Normal Lymphocyte Subsets Research Articles

P20 Job syndrome: hyper IgE syndrome in a young girl with an acneiform rash

Abstract Hyper IgE syndrome (HIES1) is a rare, autosomal dominant, primary immunodeficiency characterized by eczema, recurrent staphylococcal skin infections, pneumonia, increased serum IgE and eosinophilia. It is caused by a heterozygous mutation in the STAT3 gene on chromosome 17q21 with variable expressivity. Nonimmunological findings including characteristic facies, hyperextensibility, long-bone fractures, aneurysms, craniosynostosis and dental abnormalities. We present the case of an 11-year-old girl referred to dermatology with an acneiform facial rash. Examination was consistent with papulo-pustular scarring acne of the face and back. Her history was also significant for recurrent MSSA bacterial lymphadenitis requiring incision and drainage over the proceeding 3 years. Her past medical history was significant for the development of moderate-severity infantile acne at 2 weeks of age, mild childhood eczema, recurrent childhood otitis media Staphylococcus infections resulting in grommet insertion, primary tooth retention requiring extraction and a fractured wrist at age 9 years. Because of the burden of infection the patient was referred to immunology in Crumlin. Investigations revealed mild neutropenia, marginally elevated IgA and IgM, normal eosinophils, marginally elevated IgE, normal lymphocyte subsets, intact complement pathways and normal oxidative burst test. Next-generation sequencing was significant for STAT3 gene mutation consistent with HIES. As there is no family history this likely represents a de novo mutation. The patient is currently on prophylactic azithromycin and low-dose isotretinoin with good effect. This case represents a patient with both immunological and nonimmunological features of HIES1, marginally elevated IgE, absence of eosinophils and negative family history.

IFIH1 deficiency causing neonatal herpes simplex virus encephalitis and recurrent retinitis

Homozygous loss-of-function variants in Interferon induced with helicase C domain 1 (IFIH1) leads to immunodeficiency with early onset recurrent and severe viral respiratory infections (Immunodeficiency 95; MIM 619773). Severe respiratory infections with RNA viruses such as rhinovirus and respiratory syncytial virus (RSV) are most characteristic of IFIH1 deficiency. IFIH1 encodes melanoma differentiation-associated protein 5 (MDA5), an intracellular sensor of mainly long double-stranded RNA (ds-RNA), a viral replication intermediate. When activated, MDA5 triggers antiviral pathways including increased transcription of Type 1-interferon. The antiviral role of MDA5 is best described for positive (+) RNA viruses such as Picornavirus family which produce long ds-RNA as a replication intermediate. We present a patient with neonatal herpes simplex virus (HSV) encephalitis and recurrent retinitis with homozygous variant of unknown significance (VUS) in IFIH1, c.2062A>G (p.Lys688Glu).Patient is a 10-year-old male, born of consanguineous parents from the United Arab Emirates. Past medical history is notable for neonatal HSV encephalitis, grade 3 intraventricular hemorrhage, cerebral palsy, epilepsy, optic atrophy and recurrent HSV retinitis. Patient has no additional history of severe or recurrent infections. No family history of recurrent or severe infections, malignancy, autoimmunity or autoinflammation.Immune evaluation demonstrated anemia with elevated mean corpuscular volume and mild elevation of platelets and monocytes. Patient had normal lymphocyte subsets, normal T and B cell subset distributions, protective vaccine titers and normal immunoglobins apart from mildly elevated immunoglobulin G. An Invitae primary immunodeficiency panel demonstrated homozygous VUS in IFIH1, c.2062A>G (p.Lys688Glu). This variant is not found in gnomAD or ClinVar and has a Combined Annotation Dependent Depletion score of 22.6. Functional testing demonstrated decreased interferon induction after stimulation with intracellular RNA, intracellular DNA and agonists of both Toll-like receptor 7 and 9. These findings are consistent with MDA5 deficiency given decreased interferon response with known MDA5 agonists.In summary, we describe a patient with recurrent and severe infections with a DNA virus and no known infections with respiratory RNA viruses. Both DNA and RNA viruses produce long ds-RNA as replication intermediates, an MDA5 agonist. This patient highlights the anti-viral role of MDA5 for both DNA and RNA viruses.

Fatal COVID-19 in an infant prompted an early diagnosis of ZNFX1 deficiency in a sibling

BackgroundNFX1-type zinc finger-containing 1 (ZNFX1) is an interferon-stimulated double-stranded RNA sensor that restricts the replication of RNA viruses in mice. ZNFX1 deficiency in humans is very rare; to date, only fifteen cases have been reported by Vavassori S et al. (10.1016/j.jaci.2021.03.045). The disease presented in all cases as severe viral infections complicated by multisystem inflammation evolved to multiorgan failure with a high mortality rate.Pediatric Allergy and Immunology Section at Queen Rania Children’s Hospital in Jordan had confirmed the diagnosis of ZNFX1 deficiency in an infant at his first presentation with severe viral illness based on the positive family history of one sibling death caused by complicated COVID-19 infection. Case presentationA 12-month-old boy was born to consanguineous parents, full-term, with no NICU admission. He was doing well till the age of four months when he was admitted to the hospital with fever, hypoactivity, and maculopapular skin rash. On admission, he was ill, hypoactive, and febrile, and a physical exam showed hepatosplenomegaly and maculopapular skin rash. His lab showed thrombocytopenia, elevated transaminases, hyperferritinemia, and high CRP; he was treated with broad-spectrum antibiotics, but he continued to deteriorate, and his infectious workup was unrevealing, including COVID-19 PCR.His older sibling died at eight months in 2020 when she got a COVID-19 infection, deceased after rapid deterioration evolved to multiorgan failure. Unfortunately, she had no stored DNA, as she was treated at a peripheral hospital.Based on this presentation and the fatal COVID-19 infection, pediatric immunology service got consulted; we did an immunological workup, which showed normal lymphocyte subsets, Immunoglobulins, and bacterial antibodies.Whole exome sequencing showed a homozygous frameshift mutation in the ZNFX1 gene, protein change defect had detected; p.Tyr555MetfsTer6, and nucleotide change variant: c.1663_1665delTACinsAT. Family screening showed heterozygous for the same variant in both parents and a healthy sibling. The patient was diagnosed with the hemophagocytic lymphohistiocytosis-like disease and treated with steroids, intravenous immunoglobulin, and antimicrobials, he showed complete recovery, and we are going to do bone marrow transplantation as his brother is 8/8 HLA matched.

