Genetic Evaluation of the Patients with Clinically Diagnosed Inborn Errors of Immunity by Whole Exome Sequencing: Results from a Specialized Research Center for Immunodeficiency in Türkiye.

Molecular diagnosis of inborn errors of immunity (IEI) plays a critical role in determining patients' long-term prognosis, treatment options, and genetic counseling. Over the past decade, the broader utilization of next-generation sequencing (NGS) techniques in both research and clinical settings has facilitated the evaluation of a significant proportion of patients for gene variants associated with IEI. In addition to its role in diagnosing known gene defects, the application of high-throughput techniques such as targeted, exome, and genome sequencing has led to the identification of novel disease-causing genes. However, the results obtained from these different methods can vary depending on disease phenotypes or patient characteristics. In this study, we conducted whole-exome sequencing (WES) in a sizable cohort of IEI patients, consisting of 303 individuals from 21 different clinical immunology centers in Türkiye. Our analysis resulted in likely genetic diagnoses for 41.1% of the patients (122 out of 297), revealing 52 novel variants and uncovering potential new IEI genes in six patients. The significance of understanding outcomes across various IEI cohorts cannot be overstated, and we believe that our findings will make a valuable contribution to the existing literature and foster collaborative research between clinicians and basic science researchers.

Heterogeneity in RAG1 and RAG2 deficiency: 35 cases from a single-centre.

Recombination activating genes (RAG)1 and RAG2 deficiency leads to combined T/B-cell deficiency with varying clinical presentations. This study aimed to define the clinical/laboratory spectrum of RAG1 and RAG2 deficiency. We retrospectively reviewed the clinical/laboratory data of 35 patients, grouped them as severe combined immunodeficiency (SCID), Omenn syndrome (OS), and delayed-onset combined immunodeficiency (CID) and reported nine novel mutations. The male/female ratio was 23/12. Median age of clinical manifestations was 1 months (mo) (0.5-2), 2 mo (1.25-5), and 14 mo (3.63-27), age at diagnosis was 4 mo (3-6), 4.5 mo (2.5-9.75), and 27 mo (14.5-70) in SCID (n = 25; 71.4%), OS (n = 5; 14.3%), and CID (n = 5; 14.3%) patients, respectively. Common clinical manifestations were recurrent sinopulmonary infections 82.9%, oral moniliasis 62.9%, diarrhea 51.4%, and eczema/dermatitis 42.9%. Autoimmune features were present in 31.4% of the patients; 80% were in CID patients. Lymphopenia was present in 92% of SCID, 80% of OS, and 80% of CID patients. All SCID and CID patients had low T (CD3, CD4, and CD8), low B, and increased NK cell numbers. Twenty-eight patients underwent hematopoietic stem cell transplantation (HSCT), whereas seven patients died before HSCT. Median age at HSCT was 7 mo (4-13.5). Survival differed in groups; maximum in SCID patients who had an HLA-matched family donor, minimum in OS. Totally 19 (54.3%) patients survived. Early molecular genetic studies will give both individualized therapy options, and a survival advantage because of timely diagnosis and treatment. Further improvement in therapeutic outcomes will be possible if clinicians gain time for HSCT.

A single center experience on PI3K/AKT/MTOR signaling defects: Towards pathogenicity assessment for four novel defects.

BACKGROUND: Phosphoinositide 3 kinases (PI3K) are lipid kinases expressed in lymphocytes/myeloid cells. PI3K/AKT/mTOR signaling defects present with recurrent infections, autoimmunity, lymphoproliferation, and agammaglobulinemia. OBJECTIVE: To characterize the PI3K/AKT/mTOR pathway defects and perform pathway analyses to assess novel variant pathogenicity. METHODS: We included 12 patients (heterozygous PIK3CD (n = 9) and PIK3R1 (n = 1) (activated PI3K delta syndrome (APDS) with gain-of-function mutations) and homozygous PIK3R1 variant (n = 2)), performed clinical/laboratory/genetic evaluation, and flow cytometric PI3K/AKT/mTOR pathway analyses. RESULTS: Median age at onset of complaints was 17.5 months (3 months to 12 years) and at diagnosis was 15.7 years (2.5-37) in APDS. Median diagnostic delay was 12.9 years (1.6-27). Recurrent respiratory tract infections (90%), lymphoproliferation (70%), autoimmune/inflammatory findings (60%), and allergy (40%) were common in APDS. Recurrent viral infections were present in 4/10 and malignancy (non-Hodgkin lymphoma and testicular yolk sac tumor) was present in 2/10 in APDS. Low CD4+ T cells(5/8) with increased CD4+ effector memory (8/8) and CD4+ TEMRA cells (6/8) were present in the given number of APDS patients. We diagnosed tubulointerstitial nephritis, Langerhans cell histiocytosis, and late-onset congenital adrenal hyperplasia in APDS. Allergic findings, lymphoproliferation/malignancy, and high IgM were present in the APDS but not in PIK3R1 deficiency. Low IgM/IgG/CD19+ B cell counts were characteristic in patients with PIK3R1 homozygous loss-of function mutations. CONCLUSION: Differential diagnosis with combined immunodeficiency and diseases of immune dysregulation make molecular genetic analysis crucial for diagnosing mTOR pathway defects. It is easy to differentiate APDS and homozygous PIK3R1 defects with specific laboratory features. Additionally, mTOR pathway functional analysis is a definitive diagnostic and pathogenicity assessment tool for novel APDS mutations.

