Symptomatic hypoglycemia in a child with common variable immunodeficiency: Deficient anterior pituitary with variable immune deficiency (DAVID) syndrome.

Deficient anterior pituitary with variable immune deficiency (DAVID) syndrome is a rare condition characterized by symptomatic ACTH deficiency and primary hypogammaglobulinemia, caused by pathogenic variants of the nuclear factor kappa-B subunit 2 (NF-κB2) gene. We report the case of a 9-yr-old boy diagnosed with common variable immunodeficiency at the age of 3, who is under monthly intravenous immunoglobulin. The patient was admitted twice to the pediatric emergency service at the age of 9 due to symptomatic hypoglycemic events. During the hypoglycemic crisis, serum cortisol was low (< 0.1 µg/dL), ACTH level was inappropriately low (4.4 ng/L) and the ACTH stimulation test failed to raise the blood cortisol level. Pituitary magnetic resonance imaging showed a hypoplastic pituitary. Other pituitary deficiencies, primary hyperinsulinism and other metabolic diseases were excluded. He started hydrocortisone replacement treatment while maintaining immunoglobulin substitution and he remains asymptomatic. Molecular analysis revealed the heterozygous nonsense pathogenic variant, c.2557C>T (Arg853Ter) in the NF-κB2 gene. Thus, symptomatic hypoglycemia in a child with primary immunodeficiency should raise the suspicion of DAVID syndrome, prompting NF-κB2 molecular analysis, to allow timely and appropriated therapy and genetic counseling.

Trombose intracardíaca na doença de Behçet: evento com risco de vida.

An adolescent with a recent diagnostic of Behçet's Disease (BD) was admitted with fever and intracardiac lesions detected on a routine transthoracic echocardiography, suggestive of endocarditis. Due to the absence of improvement after several rounds of antibiotics the patient was submitted to contrast-enhanced cardiac MRI that showed signs of intracardiac thrombosis, superior vena cava syndrome and pulmonary thromboembolism. The patient underwent surgery to excise the lesions and has been treated with cyclophosphamide and high dose prednisolone achieving complete remission. Intracardiac thrombosis is a rare manifestation of BD, and is associated with a poor prognosis. These patients usually require a combination of anticoagulation and immunosuppression to achieve remission.

Carbamazepine-induced interstitial pneumonitis associated with pan-hypogammaglobulinemia.

Carbamazepine remains a first-line drug for treatment of epilepsy in children. A wide variety of side effects have been attributed to its use, including a mild involvement of the immune system, usually a transient decline in IgA. Pulmonary complications, including interstitial pneumonitis, were mainly described in adults, and are considered rare side effects. In this report we describe the first pediatric patient who developed a severe interstitial pneumonitis and a pan-hypogammaglobulinemia 2 months after starting carbamazepine. A gradual resolution of symptoms and complete immune recovery was observed after the drug withdrawal, but 6 months later our patient still has a marked reduction in lung volumes and decreased exercise tolerance. We suggest that immunoglobulins should be carefully examined after carbamazepine initiation, particularly if the patient develops any sign of immunosuppression.

Omalizumab in the treatment of eosinophilic esophagitis and food allergy.

Omalizumab is currently used in severe asthma and has been tried in other allergic disorders. The authors report two patients with multiple food allergies and eosinophilic esophagitis on a very restrictive diet who have been treated with omalizumab, in order to improve food intolerance--the major distressing factor in their lives. The patients significantly improved in the reported symptoms. However, no improvement was seen regarding esophageal endoscopy and histology. Given the poor histological and endoscopy response, eosinophilic esophagitis persistence is unlikely to be IgE dependent. Omalizumab may improve the quality of life of patients with severe food allergy by improving symptoms, but it does not appear to change endoscopic and histological features of eosinophilic esophagitis in a short follow-up.

Clinical features and outcome of patients with IRAK-4 and MyD88 deficiency.