A PATIENT WITH KABUKI SYNDROME AND HYPOGAMMAGLOBULINEMIA DEVELOPS BURKITT LYMPHOMA

<h3>Introduction</h3> Kabuki syndrome (KS) is a rare genetic disorder characterized by congenital abnormalities, autoimmunity, intellectual disability, distinctive facial abnormalities, and hypogammaglobulinemia. <h3>Case Description</h3> A 24-year-old male with KS and hypogammaglobulinemia presented to the emergency department (ED) with lower back pain and extremity paralysis. His previous genetic diagnosis of KS had a heterozygous novel variant causing a premature translational stop signal p.Pro235Alafs*6 in the KMT2D gene. The patient also has a history of congenital heart disease, autoimmune cytopenias, and longstanding hypogammaglobulinemia on/off replacement immunoglobulin with baseline IgG 300-400 mg/dL, low IgA 10-20 mg/dL, normal IgM 50-60 mg/dL, normal lymphocyte subsets, and absent protein and polysaccharide vaccine responses consistent with common variable immunodeficiency. On arrival at the ED, spinal imaging revealed a compression fracture and underlying mass. Right-axillary and bone marrow biopsies confirmed Burkitt lymphoma. He was treated with chemotherapy, radiation, and replacement immunoglobulin. He has suffered from pneumonia, adenovirus, ileus<b>,</b> heart failure, and stroke. Routine immunologic testing performed at time of diagnosis revealed normal complete blood cell count, mild transaminitis from baseline (AST/ALT 61/71 U/L), baseline immunoglobulins, and normal lymphocyte subsets. <h3>Discussion</h3> While KS is a well-known cause of hypogammaglobulinemia, the authors have identified only two other published cases of Burkitt lymphoma in KS. This case emphasizes the importance of oncological screening and that routine immunologic testing of lymphocyte subsets and immunoglobulins may not have abnormalities from baseline in patients with active lymphoma. A mild transaminitis, however, might be concerning for malignancy in these patients.

RARE CASE OF HOMOZYGOUS IFNAR1 DEFICIENCY IN A SAMOAN CHILD WITH DISSEMINATED VARICELLA AFTER VACCINATION

<h3>Introduction</h3> Autosomal recessive interferon alpha/beta receptor 1 (IFNAR1) deficiency increases susceptibility to live-attenuated vaccines and wild-type viruses. Currently 16 cases, half with Polynesian ancestry have been reported since the discovery in 2019. Most cases present with severe MMR or yellow fever vaccine-related disease. Some cases report severe SARS-CoV-2, herpes simplex, and enterovirus. Varicella vaccine-related disease has been hypothesized but not previously reported. <h3>Case Description</h3> A pediatric Samoan girl with congenital cardiac anomaly, otherwise healthy until receiving Varicella and MMR vaccines at 12 months. Two weeks later with presumed incomplete Kawasaki Disease with 10-day fever, red lips, and maculopapular rash, given IVIG and infliximab; also, positive SARS-CoV-2 PCR and IgG that admission. Developed diffuse vesicular rash 3 weeks after vaccination requiring re-admission for disseminated varicella. At 14 months, admitted again for acute respiratory failure with viral pericarditis, positive for rhinovirus/enterovirus on respiratory viral panel and varicella serum PCR. Samoan parents are first-degree cousins and her stillborn sister had significant homozygosity on genetic evaluation. Normal lymphocyte subsets, normal mitogen proliferation, absent antigen proliferation in vitro, and normal NK function. Intact humoral immunity. Primary immunodeficiency disease panel identified homozygous pathogenic variant in IFNAR1. Future live viral vaccines contraindicated. Managed with acyclovir with return to baseline. <h3>Discussion</h3> This case demonstrates a novel finding of homozygous IFNAR1 deficiency predisposing to disseminated varicella after vaccination. TNF inhibition may have also contributed. IFNAR1 deficiency should be considered in patients with severe varicella or other severe viral illnesses, especially after live-attenuated viral vaccines in those of Polynesian ancestry.

Off-label use of omalizumab in a 6-year-old child with severe atopic dermatitis.