The Etiology, Clinical Features, and Severity of Anaphylaxis in Childhood by Age Groups.

INTRODUCTION: Anaphylaxis is a severe, potentially fatal systemic hypersensitivity reaction with an acute onset. Etiology, clinical presentation, risk factors, comorbidities of pediatric anaphylaxis may vary depending on the age of the child. OBJECTIVE: The aim of this study was to investigate the etiology, clinical features, management of anaphylaxis in infants, preschoolers, school-age children, and adolescents. METHODS: The patients presenting with anaphylaxis between January 2015 and December 2018 in a single pediatric tertiary hospital were evaluated retrospectively. Demographic data, the triggers, sign-symptoms, severity, and the management of anaphylaxis were recorded. RESULTS: 239 patients were included in the study, 62.3% of whom were boys. The median age was 6.7 (IQR 2.33-12.83) years. 23.8% of the patients were infants, 15.5% were preschoolers, 33.5% were school-age children, and 27.2% were adolescents. Anaphylaxis mostly occurred at home. The most common causative agents were foods (39.3%), drugs (30.1%), and venoms (15.9%) of all cases. Main food allergens were cow's milk and hen's eggs in infants, cow's milk and tree nuts in preschoolers, and tree nuts and legumes in school-age children. Cases of drug-induced anaphylaxis (DIA) were recorded mostly with antibiotics (40.3%), followed by NSAIDs (23.6%). The primary trigger of anaphylaxis was foods in infants and preschoolers and drugs in school-age children and adolescents. There was no difference between age groups in terms of the system involved and severity. Severe anaphylaxis was more common with DIA. Adrenaline was used in 69.8% of all cases with no significant difference between age groups. CONCLUSION: Etiology and symptoms of anaphylaxis may differ between age groups. Raising awareness, educating patients and their parents on anaphylaxis and its management is essential.

Evaluation of the Clinical Characteristics of Patients with Food Protein-Induced Enterocolitis Syndrome: A Multicenter Study.

INTRODUCTION: Food protein-induced enterocolitis syndrome (FPIES) is a rare non-IgE, cell-mediated food allergy disorder. We aimed to report the demographic characteristics, clinical features, and management of pediatric patients with FPIES. METHODS: This retrospective study included all children diagnosed with FPIES at the pediatric allergy departments of the participating twelve study centers from January 2015 to November 2020. RESULTS: A total of 73 patients (39 males, 53.4%) with a male/female ratio of 1.1 were included in the study. The median (interquartile ranges) age at symptom onset was 6 months (0.5-168, 4-9.5). The most frequent offending foods were cow's milk, egg's yolk, fish, and egg's white, identified in 38.4% (n = 28), 32.9% (n = 24), 21.9% (n = 16) and 20.5% (n = 15) of the patients, respectively. The total number of reported FPIES episodes was 290 (3.9 episodes per child). Oral food challenge (OFC) was performed in 54.8% (n = 40) of the patients, and tolerance was detected in 17 OFCs (42.5%) at a median age of 15 months (range 8-132 months). CONCLUSION: FPIES is a non-IgE-mediated food hypersensitivity that commonly affects infants and is often misdiagnosed. The pathophysiology of the disease remains unclear and the low awareness of FPIES among physicians and parents highlights the need for more education.

Prognosis of food-induced anaphylaxis in children: A single-center real-life study.

