Phenotype, penetrance, and treatment of 133 cytotoxic T-lymphocyte antigen 4-insufficient subjects

BACKGROUND

Cytotoxic T-lymphocyte antigen 4 (CTLA-4) is a negative immune regulator. Heterozygous CTLA4 germline mutations can cause a complex immune dysregulation syndrome in human subjects.

OBJECTIVE

We sought to characterize the penetrance, clinical features, and best treatment options in 133 CTLA4 mutation carriers.

METHODS

Genetics, clinical features, laboratory values, and outcomes of treatment options were assessed in a worldwide cohort of CTLA4 mutation carriers.

RESULTS

We identified 133 subjects from 54 unrelated families carrying 45 different heterozygous CTLA4 mutations, including 28 previously undescribed mutations. Ninety mutation carriers were considered affected, suggesting a clinical penetrance of at least 67%; median age of onset was 11 years, and the mortality rate within affected mutation carriers was 16% (n = 15). Main clinical manifestations included hypogammaglobulinemia (84%), lymphoproliferation (73%), autoimmune cytopenia (62%), and respiratory (68%), gastrointestinal (59%), or neurological features (29%). Eight affected mutation carriers had lymphoma, and 3 had gastric cancer. An EBV association was found in 6 patients with malignancies. CTLA4 mutations were associated with lymphopenia and decreased T-, B-, and natural killer (NK) cell counts. Successful targeted therapies included application of CTLA-4 fusion proteins, mechanistic target of rapamycin inhibitors, and hematopoietic stem cell transplantation. EBV reactivation occurred in 2 affected mutation carriers after immunosuppression.

CONCLUSIONS

Affected mutation carriers with CTLA-4 insufficiency can present in any medical specialty. Family members should be counseled because disease manifestation can occur as late as 50 years of age. EBV- and cytomegalovirus-associated complications must be closely monitored. Treatment interventions should be coordinated in clinical trials.

Magnetic resonance imaging in children and adolescents with chronic inflammatory bowel disease

Inflammatory bowel diseases (IBD) represent challenges, both from a diagnostic, and therapeutic point of view. Deep-seated anatomic structures are difficult to assess by ultrasound technique alone. As radiation-free alternative cross-sectional imaging method, magnetic resonance imaging of the intestinal structures is costly and time-consuming. Examination of pediatric patients imply additional considerations: reduction of body motions in younger children and consideration of the most appropriate preparation, and examination technique. The demanding Sellink technique is the only means for appropriately distending the lesser intestine in order to detect small bowel strictures. Oral intake of contrast medium (CM) alone shows its limitations regarding distensibility. The need for intravenous contrast media application needs to be considered, too. Active inflammation of both intestinal wall, and mesentery can be demonstrated accurately. Nevertheless, viable alternatives to CM application is desirable, considering non-negligible adverse reactions. Recent data suggest diffusion weighted imaging might fill this diagnostic gap. Irrespective of sequence technique chosen, bowel movement remains a major obstacle. Antispasmolytics in their function as smooth muscle relaxants help in improving image quality, however, their use in children might be off-label. Optimal preparation for the examination and appropriate imaging technique allow for diagnosing typical patterns of changes in IBD, such as bowel wall thickening, ulcers, mural stratification, strictures, creeping fat, and comb sign, and lymphadenopathy. The article gives a detailed overview of current significance of magnetic resonance imaging pediatric patients suffering from IBD, considering indications, limitations, and safety aspects.

Multiple viral infections after haploidentical hematopoietic stem cell transplantation in a child with acute lymphoblastic leukemia

After allogeneic hematopoietic stem cell transplantation (HSCT), viral infections/reactivations are a frequent complication, sometimes with fatal outcome. Thus, early diagnosis is recommended by screening of whole blood or plasma preparations using highly sensitive molecular techniques that test for the most common viral pathogens, such as Epstein-Barr virus, cytomegalovirus, and adenoviruses (ADVs). Despite this approach, not every reactivation/infection can be adequately detected or excluded, even with highly sensitive polymerase chain reaction. Particularly after toxic treatment, uncommon infections or infections resistant to first-line treatment can occur, even in unusual locations. Herein, we present the case of a child with Philadelphia chromosome-positive acute lymphoblastic leukemia after allogeneic HSCT who suffered from 5 different viral reactivations/infections, including acyclovir-resistant herpes simplex virus type 1 esophagitis, human herpesvirus 6 encephalitis, rotavirus gastroenteritis, respiratory syncytial virus pneumonia, and ADV esophagitis, despite routinely performed blood examinations for viral pathogens remaining unrevealing at all times.

Der Patient mit Ornithintranscarbamylasemangel

Ornithine transcarbamylase deficiency (OTCD) is the most common inborn urea cycle disorder. Patients with OTCD are at risk of acute metabolic decompensation with hyperammonemia and subsequent encephalopathy, coma and death. Symptoms may be triggered by infections, drugs and stress, evoked by trauma, pain, fear, surgery and anaesthesia or by episodes of protein catabolism, i.e. fasting-induced, post partum or during gastrointestinal bleeding. Several specific considerations must be made for anaesthetic and intensive care management in patients with this disease in order to avoid metabolic decompensation. We report the intensive care management of the first manifestation of late-onset OTCD in a 16-year-old girl and a course of inconspicuous general anaesthesia with midazolam, s-ketamine, fentanyl and isoflurane in a 22-year-old girl with known OTCD.