Background: Atopic dermatitis (AD) is a common chronic inflammatory skin disorder that affects up to 3% of adults and 15%-20% of children across the world. Although the mainstay of treatment is topical corticosteroids and/or calcineurin inhibitors, a majority of patients will not achieve a control of their condition and will need systemic treatment with steroids and immunosuppressants (1). Omalizumab is a humanized anti-IgE antibody licensed by the European Medical Agency for treatment of severe allergic asthma and spontaneous chronic urticaria in children older than 6 and 12 years, respectively; and a promising efficacy of omalizumab in the treatment of severe refractory AD has been shown by the ADAPT randomized clinical trial (2).Case report: A 6-year-old male patient being treated and followed at a pediatric dermatology clinic for a diagnosis of AD since the age of 3 years, showed unresponsive disease to different topical treatment options and non-pharmacological measures. The patient was referred to our clinic for systemic treatment when his SCORAD index was 70/103. At our immunology clinic, we did an extensive workup to unveil a comorbid or underlying disease. His labs showed high IgE levels at 2500 IU/mL, hypereosinophilia, and normal IgA, IgM, and lymphocyte subsets. We started him on different lines of immunosuppressants, including cyclosporine, prednisolone, tacrolimus, and intensive topical treatment; however, the patient did not show any noticeable response for 2 years. We then started him on omalizumab 300 mg twice weekly, and the SCORAD index dropped to 57 at 12 weeks and 55 at 18 weeks. The drug is still well tolerated, and we were able to stop systemic steroids at 15 weeks of treatment.Conclusion: Off-label use of omalizumab in a 6-year-old child with refractory severe AD was effective and safe in controlling the disease even though conventional systemic immunosuppressants proved ineffective.

Splenic kaposiform hemangioendothelioma presenting as insidious consumptive coagulopathy

Splenic kaposiform hemangioendothelioma presenting as insidious consumptive coagulopathy

Low-Count Monoclonal B-Cell Lymphocytosis Persists after 7 Years of Follow-up and Confers a Higher Risk of Death

Monoclonal B-cell lymphocytosis (MBL) is characterized by the presence of low numbers of circulating clonal B cells that usually display highly-similar phenotypic features to chronic lymphocytic leukemia (CLL) cells. This entity is divided into high-count (MBLhi) and low-count (MBLlo), depending on the number of peripheral blood (PB) clonal B cells (higher vs. lower than 0.5x109/L, respectively). Whereas MBLhi is frequently detected in laboratory routine analyses and precedes CLL, MBLlo is mainly detected in population-based screening studies, making its biological and clinical significance elusive. Of note, prevalence of MBLlo is significantly higher than that of MBLhi and CLL, and increases with age, with a prevalence >20% among individuals older than 70y.Here, we re-evaluated 65/91 MBLlo subjects (54 CLL-like and 11 non-CLL-like) followed-up for >5 years (median of 7 years), using high-sensitivity flow cytometry. Cytogenetic alterations related to CLL (i.e. del13q14, trisomy 12, del11(q22-q23) and del17p13) and other chronic B-cell tumors were studied by iFISH in purified MBL clonal B cells.Overall, the clone size significantly increased (median of 2-3-fold) in 69% of MBLlo cases, but only one subject progressed to MBLhi. In parallel, the frequency of cytogenetic alterations increased over time (32% vs. 61% of cases at baseline and at follow-up, respectively). The absolute number of the major T- and NK-cell populations was also increased, but only among CLL-like cases with increased clone size. To prevent a potential age-related bias and to further confirm these findings, we compared the number of PB normal lymphocyte subsets in CLL-like MBLlo subjects vs . a large series of age- and gender-matched non-MBL healthy donors.Although progression to CLL was not observed, overall survival of MBLlo subjects was significantly reduced vs. non-MBL controls studied in parallel (P=0.03) plus the general population from the same region (P≤0.001), particularly among females (P=0.01); infection and cancer, were the main causes of death in MBLlo. In summary, despite mid-term progression from MBLlo to MBLhi and CLL appears to be unlikely, MBLlo clones persist at increased numbers usually carrying more genetic alterations, in association with higher-risk of death in comparison with healthy individuals, particularly among females. DisclosuresNo relevant conflicts of interest to declare.

Immune Recovery Refines the Prognostic Impact of Minimal Residual Disease on Overall and Progression Free Survivals after Frontline Fludarabine, Cyclophosphamide and Rituximab (FCR) in CLL Patients