Background: Food allergies are known to resolve over time, but there is little information on the natural history of food-induced anaphylaxis (FIA). Objective: This study aimed to evaluate the natural history of FIA in children and determine the factors that affect prognosis. Methods: Children with FIA who were followed up for at least 3 years, between 2010 and 2020, were included. Patients' families were contacted by telephone to question their child's tolerance status and invite them for reevaluation if uncertain. The patients were grouped as tolerant or persistent according to parent reports or reevaluation results. Logistic regression analysis was performed to determine the factors that affected persistence. Results: The study included 185 patients (62.2% boys) with 243 anaphylactic reactions to various foods. Fifty-eight patients (31%) gained tolerance within a 3-year follow-up period. Tolerance rates were higher in patients with FIA to milk (40%) and egg (43.9%) compared with to tree nuts (18.8%), legumes (5.6%), and/or seafood (11.1%) (p < 0.001). In a multivariate analysis, risk factors for persistent FIA were multiple food anaphylaxis (odds ratio [OR] 3.755 [95% confidence interval {CI}, 1.134-12.431]; p = 0.030), total IgE > 100 kU/L (OR 5.786 [95% CI, 2.065-16.207]; p = 0.001), and skin-prick test wheal size > 10 mm (OR 4.569 [95% CI, 1.395-14.964]; p = 0 .012) at presentation. Conclusion: Approximately a third of the patients with FIA developed tolerance within 3 years. Clinicians should remember that children with food allergies, even anaphylaxis, may develop tolerance over time. Regular follow up and reevaluation of tolerance status are necessary to avoid unnecessary elimination.

Nutritional status of children with primary immunodeficiency: A single center experience.

BACKGROUND: Nutritional status in primary immunodeficiencies (PID) is a major factor influencing immune defense. We aimed to evaluate the nutritional status of patients with PID. METHODS: Demographic findings and anthropometric measurements of 104 patients were recorded for this cross-sectional study. RESULTS: Combined immunodeficiencies (n = 49), predominantly antibody deficiencies (n = 28) and phagocytic system disorders (n = 17), were the major disease groups. In total, 44 (42.3%) patients had at least one anthropometric measurement below -2 standard deviations. Chronic, acute, and mixed-type malnutrition were detected in 18.3%, 16.3%, and 7.7% of the patients, respectively. No significant difference was detected among groups regarding anthropometric measurements however higher malnutrition rates were observed in 'combined immune deficiency less profound than severe combined immuno deficiency' (52%), chronic granulomatous disease (66.6%), and X-linked agammaglobulinemia (50%) patients. Severe malnutrition was present in 22 (21.2%) of the patients, although it was not significant. It was more common in the phagocytic system disorder group. All patients in the severe combined immunodeficiency group had undergone hematopoietic stem cell transplantation and 50% of them had malnutrition. There was also no significant difference regarding age, sex, anthropometric indexes (Weight for age, lenght/height for age body mass index Z-scores), malnutrition types, and prevalence of malnutrition among three major disease groups. Only the hospitalization history inversely related to body mass index and weight for age Z-scores (P < 0.0001). In patients with malnutrition, daily caloric intake was at least 20% or more below the requirement. CONCLUSIONS: Regardless of the type of immunodeficiency, nutritional status was poor in PID and hospitalization is the most important determinant of nutritional status. Even after hematopoietic stem cell transplantation, nutritional support should be continued.

Evaluation of Clinical Properties and Diagnostic Test Results of Cephalosporin Allergy in Children.

INTRODUCTION: Beta-lactams (BLs) are one of the most frequent causes of drug hypersensitivity reactions (HRs), and cephalosporins are a widely used subclass of BLs, especially in children. The aim of this study was to evaluate the clinical features and diagnostic test results of pediatric patients evaluated for suspected cephalosporin allergy. METHODS: This study included patients who presented to our pediatric allergy clinic with a history of reactions attributed to cephalosporins between January 1, 2011, and December 31, 2019, and whose diagnostic tests were completed for the diagnosis. RESULTS: This study included 120 pediatric patients and 69 (57.5%) of them were girls. The median age was 38.63 (interquartile range 10.5-85.7) months. Reactions occurring within 1 h of drug intake were reported in 33 patients (27.5%). Reactions were maculopapular rash in 55 (45.8%) patients, urticaria and/or angioedema in 49 (40.8%), anaphylaxis in 11 (9.2%), severe cutaneous drug reaction in 4 (3.3%), and fixed drug reaction in 1 patient (0.83%). The most frequently suspected agent was cefixime in 41 patients (34.2%). In total, 30 (25%) patients were diagnosed as having cephalosporin hypersensitivity. Confirmation of HRs was also significantly more frequent among patients who were older (p: 0.000), who had taken the drug parenterally (p: 0.000) and with immediate reactions (p: 0.000). CONCLUSION: Cephalosporin allergy has been confirmed in approximately one-fourth of the patients evaluated for suspected cephalosporin allergy. Confirmation of HRs was significantly more common among patients who were older, had immediate reactions, and had taken the drug parenterally.

