granulomatous disease (CGD) is an inborn error of immunity characterized by recurrent bacterial and fungal infections and dysregulated inflammatory responses due to defective phagocytic cell function leading to the formation of granulomas. CGD patients have pathogenic variants in any of the five components of the phagocytic NADPH oxidase, which transfers electrons through the phagosomal membrane and produces superoxide upon bacterial uptake. Here, we report a pediatric female patient with a novel homozygous missense variant (c.293C > T, p.(Ser98Leu)) in CYBA, encoding the p22phox protein, associated with autosomal recessive CGD. METHODS AND RESULTS: The patient presented with severe recurrent pneumonia. Specific pathogens identified included Burkholderia and Serratia species suggesting neutrophil functional abnormalities; however, the dihydrorhodamine-1,2,3 (DHR) flow cytometric and cytochrome c reduction assays for neutrophil respiratory burst fell within the low side of the normal range. Western blot and flow cytometric analysis of individual NADPH oxidase components revealed reduced levels of p22phox and gp91phoxphox proteins. The pathological consequence of the p.Ser98Leu variant was further evaluated in heterologous expression systems, which confirmed reduced p22phox protein stability and oxidase activity. CONCLUSIONS: Although this patient did not exhibit all the classic features of CGD, such as granulomas and skin infections, she had recurrent pneumonias with oxidant-sensitive pathognomonic organisms, resulting in appropriate targeted CGD testing. This case emphasizes the need to contextually interpret laboratory data, especially using clinical findings to direct additional assessments including genetic analysis.

Nodular regenerative hyperplasia in X-linked agammaglobulinemia: An underestimated and severe complication.

BACKGROUND: Late-onset complications in X-linked agammaglobulinemia (XLA) are increasingly recognized. Nodular regenerative hyperplasia (NRH) has been reported in primary immunodeficiency but data in XLA are limited. OBJECTIVES: This study sought to describe NRH prevalence, associated features, and impact in patients with XLA. METHODS: Medical records of all patients with XLA referred to the National Institutes of Health between October 1994 and June 2019 were reviewed. Liver biopsies were performed when clinically indicated. Patients were stratified into NRH+ or NRH- groups, according to their NRH biopsy status. Fisher exact test and Mann-Whitney test were used for statistical comparisons. RESULTS: Records of 21 patients with XLA were reviewed, with a cumulative follow-up of 129 patient-years. Eight patients underwent ≥1 liver biopsy of whom 6 (29% of the National Institutes of Health XLA cohort) were NRH+. The median age at NRH diagnosis was 20 years (range, 17-31). Among patients who had liver biopsies, alkaline phosphatase levels were only increased in patients who were NRH+ (P = .04). Persistently low platelet count (<100,000 per µL for >6 months), mildly to highly elevated hepatic venous pressure gradient and either hepatomegaly and/or splenomegaly were present in all patients who were NRH+. In opposition, persistently low platelet counts were not seen in patients who were NRH-, and hepatosplenomegaly was observed in only 1 patient who was NRH-. Hepatic venous pressure gradient was normal in the only patient tested who was NRH-. All-cause mortality was higher among patients who were NRH+ (5 of 6, 83%) than in the rest of the cohort (1 of 15, 7% among patients who were NRH- and who were classified as unknown; P = .002). CONCLUSIONS: NRH is an underreported, frequent, and severe complication in XLA, which is associated with increased morbidity and mortality.

Targeted pharmacologic immunomodulation for inborn errors of immunity.

Inborn errors of immunity consist of over 400 known single gene disorders that may manifest with infection susceptibility, autoimmunity, autoinflammation, hypersensitivity and cancer predisposition. Most patients are treated symptomatically with immunoglobulin replacement, prophylactic antimicrobials or broad immunosuppression pertaining to their disease phenotype. Other than haematopoietic stem cell transplantation, the aforementioned treatments do little to alter disease morbidity or mortality. Further, many patients may not be transplant candidates. In this review, we describe monogenic disorders affecting leucocyte migration, disorders of immune synapse formation and dysregulation of immune cell signal transduction. We highlight the use of off-label small molecules and biologics mechanistically targeted to altered disease pathophysiology of such diseases.

BTK inhibitors for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2): A Systematic Review.