Introduction: in chronic lymphocytic leukemia (CLL), treatment with FCR is the standard of care for treatment-naive and fit enough patients (pts). MRD threshold assessed 3 months after end of treatment (EOT) is considered as a surrogate for both progression free survival (PFS) and overall survival (OS). On the other hand, antibiotic prophylaxis is often started and maintained until CD4>200/mm3. We hypothesized that a monitoring of MRD versus normal immune cells recovery kinetics during follow-up (FU) could help refine the predictive power of MRD EOT evaluation, and allow identification of patients with increased risk of either infection and/or relapse.Methods: we prospectively collected fresh peripheral blood (PB) samples of 162 pts from 2 institutions in France (2006-2017) at the end of treatment (EOT), then every 6 months until month 24 (M24). We used 4-color flow cytometry to quantify both MRD (classified as 3 clusters: low (<10-4), intermediate (≥10-4 but <10-2) or high (≥10-2) level) and the reconstitution of normal lymphocyte subsets (CD4, CD8, NK). We plotted survival curves using Kaplan-Meier method and landmark analyses at different time points (9-15-21 months from day 1 cycle 1 FCR). Cox proportional model with time-dependent covariates (MRD, CD4, CD8 and NK counts) was also used to evaluate the correlation of covariates with outcomes.Results: one hundred and sixty-two pts (69% male, median age 58y) received a median of 6 courses of FCR. IGHV was mutated in 36.6%, and del13q was the most frequent cytogenetic abnormality (37.4%). Only 7 pts had del17p and/or mutation of TP53. After a median follow-up of 60.5 months, 46.3 % of pts have relapsed and/or died (median PFS estimation: 65.7 months, median OS not reached). At EOT, 65.3%, 27.2% and 7.5 % of pts achieved low, intermediate and high MRD respectively; 64.2% of pts had CD4≤200/mm3 while 35.8% had CD4>200/mm3.At landmark analysis of EOT, multivariate Cox model identified IgHV unmutated (HR 2.46), MRD intermediate (HR 3.3) or high (HR 19.57) (Figure 1), CD4 level (HR 1.22) as factors associated with PFS, and only MRD (HR 1.1) and CD4 counts (HR 1.2) were found to be associated with improved OS (Figure 2). In EOT intermediate MRD pts (n=34), those having EOT CD4≤200/mm3 had better 5-year PFS than those having CD4>200/mm3 (53.5% vs 7.7%, p=0.001) (Figure 3). This difference was not significant for low MRD pts (65% vs 58.9%, p=0.7). In landmark analysis at 21 months (=one year after EOT assessment), intermediate MRD pts (n=44) having CD4≤200/mm3 had significantly better 5-year PFS (85.7% vs 52.8%, p=0.0138). When performing successive landmark analyses on the whole population, CD4>200/mm3 was associated with worse 5-year PFS at EOT (34.1% vs 59.6%, p=0.016), 6 months (49.5% vs 58.8%, p=0.017) and 12 months (46.7% vs 68.3%, p=0.008) (Figure 4). In total, 20.4% of patients developed opportunistic infections, not correlated to CD4/CD8/NK counts.Conclusion: complementarily with MRD, CD4 count is an independent predictive factor of PFS and OS after FCR. As expected, MRD increase during FU is independently associated with worse PFS and OS, but CD4 counts at EOT and the first year post-FCR refine prognosis of the “MRD detectable” risk group (independently of CLL associated risk factors such as del17p/IgHV status). This is important in the interpretation and design of clinical trials dedicated to prolong PFS/OS using consolidation regimens based on MRD detection>10-4 in CLL. On the other hand, CD4>200/mm3 was not predictive of infectious events. [Display omitted] DisclosuresRecher:Celgene, Sunesis, Amgen, Novartis: Research Funding; Novartis, Celgene, Jazz, Sunesis, Amgen: Consultancy. Ysebaert:Janssen: Consultancy, Research Funding, Speakers Bureau.

Comprehensive comparison between 222 CTLA-4 haploinsufficiency and 212 LRBA deficiency patients: a systematic review

Cytotoxic T lymphocyte antigen 4 (CTLA-4) haploinsufficiency (CHAI) and lipopolysaccharide-responsivebeige-like anchor (LRBA) deficiency (LATAIE) are newly identified inborn errors of immunity with shared molecular pathomechanisms and clinical manifestations. In this review, we aimed to provide differential comparisons regarding demographic, clinical, immunological and molecular characteristics between these two similar conditions. A literature search was conducted in PubMed, Web of Science and Scopus databases and included studies were systematically evaluated. Overall, 434 (222 CHAI and 212 LATAIE) patients were found in 101 eligible studies. The CHAI patients were mainly reported from North America and western Europe, while LATAIE patients were predominantly from Asian countries. In CHAI, positive familial history (P<0·001) and in LATAIE, consanguineous parents (P<0·001) were more common. In CHAI patients the rates of granulomas (P<0·001), malignancies (P=0·001), atopy (P=0·001), cutaneous disorders (P<0·001) and neurological (P=0·002) disorders were higher, while LATAIE patients were more commonly complicated with life-threatening infections (P=0·002), pneumonia (P=0·006), ear, nose and throat disorders (P<0·001), organomegaly (P=0·023), autoimmune enteropathy (P=0·038) and growth failure (P<0·001). Normal lymphocyte subsets and immunoglobulins except low serum levels of CD9+ B cells (14·0 versus 38·4%, P<0·001), natural killer (NK) cells (21 versus 41·1%, P<0·001), immunoglobulin (Ig)G (46·9 versus 41·1%, P=0·291) and IgA (54·5 versus 44·7%, P=0·076) were found in the majority of CHAI and LATAIE patients, respectively. The most frequent biological immunosuppressive agents prescribed for CHAI and LATAIE patients were rituximab and abatacept, respectively. Further investigations into the best conditioning and treatment regimens pre- and post-transplantation are required to improve the survival rate of transplanted CHAI and LATAIE patients.

Real World Experience of Daratumumab: Evaluating Lymphopenia and Adverse Events in Multiple Myeloma Patients.

Multiple myeloma (MM) is an incurable disease with a limited life expectancy of five years from diagnosis. Uncontrolled disease or infections are the main causes of mortality. Daratumumab, a monoclonal antibody against CD38, is approved to treat patients with MM. Its target, CD38, is expressed not only on MM cells but also on common lymphoid precursors and subsets of normal lymphocytes. Daratumumab-induced lymphopenia is common, but its clinical significance is understudied. In this study, we report the baseline characteristics, rates of severe lymphopenia, infections, and clinical trajectory of multiple myeloma patients (n = 100) treated with daratumumab-based regimens at the Ohio State University Comprehensive Cancer Center. We discover high rates of infections, hospital utilization, and severe lymphopenia and identify risks factors for severe lymphopenia, such as low pretreatment absolute lymphocyte count (ALC) values. Severe lymphopenia persists in 23% of patients, resulting in worst survival outcomes. Our data underline the importance of monitoring ALC and consider future use of prophylactic measures or alternative regimens in subsets of MM patients.