Evaluation of Hypersensitivity Reactions in Pediatric Patients Using Biological Drugs.

INTRODUCTION: Biological drugs are currently used for the treatment of chronic inflammatory, autoimmune, and neoplastic diseases. With their expanding indication spectrum and increasing use, hypersensitivity reactions to these drugs are also becoming more frequent. The present study aimed to report the incidence and the features of such reactions in pediatric patients using biologicals for the treatment of various diseases. METHODS: The medical records of pediatric patients treated with biological agents between October 1, 2011 and August 31, 2019 were reviewed and adverse reactions were evaluated retrospectively. RESULTS: During the study period, 211 patients (116 boys, 55%) used 21 different biological drugs for the treatment of various diseases. Their median age at the time of the first treatment was 139.9 (IQR: 92.2-187.8) months. Hematologic-oncologic diseases were the most common indication for biological therapy (97/211; 46.0%), followed by rheumatologic diseases (82/211; 38.9%). Of the 211 patients, 14 (6.64%) experienced reactions to biological drugs. The most common culprit agent was rituximab (57.1%). Most of the patients (85.7%) had a history of reactions either during the infusion or within 1 h after taking the drug. Five patients underwent desensitization to the culprit drug, while 7 other patients continued treatment with a reduced dose/infusion rate or premedication. Also 1 patient continued to take the drug without any additional treatment. CONCLUSION: It was reported that 6.64% of the patients who received biologic drug therapy for various reasons in our hospital had hypersensitivity. The most common culprit agent was rituximab, and most of the reactions were immediate reactions.

Perioperative hypersensitivity reactions during childhood and outcomes of subsequent anesthesia.

BACKGROUND: Pediatric perioperative hypersensitivity reactions are rare, and possibly life-threatening. Identification of precise etiology is crucial to circumvent future re-exposures. AIMS: We aim to evaluate the clinical features and triggers of perioperative hypersensitivity reactions in children, and determine the outcomes of subsequent general anesthesia. METHODS: A retrospective study was performed with patients who underwent skin testing for general anesthesia between 2007 and 2019. We noted demographic features and skin tests (neuromuscular blocking agents, induction agents, and antibiotics). We also recorded specific immunoglobulin Es or provocation results of drugs or substances (latex, chlorhexidine, and ethylene oxide) that patients were exposed to antecedent to the reaction. Telephone interviews were performed to determine the current status of the participants and reconsider subsequent anesthesia. RESULTS: We enrolled 50 children (58% male) with a suspected perioperative hypersensitivity reaction. The median age was 6.67 (4.4-11.5) years, and the median time between the reaction, and skin tests was 4 (1-36) months. The most common potential causative agents were neuromuscular blocking agents (n = 8), midazolam (n = 3), ketamine (n = 2), and propofol (n = 1). Three children exhibited hypersensitivity to more than one general anesthetics, and three patients were allergic to latex. Thirty-one patients received subsequent anesthesia, and only one patient had a hypersensitivity reaction. A previous history multiple of general anesthesia administration (≥2) increased the risk of reaction to neuromuscular blocking agents. CONCLUSION: Data on perioperative hypersensitivity reactions during childhood are rare due to limited diagnostic procedures. Different preference of general anesthetics may change the causative agent. Meticulous evaluation is necessary to safely administer subsequent anesthesia.

Evaluation of drug patch tests in children.