ImportanceThe Bruton tyrosine kinase (BTK) regulates B cell and macrophage signaling, development, survival, and activation. BTK inhibition was shown to protect against lethal influenza-induced acute lung injury in mice. Inhibiting BTK has been hypothesized to ameliorate lung injury in patients with severe coronavirus disease 2019 (COVID-19). ObjectiveTo evaluate the use of BTK inhibitors (BTKinibs) during COVID-19 and assess how they may affect patient outcomes.Evidence ReviewWe searched PubMed, Embase, and Web of Science: Core on December 30, 2020. Clinical studies with at least 5 COVID-19 patients treated with BTKinibs were included. Case reports and reviews were excluded.FindingsOne hundred twenty-five articles were identified, 6 of which met inclusion criteria. Sample size ranged from 6 to 126 patients. Patient populations included subjects hospitalized with COVID-19 (6/6) and admitted to the intensive care unit (5/6). Patient age ranged between 35 and 98 years. Four studies included patients already receiving BTKinibs for their lymphoproliferative disease, 1 for Waldenstrom's macroglobulinemia and 3 for chronic lymphocytic leukemia (CLL). The most common clinical outcomes measured were oxygen requirements (4/6) and hospitalization rate or duration (3/6). Differences in standard-of-care reflected the date of study and pre-existing conditions in the various patient cohorts. Full-dose acalabrutinib was evaluated in 2 studies, one study evaluated full-dose ibrutinib, and another study evaluated both ibrutinib and acalabrutinib. The remainder 2 studies described outcomes in CLL patients on multiple BTKinibs and other CLL-targeted treatments. Three studies showed decreased oxygen requirements in patients who started or continued BTKinibs. All three studies that evaluated hospitalization rate or duration found favorable outcomes in those on BTKinibs. Conclusions and RelevanceBTKinib use was associated with decreased oxygen requirements and decreased hospitalization rates and duration. However, randomized clinical trials are needed to validate the beneficial effects of BTKinibs for acute SARS-CoV-2 infection.

Infectious Complications Predict Premature CD8+ T-cell Senescence in CD40 Ligand-Deficient Patients.

PURPOSE: CD40 ligand (CD40L)-deficient patients display increased susceptibilities to infections that can be mitigated with effective prophylactic strategies including immunoglobulin G (IgG) replacement and prophylactic antibiotics. CD8+ T-cell senescence has been described in CD40L deficiency, but it is unclear if this is an intrinsic feature of the disease or secondary to infectious exposures. To address this question, we assessed CD8+ T-cell senescence and its relationship to clinical histories, including prophylaxis adherence and infections, in CD40L-deficient patients. METHODS: Peripheral CD8+ T-cells from seven CD40L-deficient patients and healthy controls (HCs) were assessed for senescent features using T-cell receptor excision circle (TREC) analysis, flow cytometry, cytometry by time of flight (CyTOF) and in vitro functional determinations including CMV-specific proliferation and cytokine release assays. RESULTS: Three patients (5, 28, and 34 years old) who were poorly adherent to immunoglobulin G replacement and Pneumocystis jirovecii pneumonia (PJP) prophylaxis and/or experienced multiple childhood pneumonias (patient group 1) had an expansion of effector memory CD8+ T-cells with the senescent phenotype when compared to HCs. Such changes were not observed in the patient group 2 (four patients, 16, 22, 24, and 33 years old) who were life-long adherents to prophylaxis and experienced few infectious complications. CyTOF analysis of CD8+ T-cells from the 5-year-old patient and older adult HCs showed similar expression patterns of senescence-associated molecules. CONCLUSIONS: Our findings support that recurrent infections and non-adherence to prophylaxis promote early CD8+ T-cell senescence in CD40L deficiency. Premature senescence may increase malignant susceptibilities and further exacerbate infectious risk in CD40L-deficient patients.

Pancreatic neuroendocrine tumor presenting in indolent systemic mastocytosis: A case report.

INTRODUCTION: Systemic mastocystosis, a disorder of clonal mast cell expansion presents with symptoms of flushing, pruritus, musculoskeletal pain, gastrointestinal cramping and vascular instability. Patients with neuroendocrine tumors may present with similar symptoms due to the release of vasoactive mediators in both diseases. We report the co-occurrence of systemic mastocytosis and a neuroendocrine pancreatic tumor for which the patient received disease-specific treatment. CASE PRESENTATION: A 58-year-old woman with a history of indolent systemic mastocytosis and a serum tryptase of 51 ng/mL was diagnosed with a solid pancreatic lesion on ultrasound when assessing for organomegaly. Lesional biopsy was consistent with a pancreatic neuroendocrine tumor which was successfully resected. DISCUSSION: Presenting symptoms such as skin rashes, flushing, fatigue and diarrhea, are similar for systemic mastocytosis and neuroendocrine tumors. The co-occurrence of both diseases has not been previously reported. Activating mutations in KIT, which are a hallmark of systemic mastocytosis, may drive neoplastic proliferation in neuroendocrine tumors. Furthermore, mast cells infiltrating pancreatic tissue may have a trophic effect on the development of pancreatic neuroendocrine tumors. CONCLUSION: While challenging to diagnose both diseases presenting with similar symptoms, recognition of these distinct diseases is necessary to ensure timely treatment.

NAPDH Oxidase-Specific Flow Cytometry Allows for Rapid Genetic Triage and Classification of Novel Variants in Chronic Granulomatous Disease.