NONRESOLVING PNEUMONIA: A RARE CASE OF PULMONARY CRYPTOCOCCOSIS IN AN IMMUNOCOMPETENT PATIENT

SESSION TITLE: Monday Medical Student/Resident Case Report Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/21/2019 02:30 PM - 03:15 PM INTRODUCTION: Cryptococcus Neoformans is a serious fungal infection common to HIV, lung transplant, and otherwise immunocompromised patients. Infection in the immunocompetent (IC) host is rare. We present an IC patient with nonresolving pneumonia found to have a cryptococcal infection. CASE PRESENTATION: A 36-year-old Chinese female non-smoker, no past medical history with multiple Emergency Department (ED) visits in the past month for cough and shortness of breath treated with levofloxacin was referred to the ED again for outpatient findings of lung abscess on CT lung. Symptoms now included intermittent fevers, orthopnea, dyspnea on exertion, and weight loss. She endorsed cough with yellow sputum and small amounts of hemoptysis in the preceding days. Vitals, physical examination, and labs including CBC, BMP, lactate, and coagulation studies were unremarkable. CT Chest revealed large areas of consolidation in the RLL with multiple cavitary areas consistent with pneumonia with lung abscess. Admitted for necrotizing pneumonia, she received an empiric 7-day course of IV antibiotics. Blood and sputum cultures were negative, tuberculosis was ruled out via sputum. Viral testing revealed HIV negative with normal lymphocyte subset panels. Rheumatologic workup was unremarkable. Bronchoalveolar lavage samples stained positive for cryptococcus (Figure 1-3). Serum cryptococcal antigen titer was 1:128. There was no evidence of disseminated disease or CNS involvement on CT head or lumbar puncture. The patient was started on fluconazole with a plan for CT Chest in 6 months. DISCUSSION: Cryptococcus ranges from asymptomatic colonization to life threatening disseminated disease. Pulmonary infection with cryptococcus is uncommon in the IC patient. When present it is usually asymptomatic, but symptomatic disease can rarely occur. Because of this there is delay in treatment as symptoms may be present for days to weeks before the diagnosis is made. There are reports of disseminated infection leading to meningitis in an IC host(1)(2). In a retrospective study of disseminated cryptococcal infection in HIV noninfected patients mortality reached 63%(3). CONCLUSIONS: Our patient did not have any identifiable risk factors for Cryptococcus. It is not a disease isolated to HIV or immunocompromised patients. When assessing a patient with a nonresolving pneumonia it is crucial to have a broad differential. The life-threatening risk of pulmonary infection progressing to severe pneumonia with respiratory failure or extrapulmonic dissemination, particularly to the CNS, is why it is important to make a timely diagnosis and initiate appropriate treatment. Reference #1: Kerkering, TM, Duma, RJ, and Shadomy, S. The evolution of pulmonary Cryptococcus.Ann Intern Med. 1981; 94: 611-616 Reference #2: Chu HQ, Li HP, He GJ. Analysis of 23 cases of pulmonary cryptococcosis. Chin Med J (Engl) 2004;117:1425–1427 Reference #3: Chuang YM, Ho YC, Chang HT, Yu CJ, Yang PC, Hsueh PR. Disseminated cryptococcosis in HIV-uninfected patients. Eur J Clin Microbiol Infect Dis. 2008;27(4):307–310 DISCLOSURES: No relevant relationships by Ajay Adial, source=Web Response No relevant relationships by Trisana Cox, source=Web Response No relevant relationships by Rammohan Gumpeni, source=Web Response No relevant relationships by Asma Iftikhar, source=Web Response No relevant relationships by Tereza Izakovich, source=Web Response No relevant relationships by Priyank Trivedi, source=Web Response

AUTOINFLAMMATORY DISORDER IN A PEDIATRIC PATIENT

Introduction Periodic fever syndromes are a subset of autoinflammatory conditions that typically manifest in childhood. They often are diagnostic dilemmas due to their heterogeneous presentations. It is important for immunologists to be familiar with the unique features of these disorders. We present the case of a patient with suspected autoinflammatory disorder whose evaluation is ongoing due to recurrence of symptoms and negative testing. Case Description A 7-year-old boy presented with recurrent, episodic fevers since 6 months of age. He had associated aphthous ulcers, enlarged tonsils, joint swelling/redness, and fatigue. A tonsillectomy and adenoidectomy performed for presumed PFAPA resulted in temporary resolution of fevers. Unfortunately, fevers, aphthous ulcers, and joint swelling returned, along with intermittent skin lesions/blisters. Course was further complicated by development of abnormal movements and motor tics. He had normal neurologic work-up including brain MRI and electroencephalography. Family history included grandmother with immunoglobulin G deficiency and mother with recurrent fevers that resolved with tonsillectomy. Primary immunodeficiency gene panel did not show pathogenic variant. He had variants of unknown significance in CASP10, RFXAP, STX11, and STXBP2. Extensive rheumatologic work-up was negative. Immune testing revealed normal lymphocyte subsets, complement, inflammatory markers, immunoglobulins, and vaccine titers. MHC class I and II expression were normal. Exome sequencing is pending. Discussion This case is challenging with its atypical presentation, negative laboratory evaluation, and persistent symptoms despite management with tonsillectomy and medications including cimetidine. The differential is wide and includes autoinflammatory disorders as well as autoimmune conditions. Periodic fever syndromes are a subset of autoinflammatory conditions that typically manifest in childhood. They often are diagnostic dilemmas due to their heterogeneous presentations. It is important for immunologists to be familiar with the unique features of these disorders. We present the case of a patient with suspected autoinflammatory disorder whose evaluation is ongoing due to recurrence of symptoms and negative testing. A 7-year-old boy presented with recurrent, episodic fevers since 6 months of age. He had associated aphthous ulcers, enlarged tonsils, joint swelling/redness, and fatigue. A tonsillectomy and adenoidectomy performed for presumed PFAPA resulted in temporary resolution of fevers. Unfortunately, fevers, aphthous ulcers, and joint swelling returned, along with intermittent skin lesions/blisters. Course was further complicated by development of abnormal movements and motor tics. He had normal neurologic work-up including brain MRI and electroencephalography. Family history included grandmother with immunoglobulin G deficiency and mother with recurrent fevers that resolved with tonsillectomy. Primary immunodeficiency gene panel did not show pathogenic variant. He had variants of unknown significance in CASP10, RFXAP, STX11, and STXBP2. Extensive rheumatologic work-up was negative. Immune testing revealed normal lymphocyte subsets, complement, inflammatory markers, immunoglobulins, and vaccine titers. MHC class I and II expression were normal. Exome sequencing is pending. This case is challenging with its atypical presentation, negative laboratory evaluation, and persistent symptoms despite management with tonsillectomy and medications including cimetidine. The differential is wide and includes autoinflammatory disorders as well as autoimmune conditions.