Background: Patch tests are used to diagnose nonimmediate T-cell-mediated drug hypersensitivity reactions. The aim of this study was to evaluate the results of patch tests performed with suspect drugs in children. Methods: Patients < 18 years of age who had a drug patch test at the pediatric allergy outpatient clinic of our hospital between January 2014 and January 2020 were included in the study. Age, sex, culprit drug(s), reaction characteristics, and patch test results were recorded from the patients' files. Results: A total of 105 drug patch tests were performed on 71 patients during the study period. The patients' median age was 7 years (interquartile range, 4-11 years), and 57.7% (n = 41) were boys. Twenty-three patients (32.3%) had severe cutaneous adverse reaction (Stevens-Johnson syndrome in 11, drug reaction with eosinophilia and systemic symptoms in 9, and acute generalized exanthematous pustulosis in 3 patients), 45 (63.3%) had maculopapular rashes, and 3 (4.2%) had fixed drug eruption. A total of 20 patch test results (28%) were positive: 18 of 44 patch tests (40.9%) with antiepileptic drugs and 2 of 48 patch tests (4.1%) with antibiotics. Positive results were obtained in 23% of the patch tests (6/26) in 20 patients with severe cutaneous adverse reactions and in 17.7% of the patch tests (14/79) in 51 patients with mild cutaneous reactions. No adverse reactions occurred during or after the patch tests. Conclusion: In our study, patch test positivity was more common with antiepileptic drugs and in patients with severe cutaneous drug reaction.

The impact of skin prick testing on pain perception and anxiety in children and parents.

BACKGROUND: Skin prick testing (SPT) is a major diagnostic tool in patients with allergic symptoms. The testing process may involve pain, anxiety, and stress on children and parents. OBJECTIVE: We aimed to measure the level of pain and anxiety before and after SPT in children and parents, and tried to identify predictive factors. METHODS: The children underwent SPT and parents completed the State Trait Anxiety Inventory (STAI) S-Anxiety before and after SPT, T-Anxiety before SPT. The study nurse completed Children's Hospital of Eastern Ontario Pain Scale (CHEOPS) scores (<5 years) or Wong-Baker FACES Pain Rating Scale (VAS), (≥5 years) after the SPT, in order to quantify pain. RESULTS: A total of 523 children (5.3 [2.8-9.1] [median, interquartile range] years old, 59.5% male) were evaluated. Parent gender was a predominant factor for anxiety, as mothers had a higher pre-test STAI (S-Anxiety) score, STAI (T-Anxiety), and post-test STAI (S-Anxiety) score than fathers (p < 0.001). Pre-test STAI (S-Anxiety) scores of parents decreased with increasing age (for 0-<5 years, 5-<12 years, and ≥12 years; [p for trend = 0.016]). The children tested on the back had higher VAS scores compared with the ones tested on the forearm [2[0-4] vs 2[0-2], [p = 0.005]). Risk factors determining higher general anxiety STAI (T-Anxiety) scores above the median were female sex for the parent (OR = 1.68; 95% CI [1.10-2.57]; p = 0.017), and parent's education level being greater than or equal to high school level (OR = 1.83; 95% CI [1.27-2.64]; p = 0.001). CONCLUSION: SPT may cause anxiety and pain in a subgroup of children particularly in younger age, and if performed on the back. Anxiety levels were higher in mothers, and in parents with high education levels.

Immediate local anesthetic reactions and diagnostic test results in pediatric patients.

BACKGROUND/OBJECTIVES: Adverse reactions to local anesthetics are relatively common, but proven IgE-mediated allergy is extremely rare. We aimed to determine the frequency of local anesthetic allergy in pediatric patients. PATIENTS AND METHODS: The medical records of 73 patients who presented to our clinic with a history of suspected allergic reaction to local anesthetics and underwent diagnostic testing between 2012 and 2020 were retrospectively analyzed. Diagnoses were based on case histories, skin tests, and subcutaneous challenge tests. RESULTS: A total of 75 test series were carried out on the 73 patients (43 boys; median [IQR] age 9.25 [7.26-14.25] years, range 3-17.8 years). The most commonly tested drugs were lidocaine (n = 38; 50.6%) and prilocaine (n = 15; 20%). Local anesthetic allergy was confirmed in one (1.3%) of the 73 patients by positive subcutaneous challenge test with mepivacaine. CONCLUSION: There are limited data in the current literature regarding local anesthetic allergies and diagnosis test results in pediatric patients. Proven local anesthetic allergy is less common than expected by society and physicians, and therefore diagnostic tests are needed for patients with no contra-indications such as severe or life-threatening reactions.

Evaluation of periodontal status and cytokine/chemokine profile of GCF in patients with severe congenital neutropenia.