Autosomal recessive interleukin-1 receptor-associated kinase (IRAK)-4 and myeloid differentiation factor (MyD)88 deficiencies impair Toll-like receptor (TLR)- and interleukin-1 receptor-mediated immunity. We documented the clinical features and outcome of 48 patients with IRAK-4 deficiency and 12 patients with MyD88 deficiency, from 37 kindreds in 15 countries.The clinical features of IRAK-4 and MyD88 deficiency were indistinguishable. There were no severe viral, parasitic, and fungal diseases, and the range of bacterial infections was narrow. Noninvasive bacterial infections occurred in 52 patients, with a high incidence of infections of the upper respiratory tract and the skin, mostly caused by Pseudomonas aeruginosa and Staphylococcus aureus, respectively. The leading threat was invasive pneumococcal disease, documented in 41 patients (68%) and causing 72 documented invasive infections (52.2%). P. aeruginosa and Staph. aureus documented invasive infections also occurred (16.7% and 16%, respectively, in 13 and 13 patients, respectively). Systemic signs of inflammation were usually weak or delayed. The first invasive infection occurred before the age of 2 years in 53 (88.3%) and in the neonatal period in 19 (32.7%) patients. Multiple or recurrent invasive infections were observed in most survivors (n = 36/50, 72%).Clinical outcome was poor, with 24 deaths, in 10 cases during the first invasive episode and in 16 cases of invasive pneumococcal disease. However, no death and invasive infectious disease were reported in patients after the age of 8 years and 14 years, respectively. Antibiotic prophylaxis (n = 34), antipneumococcal vaccination (n = 31), and/or IgG infusion (n = 19), when instituted, had a beneficial impact on patients until the teenage years, with no seemingly detectable impact thereafter.IRAK-4 and MyD88 deficiencies predispose patients to recurrent life-threatening bacterial diseases, such as invasive pneumococcal disease in particular, in infancy and early childhood, with weak signs of inflammation. Patients and families should be informed of the risk of developing life-threatening infections; empiric antibacterial treatment and immediate medical consultation are strongly recommended in cases of suspected infection or moderate fever. Prophylactic measures in childhood are beneficial, until spontaneous improvement occurs in adolescence.

Pyogenic bacterial infections in humans with MyD88 deficiency.

MyD88 is a key downstream adapter for most Toll-like receptors (TLRs) and interleukin-1 receptors (IL-1Rs). MyD88 deficiency in mice leads to susceptibility to a broad range of pathogens in experimental settings of infection. We describe a distinct situation in a natural setting of human infection. Nine children with autosomal recessive MyD88 deficiency suffered from life-threatening, often recurrent pyogenic bacterial infections, including invasive pneumococcal disease. However, these patients were otherwise healthy, with normal resistance to other microbes. Their clinical status improved with age, but not due to any cellular leakiness in MyD88 deficiency. The MyD88-dependent TLRs and IL-1Rs are therefore essential for protective immunity to a small number of pyogenic bacteria, but redundant for host defense to most natural infections.

Mutations in STAT3 and IL12RB1 impair the development of human IL-17-producing T cells.

The cytokines controlling the development of human interleukin (IL) 17--producing T helper cells in vitro have been difficult to identify. We addressed the question of the development of human IL-17--producing T helper cells in vivo by quantifying the production and secretion of IL-17 by fresh T cells ex vivo, and by T cell blasts expanded in vitro from patients with particular genetic traits affecting transforming growth factor (TGF) beta, IL-1, IL-6, or IL-23 responses. Activating mutations in TGFB1, TGFBR1, and TGFBR2 (Camurati-Engelmann disease and Marfan-like syndromes) and loss-of-function mutations in IRAK4 and MYD88 (Mendelian predisposition to pyogenic bacterial infections) had no detectable impact. In contrast, dominant-negative mutations in STAT3 (autosomal-dominant hyperimmunoglobulin E syndrome) and, to a lesser extent, null mutations in IL12B and IL12RB1 (Mendelian susceptibility to mycobacterial diseases) impaired the development of IL-17--producing T cells. These data suggest that IL-12Rbeta1- and STAT-3--dependent signals play a key role in the differentiation and/or expansion of human IL-17-producing T cell populations in vivo.