Suppression of Lymphocyte Functions by Plasma Exosomes Correlates with Disease Activity in Patients with Head and Neck Cancer.

Purpose: Head and neck cancers (HNCs) often induce profound immunosuppression, which contributes to disease progression and interferes with immune-based therapies. Body fluids of patients with HNC are enriched in exosomes potentially engaged in negative regulation of antitumor immune responses. The presence and content of exosomes derived from plasma of patients with HNC are evaluated for the ability to induce immune dysfunction and influence disease activity.Experimental Design: Exosomes were isolated by size-exclusion chromatography from plasma of 38 patients with HNC and 14 healthy donors. Morphology, size, numbers, and protein and molecular contents of the recovered exosomes were determined. Coculture assays were performed to measure exosome-mediated effects on functions of normal human lymphocyte subsets and natural killer (NK) cells. The results were correlated with disease stage and activity.Results: The presence, quantity, and molecular content of isolated, plasma-derived exosomes discriminated patients with HNC with active disease (AD) from those with no evident disease (NED) after oncologic therapies. Exosomes of patients with AD were significantly more effective than exosomes of patients with NED in inducing apoptosis of CD8+ T cells, suppression of CD4+ T-cell proliferation, and upregulation of regulatory T-cell (Treg) suppressor functions (all at P < 0.05). Exosomes of patients with AD also downregulated NKG2D expression levels in NK cells.Conclusions: Exosomes in plasma of patients with HNC carry immunosuppressive molecules and interfere with functions of immune cells. Exosome-induced immune suppression correlates with disease activity in HNC, suggesting that plasma exosomes could be useful as biomarkers of HNC progression. Clin Cancer Res; 23(16); 4843-54. ©2017 AACR.

CD70 as a novel target of CAR-T-cell therapy for gliomas.

148 Background: Gliomas are the most common primary malignant brain tumor and are uniformly lethal. Cancer immunotherapy has the potential to target gliomas; however, its antitumor effects are restricted by limitations in clinically useful tumor specific targets. Chimeric antigen receptor modified T-cell (CAR-T) therapy is a highly promising option for cancer treatment, due to its combination of precision antibody recognition and T-cell tumor-specific killing. CD70 is an antigen expressed by limited subsets of normal lymphocytes and dendritic cells but is aberrantly overexpressed by glioma cells, which makes it an outstanding glioma-antigen target. Methods: The gene and protein expression of CD70 were evaluated to identify its potential as a glioma target. Human and mouse versions of CD70-specific CAR-T cells were generated, and human primary GBM lines as well as murine lines (GL-261, KR-158B) were used as human and mouse tumor targets, respectively. The antitumor effect of the human and mouse CD70-sepecific CARs were tested in vitro and in orthotopic xenograft and syngeneic murine models. Results: CD70 is only overexpressed by tumor cells in a subset of low-grade gliomas and GBM. The elevated gene and protein expression are associated with increased tumor grade and poor patient survival. Co-culturing CD70-specific CAR-T cells with CD70-positive glioma cells resulted in potent secretion of IFN-gamma and tumor-specific killing in a CD70-dependent manner. Irradiation enhances CD70 expression on glioma cells and thus increases CAR T-cell recognition. Adoptive transfer of the human and mouse CD70 CAR-T cells resulted in tumor regression of immunocompetent and immunodeficient mice, respectively. Conclusions: CD70 can be an excellent tumor target for gliomas, and CD70-specific CAR-T cells have potent antitumor activity against CD70-positive gliomas both in vitro and in vivo. Our study provides crucial preclinical evidence to support the future clinical application of CD70 CAR-T cells to treat gliomas.

CD20 monoclonal antibody targeted nanoscale drug delivery system for doxorubicin chemotherapy: an in vitro study of cell lysis of CD20-positive Raji cells.