Severe congenital neutropenia (SCN) is a primary immunodeficiency characterized by defect in neutrophil count. Increased risk of infections in addition to periodontal problems, such as ulcerations of oral mucosa, gingival inflammation, and rapid loss of attachment are common in the course of the disease. The aim of the present study is to define the causal relationship between the severity of periodontal inflammation and severe congenital neutropenia through identification of cytokine profile in gingival crevicular fluid (GCF). A case-control study was performed in patients diagnosed with SCN and healthy controls. Demographic data, the molecular defect, laboratory work-up were gathered from the hospital registry. Periodontal indices were recorded and GCF samples were analyzed using multiplex analysis for the simultaneous measurements of the particular cytokines and chemokines. The present study included 14 patients and 22 control subjects. Both groups were comparable in terms of age and sex. Severity of gingival inflammation measured by the criteria of Löe was higher in the SCN cases (p < 0.05). Moreover, GCF levels of IFN-α, TNF-α, IL-10, IL-13, IL-15, IL-17, IL-2, IL-7, IL-33, IP-10, MIG, MIP-1ß were significantly higher in the controls. Decreased cytokine secretion seems to correlate with the decrease in neutrophil counts. The severity of gingival inflammation in SCN patients may be due to the bacterial overgrowth and the change in the content of the oral flora due to the decreased neutrophil counts. Therefore, regular periodontal examinations, the motivation of oral hygiene as well as the compliance with therapy in SCN patients contribute to the periodontal health.

Systemic and large local reactions during subcutaneous grass pollen immunotherapy in children.

BACKGROUND: Subcutaneous immunotherapy (SCIT) is the allergen-specific curative treatment of allergic rhinitis. Adverse effects, most of which are local, can be observed during the immunotherapy. These adverse effects have been reported more frequently during the pollen season. The purpose of this study was to estimate the rate of local, large local, and systemic reactions during the treatment, to determine the relationship between adverse reactions and the season in which these reactions occur, as well as the risk factors for adverse reactions during the grass pollen-specific SCIT treatment in children. METHODS: We retrospectively collected and analyzed the data of 261 children who administered grass pollen SCIT between 2008 and 2018. RESULTS: A total of 261 children (177, 67.8% male), who received grass pollen SCIT, with a mean (±SD) age of 12.0 ± 3.0 years at the initiation of SCIT were enrolled to the study. The number of the patients who experienced local and large local reactions was 109 and 30, respectively. In addition, the number of the patients with systemic reactions was 35. After the 12 284 injections, local reactions occurred in 357 (2.9%), and this was followed by systemic reaction as 55 (0.4%) and large local reactions as 40 (0.3%). Frequency of local (P < .001) and systemic reactions (P = .003) was higher during grass pollen season than out of the grass pollen season. In multivariate analysis, initiation of SCIT during the grass pollen season [OR:7.351, 95%CI:1.532-35.279, P = .013] and experiencing local reactions [OR:4.214, 95%CI:2.159-8.224, P < .001] were independent predictors for the development of large local and systemic reactions. CONCLUSION: SCIT, in which only mild-to-moderate systemic reactions occurred, is safe for the treatment of allergic rhinitis in children. Our study revealed that previous local reactions and initiation of immunotherapy during the grass pollen season were the predictors for large local and systemic reactions during SCIT in children.

Results of NSAID provocation tests and difficulties in the classification of children with nonsteroidal anti-inflammatory drug hypersensitivity.

BACKGROUND: Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used in children and can frequently cause hypersensitivity reactions. Rates of confirmed NSAID hypersensitivity (NSAID-H) in children are low. OBJECTIVE: To evaluate the results of drug provocation tests (DPTs) with NSAIDs and to evaluate the difficulties encountered in the classification of NSAID-H in children. METHODS: The study included patients with suspected NSAID-H who were examined in our clinic between January 1, 2015, and December 31, 2018. Oral provocation tests with NSAIDs were performed and reactions were classified according to the European Academy of Allergy and Clinical Immunology position paper on NSAID-H. RESULTS: A total of 243 patients (57.2% male patients) presented with suspected NSAID-H during the study period. Of these, 168 patients (69.1%) had a history of reaction to ibuprofen. Isolated skin involvement was the most frequent symptom (86%). A total of 238 DPTs were performed with the suspected agents and 34 had positive results. The families of 12 patients refused provocation testing with the suspected agent or aspirin and these patients could not be diagnosed. Of the 231 patients, 47 patients (20.3%) received a diagnosis of NSAID-H. Twenty patients with NSAID-H could not be classified because their guardians did not consent to further testing with aspirin. CONCLUSION: Performing diagnostic tests is important in patients with no contraindications. Characterizing these reactions in children can be difficult because of the coexistence of indistinguishable symptoms in their history and DPTs, as well as the need for multiple provocation tests. Therefore, further research is needed on this subject.

