T-cell deficiency induces deficits in social behavior and dyslipidemia in mice

Patients with neuropsychiatric disorders often exhibit an altered metabolic status. However, the underlying factors that induce behavioral and metabolic dysfunctions remain poorly understood. Therefore, we investigated whether behavioral and metabolic alterations could be induced in immunodeficient conditions. We found that T-cell-deficient Cd3e^-/- mice exhibit deficits in social behavior associated with dyslipidemia. Cd3e^-/- mice exhibited abnormal social novelty preference, but normal anxiety-like behavior. We also detected decreases in the concentrations of plasma triglyceride and the lipid transporter molecule fatty acid-binding protein 2. Furthermore, the adoptive transfer of T-cells to Cd3e^-/- mice ameliorated the deficits in social behavior and recovered plasma triglyceride concentration. Thus, we found that T-cell disruption can induce defects in social behavior and systemic lipid homeostasis in mice. Given these findings, we believe that Cd3e^-/- mice represent a useful tool for investigating the mechanisms of causal relationships among immune dysfunction, behavior, and metabolism.

Case Report: "Primary Immunodeficiency"-Severe Autoimmune Enteropathy in a Pediatric Heart Transplant Recipient Treated With Abatacept and Alemtuzumab

Disorders of immune dysregulation following heart transplantation in children have been reported; however, the management of such disorders remains uncertain and challenging. In this case report, we describe a clinical course of a child with severe autoimmune enteropathy after a heart transplant in infancy and detail a treatment approach with abatacept and alemtuzumab. A 21-month-old girl with a medical history of congenital dilated cardiomyopathy and heart transplantation at 2 months was evaluated for chronic hematochezia. The patient underwent an extensive workup, including endoscopic biopsy which showed crypt apoptosis, similar to that seen with graft-versus-host disease (GVHD). Results of her immune workup were consistent with status post-thymectomy but also demonstrated evidence of immune dysregulation. Specifically, her immune phenotype at diagnosis demonstrated T-cell lymphopenia, restricted TCR repertoire and skewing of T-cell compartment toward memory phenotype, increase in serum soluble ILR2a, and hypergammaglobulinemia. In the absence of response to more standard immune modulation, the patient was treated with CTLA4-Ig (abatacept), followed by a combination of abatacept and a JAK inhibitor and, finally, a combination of abatacept and alemtuzumab. Following therapy with alemtuzumab, the patient achieved remission for the first time in her life. Her clinical course was complicated by a relapse after 6 months which again readily responded to alemtuzumab. Ultimately, despite these remissions, the patient suffered an additional relapse. This case highlights the challenges of neonatal thymectomy and adds new insights into the pathogenesis, diagnosis, and management of severe autoimmune enteropathy in pediatric heart transplant recipients.

Hyper IgE Syndrome Associated With Warts: A First Case of Dedicator of Cytokinesis 8 Deficiency in the Philippines

Hyper IgE syndrome (HIES) encompasses a group of primary immunodeficiency diseases (PIDs) that is characterized by severe atopy, and recurrent infections and markedly elevated serum IgE levels. The majority of HIES cases suffer from autosomal dominant mutations in the signal transducer and activator of transcription 3 gene. A minority of cases display autosomal recessive inheritance, and one form is caused by mutations in the dedicator of cytokinesis 8 (DOCK8) gene. Here we describe the first recognized and diagnosed case of DOCK8 deficiency in the Philippines. A 14 year-old-girl was referred due to recalcitrant atopic dermatitis, recurrent sinopulmonary infections, with widespread warts on the face, trunk and extremities. She had no coarse facial features or retained primary teeth, whereas she presented with widespread viral skin infections and multiple allergic diseases. Laboratory examinations revealed elevations in eosinophil count and serum IgE. The level of T-cell receptor excision circles was undetectable. The patient was suspected to have HIES with a probable DOCK8 deficiency. Genetic analysis disclosed a large genomic deletion involving exons 2-4 in the DOCK8 gene. A combination of recalcitrant atopic dermatitis, asthma, food allergies, with viral skin infections should increase the physician's consideration of a PID. Patients with HIES accompanied by warts and T-cell deficiency can be strongly suspected to have DOCK8 deficiency.

A prospective study on the natural history of patients with profound combined immunodeficiency: An interim analysis

BACKGROUND

Absent T-cell immunity resulting in life-threatening infections provides a clear rationale for hematopoetic stem cell transplantation (HSCT) in patients with severe combined immunodeficiency (SCID). Combined immunodeficiencies (CIDs) and "atypical" SCID show reduced, not absent T-cell immunity. If associated with infections or autoimmunity, they represent profound combined immunodeficiency (P-CID), for which outcome data are insufficient for unambiguous early transplant decisions.

OBJECTIVES

We sought to compare natural histories of severity-matched patients with/without subsequent transplantation and to determine whether immunologic and/or clinical parameters may be predictive for outcome.

METHODS

In this prospective and retrospective observational study, we recruited nontransplanted patients with P-CID aged 1 to 16 years to compare natural histories of severity-matched patients with/without subsequent transplantation and to determine whether immunologic and/or clinical parameters may be predictive for outcome.

RESULTS

A total of 51 patients were recruited (median age, 9.6 years). Thirteen of 51 had a genetic diagnosis of "atypical" SCID and 14 of 51 of CID. About half of the patients had less than 10% naive T cells, reduced/absent T-cell proliferation, and at least 1 significant clinical event/year, demonstrating their profound immunodeficiency. Nineteen patients (37%) underwent transplantation within 1 year of enrolment, and 5 of 51 patients died. Analysis of the HSCT decisions revealed the anticipated heterogeneity, favoring an ongoing prospective matched-pair analysis of patients with similar disease severity with or without transplantation. Importantly, so far neither the genetic diagnosis nor basic measurements of T-cell immunity were good predictors of disease evolution.

CONCLUSIONS

The P-CID study for the first time characterizes a group of patients with nontypical SCID T-cell deficiencies from a therapeutic perspective. Because genetic and basic T-cell parameters provide limited guidance, prospective data from this study will be a helpful resource for guiding the difficult HSCT decisions in patients with P-CID.