A monoclonal antibody targeted nanoscale drug delivery system (NDDS) for chemotherapy was evaluated in CD20-positive Raji cells in vitro. Nanoparticles were formed by the assembly of an amphiphilic polymer consisting of 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-methoxypolyethyleneglycol-2000 (DSPE-PEG2000). Active carbon nanoparticles (ACNP) were conjugated to the chemotherapeutic agent, doxorubicin (DOX), and the nanoliposome carrier, DSPE-PEG2000 and DSPE-PEG2000-NH2 conjugated to the human anti-CD20 monoclonal antibody that targets B-lymphocytes. This monoclonal antibody targeted nanoparticle delivery system for chemotherapy formed the active NDDS complex, ACNP-DOX-DSPE-PEG2000-anti-CD20. This active NDDS was spherical in morphology and had good dispersion in the culture medium. When compared with the effects on CD20-negative YTS cells derived from natural killer/T-cell lymphoma, the active NDDS, ACNP-DOX-DSPE-PEG2000-anti-CD20, demonstrated DOX delivery to CD20-positive Raji cells derived from Burkitt’s lymphoma (B cell lymphoma), resulting in increased cell killing in vitro. The intracellular targeting efficiency of the ACNP-DOX-DSPE-PEG2000-anti-CD20 complex was assessed by confocal laser microscopy and flow cytometry. The findings of this in vitro study have shown that the DSPE-PEG2000 polymeric liposome is an effective nanocarrier of both a monoclonal antibody and a chemotherapy agent and can be used to target chemotherapy to specific cells, in this case to CD20-positive B-cells. Future developments in this form of targeted therapy will depend on the development of monoclonal antibodies that are specific for malignant cells, including antibodies that can distinguish between lymphoma cells and normal lymphocyte subsets.

CGRA4: VENO‐OCCLUSIVE DISEASE WITH IMMUNODEFICIENCY (VODI) TREATED WITH HAPLO‐IDENTICAL BONE MARROW TRANSPLANT

Veno-Occlusive disease with Immunodeficiency (VODI) is a rare combined immunodeficiency. Mutations in SP110, have been described in the Lebanese population with VODI. Untreated, reported outcomes for VODI are 100% mortality at one year of life. Conservative management (PJP prophylaxis and Immunoglobulin) result in mortality of 75%. Bone marrow transplant has been demonstrated as the only definitive treatment, but has a high rate of complications. Haploidentical HSCT provides an opportunity for Stem Cell Transplantation in those where a matched donor is not available. Historically, Haploidentical HSCT has been limited by high rates of graft rejection, Graft-Versus-Host Disease (GVHD), Transplant-related mortality and poor immune reconstitution. We present the first case of VODI that has been managed with a TCR alpha/beta, CD19 depleted Haplo-identical HSCT. This patient, the first child to consanguineous Lebanese parents, presented at 4 months of age with a febrile illness, hepatomegaly and abdominal ascites. Immunoglobulins were undetectable and the patient had normal lymphocyte subsets. SP110 mutation was confirmed. Infections included CMV, confirmed on Whole Blood PCR, and Pneumocystis Jerovicii Pneumoniae (PJP) confirmed on Brochoalveolar Lavage PCR. The latter resulted in acute deterioration, for which the patient required High Frequency Oscillatory Ventilation prior to improvement with high-dose Bactrim. CMV infection was treated with Gancyclovir. Haploidentical HSCT was performed using a parent donor. Conditioning consisted of Treosulfan and Fludarabine. The patient engrafted on day 11. MMF was discontinued at day +35. Day +30 donor chimerism was 99%. The post-transplant course has been complicated by deranged liver function, presumed secondary to CMV as liver biopsy has demonstrated resolution of Veno-Occlusive Disease and no evidence of GVHD. This case highlights successful use of Haploidentical HSCT in treatment of VODI. Further evaluation is required with subsequent cases and long-term outcomes.

ASCIA‐P69: A NOVEL AICDA MUTATION IN A CASE OF AUTOSOMAL RECESSIVE HYPER‐IGM SYNDROME, GROWTH HORMONE DEFICIENCY AND AUTOIMMUNITY

The Hyper-immunoglobulin M syndromes (HIGM) or immunoglobulin class switch recombination (Ig-CSR) deficiencies are rare primary immunodeficiency (PID) disorders. A 9-year-old girl with recurrent ear infections and failure to thrive since the age of 6 months had normal lymphocyte subsets, but extremely elevated IgM and significantly decreased IgG and IgA. In view of the patient's short stature, growth hormone evaluation was carried out and growth hormone deficiency established. The patient underwent Ig replacement therapy and received short course of growth hormone therapy and responded well. Furthermore, the patient developed benign cervical lymphadenopathy, as well as elevated ESR, positive autoantibodies to SSA-Ro, and severely dry eyes, which partially responded to both the punctate occlusion and systemic corticosteroids, at the age of 7 years. Sequencing analysis of the exons from activation-induced cytidine deaminase ( AICDA ) gene revealed that the patient was homozygous for a single T to C transversion at position 455 in exon 4, which replaces a Valine with an Alanine. To our knowledge, this is a new AICDA mutation, which has not been reported previously in HIGM. Autoimmune complications have been formerly described in the reported series of AICDA deficient HIGM; however the association with growth hormone deficiency is rarely reported.