Diagnostic value and safety of penicillin skin tests in children with immediate penicillin allergy.

Background: The first-line method in the diagnosis of patients who describe an immediate reaction after penicillin intake is a skin test (ST) with penicillin reagents. Objectives: We aimed to determine the safety and diagnostic value of penicillin STs in the diagnosis of immediate reactions to penicillins in pediatric patients. Methods: The study included pediatric patients with suspected immediate reaction to penicillin who were subjected to STs by using a standard penicillin test kit as well as suspected penicillin and the drug provocation tests (DPT) with the suspected penicillin at our clinic. Results: A total of 191 patients (53.9% boys) with a median age of 6.83 years (interquartile range, 4.2-12 years) were included in the study. The time from drug intake to the onset of reaction was ≤1 hour in 138 patients (72.3%) and 1 to 6 hours in 53 patients (27.7%). Penicillin allergy (PA) was confirmed by diagnostic tests in 36 of the 191 patients (18.8%). In multivariate logistic regression analysis, the history of both urticaria and angioedema (odds ratio [OR] 27.683 [95% confidence interval {CI}, 3.143-243.837]; p = 0.003) and anaphylaxis (OR 56.246 [95% CI, 6.598-479.489]; p < 0.001) were the main predictors of a PA diagnosis. Although ST results were positive in 23 patients (63.8%), 13 patients (26.2%) had positive DPT results despite negative ST results. The negative predictive value (NPV) of STs was calculated 92.2% (155/168). None of our patients experienced immediate or delayed systemic and/or local reactions in relation to the STs. Conclusion: A history of urticaria with angioedema and anaphylaxis were the main predictors of true PA in children with suspected immediate reactions. STs with penicillin reagents are safe for use in children. Although STs have a high NPV, DPT is the gold standard for diagnosis. DPTs should be performed as the final step of the diagnostic evaluation of PA in patients with negative ST results.

Predictors for late tolerance development in food protein-induced allergic proctocolitis.

Background: Food protein-induced allergic proctocolitis (FPIAP) is a non-immunoglobulin E (IgE) mediated food allergy that typically presents with blood-mixed mucoid stool. Objective: To identify the predictors that affect the tolerance development in infants with FPAIP and laboratory as well as clinical differences between patients with early and with late tolerance. Methods: A total of 185 infants with FPIAP were included. The patients were grouped and analyzed based on laboratory tests and clinical characteristics. Results: The median (interquartile range [IQR]) age of onset of symptoms was 2.0 months (1.0-3.0 months). Symptoms began in severe cases in patients (n = 23) at a younger median (IQR) age (1.5 months [0.7-2.0 months]) than the group with nonsevere presentation (median 2.0 months [IQR 1.5-3.0 months]) (p < 0.001). The frequency of neutropenia (<1500/mm³) (p = 0.045) and eosinophilia (450 mm³) (p = 0.018) was increased in severe cases. Concomitant IgE-related food allergy (odds ratio [OR] 3.595 [95% confidence interval {CI}, 1.096-11.788], p = 0.035), non-IgE-mediated multiple food allergy (OR 3.577 [95% CI, 1.595-8.018], p = 0.002), feeding with cow's milk-based formula (at least once during infancy) (OR 2.517 [95% CI, 1.188-5.333], p = 0.016), and late complementary feeding (OR 5.438 [95% CI, 2.693-10.981], p < 0.001) were the predictors for late tolerance development. The estimated optimal cutoff value for introduction of complementary foods for the resolution of allergy was 5.5 months, with 69.4% sensitivity, 74.4% specificity, and an area under the curve of 0.737 (95% CI, 0.626-0.812) (p < 0.001). Conclusion: This study showed that the early introduction of complementary feeding accelerates tolerance development in FPAIP. A longer duration of an elimination diet has no impact on the resolution of allergy. Physicians should consider conservative avoidance measures and earlier introduction of complementary feeding in FPIAP.

A Spectrum of Clinical Findings from ALPS to CVID: Several Novel LRBA Defects.