PURPOSE: Chronic granulomatous disease (CGD) is an innate immune deficiency, primarily affecting the phagocytic compartment, and presenting with a diverse phenotypic spectrum ranging from severe childhood infections to monogenic inflammatory bowel disease. Dihydrorhodamine (DHR) flow cytometry is the standard diagnostic test for CGD, and correlates with NADPH oxidase activity. While there may be genotype correlation with the DHR flow pattern in some patients, in several others, there is no correlation. In such patients, assessment by flow cytometric evaluation of NADPH oxidase-specific (NOX) proteins provides a convenient and rapid means of genetic triage, though immunoblotting has long been used for this purpose. METHODS AND RESULTS: We describe the clinical utility of the NOX flow cytometry assay through assessment of X-linked and autosomal recessive CGD patients and their first-degree relatives. The assessment of specific NOX proteins was correlated with overall NADPH oxidase function (DHR flow), clinical phenotype and genotype. NOX-specific protein assessment is a valuable adjunct to DHR assessment and genotyping to classify and characterize CGD patients. CONCLUSIONS: The atypical clinical presentation of some CGD patients can make genotype-phenotype correlation with DHR flow data challenging. Genetic testing, while useful for confirmation of diagnosis, can take several weeks, and in some patients does not provide a conclusive answer. However, NADPH-oxidase-specific protein flow assessment offers a rapid alternative to identification of the underlying genetic defect in cellular subsets, and can be utilized as a reflex test to an abnormal DHR flow. Further, it can provide insight into correlation between oxidative burst relative to protein expression in granulocytes and monocytes.

Eosinophillic Myocarditis Secondary to Metastatic Melanoma.

Eosinophilic myocarditis is a rare form of myocarditis that may manifest from cancer-mediated inflammation. A case of eosinophilic myocarditis secondary to metastatic melanoma is described; metastatic melanoma can cause a T helper type 2 lymphocyte-mediated increase in circulating levels of interleukin-5, which is known to stimulate eosinophil proliferation resulting in myocardial inflammation and fibrosis. Cardiac imaging with transesophageal echocardiography revealed a large immobile left ventricular apical thrombus. Cardiac MRI was then performed and revealed enhancing fibrosis along the endocardial surface. © RSNA, 2019 Supplemental material is available for this article.

Eosinophillic Myocarditis Secondary to Metastatic Melanoma.

Eosinophilic myocarditis is a rare form of myocarditis that may manifest from cancer-mediated inflammation. A case of eosinophilic myocarditis secondary to metastatic melanoma is described; metastatic melanoma can cause a T helper type 2 lymphocyte-mediated increase in circulating levels of interleukin-5, which is known to stimulate eosinophil proliferation resulting in myocardial inflammation and fibrosis. Cardiac imaging with transesophageal echocardiography revealed a large immobile left ventricular apical thrombus. Cardiac MRI was then performed and revealed enhancing fibrosis along the endocardial surface. © RSNA, 2019 Supplemental material is available for this article.

Consequences of B-cell-depleting therapy: hypogammaglobulinemia and impaired B-cell reconstitution.

Rituximab is a chimeric monoclonal antibody used to treat hematologic and autoimmune diseases by depleting CD20-expressing B cells. Patients may develop hypogammaglobulinemia following treatment, with some demonstrating failure of B-cell recovery. The true frequency of hypogammaglobulinemia and/or impaired B-cell reconstitution post rituximab is unknown due to the lack of prospective studies in different patient cohorts. The clinical significance remains controversial; some patients have recurrent infections while others are relatively asymptomatic. The aim of this review is to describe the prevalence of hypogammaglobulinemia and the associated risk for developing severe infection, in patients with differing underlying clinical conditions treated with rituximab. This may facilitate classification and prognostication of patients who develop these conditions and identify patients who may be at high risk of developing these complications, including those who may benefit from immunoglobulin replacement therapy.

Persistent immune thrombocytopenia heralds the diagnosis of Mycobacterium chimaera prosthetic valve endocarditis.

A 63 year old female was admitted for investigation of worsening renal insufficiency. During hospitalization she developed persistent immune thrombocytopenia refractory to supportive or immunosuppressive treatment. She was diagnosed with Mycobacterium chimaera prosthetic valve endocarditis and thrombocytopenia resolved with anti-mycobacterial therapy.

Leptomeningeal carcinomatosis as the primary presentation of relapse in breast cancer.

Leptomeningeal metastasis (LM) is an uncommon presentation of relapse in breast cancer, which is associated with poor clinical outcomes and poor prognosis. Notably, LM most commonly occurs in breast cancer. The aim of the present review was to investigate the occurrence of LM as the primary presentation of relapse following remission in breast cancer patients and to determine whether specific histological subtypes are predisposed to meningeal metastases. In addition, the present review evaluated whether patients presenting with LM as the primary site of relapse exhibit differences in survival when compared with patients exhibiting metastasis to other sites. Cross-sectional studies have demonstrated that LM is commonly associated with other sites of distant metastasis including lung, liver and bone metastases. The histological breast cancer subtype most commonly associated with LM was invasive lobular carcinoma, while triple-negative breast cancer patients appear to be predisposed to the development of LM when considering the overall prevalence of histological breast cancer subtypes. At present, data regarding LM as the primary site of relapse are limited due to its rarity as the first site of metastasis in breast cancer. Case-controlled studies are required to investigate the incidence of LM as the primary site of recurrence in breast cancer patients as this would enable treatment standardization and identification of prognostic factors for improved survival.