CAR-Engineered T Cells Specific for the Elotuzumab Target SLAMF7 Eliminate Primary Myeloma Cells and Confer Selective Fratricide of SLAMF7+ Normal Lymphocyte Subsets

Background: SLAMF7 (CS1, CD319) is uniformly and highly expressed in multiple myeloma (MM) where it promotes adhesion and survival of malignant plasma cells (mPCs) in the bone marrow niche. It is absent on normal solid organ tissues but known to be expressed on lymphocyte subsets (T, B and NK cells). Clinical evaluation of the anti-SLAMF7 monoclonal antibody (mAb) Elotuzumab (huLuc63) has resulted in marked reversible lymphodepletion and conferred potent anti-MM efficacy in combination therapy. Here, we evaluated the potential to generate SLAMF7-directed chimeric antigen receptor (CAR) modified T cells from previously treated MM patients and analyzed their potency against autologous mPCs as well as fratricidal activity against normal lymphocyte subsets.Methods: Flow cytometric analyses for SLAMF7 expression on mPCs and normal lymphocyte subsets of MM patients (n=67) and healthy donors (n=20) was performed using specific mAbs and matched isotype controls. A SLAMF7-specific CAR was constructed using the VH/VL targeting domains of mAb huLuc63, fused to an Ig-Fc spacer and a signaling module of CD3ζ and CD28. Lentiviral gene transfer was performed into CD3/CD28-bead stimulated bulk CD4+ and CD8+ T cells of MM patients (n=7). CAR transgene positive T cells were enriched using an EGFRt transduction marker and expanded for functional analyses.Results: We confirmed high SLAMF7 expression levels on mPCs in all analyzed samples and detected SLAMF7 expression on a fraction of normal lymphocytes obtained from peripheral blood of MM patients, including naïve and memory CD4+ (95% CI: 33-59%) and CD8+ T cells (75-95%), B cells (25-35%) and NK cells (94-98%). Remarkably, the proportion of SLAMF7+ cells was significantly higher in MM patients compared to healthy donors in all corresponding lymphocyte subsets (p<0.05). Despite high level SLAMF7 expression on the input T cell population, functional CD4+ and CD8+ T cells expressing the SLAMF7-CAR could be readily generated in all 7 MM patients, and expanded to therapeutically relevant doses in a single expansion cycle following enrichment (>107 cells). We analyzed the kinetics of SLAMF7 expression on CD4+ and CD8+ CAR T cells during the manufacturing process and detected rapid disappearance of SLAMF7+ T cells in T cell lines modified with the SLAMF7-CAR. By contrast unmodified T cells and T cell lines expressing a CD19-CAR retained a significant proportion of SLAMF7+ T cells, suggesting that expression of the SLAMF7-CAR induced killing of SLAMF7+ T cells. In vitro functional testing of SLAMF7-CAR CD4+ and CD8+ T-cell lines confirmed potent specific lysis of SLAMF7+ MM cell lines including MM1.S and OPM-2 and stable SLAMF7-transfectants of K562, as well as antigen specific IFNγ secretion and productive proliferation. In a flow cytometry based cytotoxicity assay, co-incubation of mPCs with autologous (or allogeneic) SLAMF7-CAR T cells resulted in elimination of >90% of mPCs after a 4-hour incubation period, whereas CD19-CAR or unmodified T cells had no discernible effects. Moreover, in an in vivo xenograft MM model (NSG/MM1.S) a single administration of SLAMF7-CAR T cells resulted in complete MM clearance and long-term survival, whereas mice treated with CD19-CAR or unmodified T cells rapidly expired from progressive disease. Finally, we analyzed the fratricidal potential of SLAMF7-CAR T cells to predict hematologic toxicities that might occur in a clinical setting. Co-incubation of purified CD4+ and CD8+ primary T cells, B cells and NK cells with SLAMF7-CAR T cells resulted in rapid and specific elimination of only SLAMF7+ subsets, whereas SLAMF7- cells remained viable and functional as confirmed for CD4+ and CD8+ T cells by inducible IFNγ secretion.Conclusion: Our data demonstrate that SLAMF7-specific CAR T cells can be reproducibly generated from MM patients and exert remarkable anti-myeloma efficacy in pre-clinical models in vitro and in vivo. Lymphocytic fratricide does not preclude the manufacture of SLAMF7-CAR T cells but might be associated with acute (cytokine storm) or chronic (viral infections) side effects in a clinical setting. However, such toxicities may be prevented e.g. by preparative lymphodepletion and antiviral prophylaxis and enable the implementation of SLAMF7-CAR T cell therapy as a safe and effective modality in the treatment of MM. DisclosuresKnop:Celgene Corporation: Consultancy. Einsele:Novartis: Consultancy, Honoraria, Speakers Bureau; Amgen/Onyx: Consultancy, Honoraria, Speakers Bureau; Janssen: Consultancy, Honoraria, Research Funding, Speakers Bureau; Celgene: Consultancy, Honoraria, Research Funding, Speakers Bureau.

Impact of folate therapy on combined immunodeficiency secondary to hereditary folate malabsorption

Hereditary folate malabsorption (HFM) is a rare autosomal recessive disorder. Severe folate deficiency in HFM can result in immunodeficiency. We describe a female infant with HFM who acquired severe Pneumocystis pneumonia. The objective of the present study was to elucidate her immunological phenotype and to examine the time course of immune recovery following parenteral folate therapy. The patient demonstrated a combined immunodeficiency with an impaired T cell proliferation response, pan-hypogammaglobulinemia, and an imbalanced pro-inflammatory cytokine profile. She had normal white blood cell count, normal lymphocyte subsets, and normal complement levels. Two novel mutations were identified within the SLC46A1 gene to produce a compound heterozygote. We confirmed full recovery of her immunological and neurophysiological status with parenteral folate replacement. The time course of recovery of her immunological profile varied widely, however. HFM should be recognized as a unique form of immunodeficiency.