INTRODUCTION: Autosomal recessively inherited lipopolysaccharide-responsive beige-like anchor (LRBA) protein deficiency was shown to be responsible for different types of inborn errors of immunity, such as common variable immunodeficiency (CVID) and autoimmune lymphoproliferative syndrome (ALPS). The aim of this study was to compare patients with LRBA-related ALPS and LRBA-related CVID, to describe their clinical and laboratory phenotypes, and to prepare an algorithm for their diagnosis and management. METHODS: Fifteen LRBA-deficient patients were identified among 31 CVID and 14 possible ALPS patients with Western blotting (WB), primary immunodeficiency disease (PIDD) gene, next-generation panel screening (NGS), and whole exome sequencing (WES). RESULTS: The median age on admission and age of diagnosis were 7 years (0.3-16.5) and 11 years (5-44), respectively. Splenomegaly was seen in 93.3% (14/15) of the patients on admission. Splenectomy was performed to 1/5. Recurrent upper respiratory tract infections (93.3% (14/15)), autoimmune cytopenia (80% (12/15)), chronic diarrhea (53.3% (8/15)), lower respiratory tract infections (53.3% (8/15)), lymphoma (26.6% (4/15)), Evans syndrome (26.6% (4/15)), and autoimmune thyroiditis (20% (3/15)) were common clinical findings and diseases. Lymphopenia (5/15), intermittant neutropenia (4/15), eosinophilia (4/15), and progressive hypogammaglobulinemia are recorded in given number of patients. Double negative T cells (TCRαß+CD4-CD8-) were increased in 80% (8/10) of the patients. B cell percentage/numbers were low in 60% (9/15) of the patients on admission. Decreased switched memory B cells, decreased naive and recent thymic emigrant (RTE) Thelper (Th) cells, markedly increased effector memory/effector memory RA+ (TEMRA) Th were documented. Large PD1+ population, increased memory, and enlarged follicular helper T cell population in the CD4+ T cell compartment was seen in one of the patients. Most of the deleterious missense mutations were located in the DUF1088 and BEACH domains. Interestingly, one of the two siblings with the same homozygous LRBA defect did not have any clinical symptom. Hematopoietic stem cell transplantation (HSCT) was performed to 7/15 (46.6%) of the patients. Transplanted patients are alive and well after a median of 2 years (1-3). In total, one patient died from sepsis during adulthood before HSCT. CONCLUSION: Patients with LRBA deficiency may initially be diagnosed as CVID or ALPS in the clinical practice. Progressive decrease in B cells as well as IgG in ALPS-like patients and addition of IBD symptoms in the follow-up should raise the suspicion for LRBA deficiency. Decreased switched memory B cells, decreased naive and recent thymic emigrant (RTE) Th cells, and markedly increased effector memory/effector memory RA+ Th cells (TEMRA Th) cells are important for the diagnosis of the patients in addition to clinical features. Analysis of protein by either WB or flow cytometry is required when the clinicians come across especially with missense LRBA variants of uncertain significance. High rate of malignancy shows the regulatory T cell's important role of immune surveillance. HSCT is curative and succesful in patients with HLA-matched family donor.

Selective loss of function variants in IL6ST cause Hyper-IgE syndrome with distinct impairments of T-cell phenotype and function.

Hyper-IgE syndromes comprise a group of inborn errors of immunity. STAT3-deficient hyper-IgE syndrome is characterized by elevated serum IgE levels, recurrent infections and eczema, and characteristic skeletal anomalies. A loss-of-function biallelic mutation in IL6ST encoding the GP130 receptor subunit (p.N404Y) has very recently been identified in a singleton patient (herein referred to as PN404Y) as a novel etiology of hyper-IgE syndrome. Here, we studied a patient with hyper-IgE syndrome caused by a novel homozygous mutation in IL6ST (p.P498L; patient herein referred to as PP498L) leading to abrogated GP130 signaling after stimulation with IL-6 and IL-27 in peripheral blood mononuclear cells as well as IL-6 and IL-11 in fibroblasts. Extending the initial identification of selective GP130 deficiency, we aimed to dissect the effects of aberrant cytokine signaling on T-helper cell differentiation in both patients. Our results reveal the importance of IL-6 signaling for the development of CCR6-expressing memory CD4+ T cells (including T-helper 17-enriched subsets) and non-conventional CD8+T cells which were reduced in both patients. Downstream functional analysis of the GP130 mutants (p.N404Y and p.P498L) have shown differences in response to IL-27, with the p.P498L mutation having a more severe effect that is reflected by reduced T-helper 1 cells in this patient (PP498L) only. Collectively, our data suggest that characteristic features of GP130-deficient hyper-IgE syndrome phenotype are IL-6 and IL-11 dominated, and indicate selective roles of aberrant IL-6 and IL-27 signaling on the differentiation of T-cell subsets.