Newborn Screening for Severe Combined Immunodeficiency in the US: Current Status and Approach to Management.

In the US, the assay of T cell receptor excision circles (TRECs) in newborn dried blood spot specimens to detect severe combined immunodeficiency (SCID) was first piloted in 2008 in the state of Wisconsin. It has been rapidly adopted with 49 states and Puerto Rico now either routinely screening all newborns or planning to do so in 2017. Advances in SCID NBS over the last 9 years have revolutionized the ability to detect SCID and has led to profound improvement in outcomes of affected children

Subcutaneous Immunoglobulin Replacement Therapy with Hizentra® is Safe and Effective in Children Less Than 5 Years of Age.

BACKGROUND:Hizentra® (IGSC 20%) is a 20% liquid IgG product approved for subcutaneous administration in adults and children 2 years of age and older who have primary immunodeficiency disease (PIDD). There is limited information about the use of IGSC 20 % in very young children including those less than 5 years of age. METHODS:A retrospective chart review involved 88 PIDD infants and children less than 5 years of age who received Hizentra®. RESULTS:The mean age at the start of Hizentra® was 34 months (range 2 to 59 months). IGSC 20 % was administered weekly to 86 infants (two additional infants received twice weekly and three times weekly infusions, respectively) and included an average of 63 infusions (range 6-182) for an observation period up to 45.5 months. Infusion by manual delivery occurred in 15 patients. The mean dose was 674 mg/kg/4 weeks. The mean IgG level was 942 mg/dL while on IGSC 20 %, compared to a mean trough IgG level of 794 mg/dL (p < 0.0001) during intravenous or subcutaneous IgG administration prior to IGSC 20 %. Average infusion time was 47 (range 5-120) minutes, and the median number of infusion sites was 2 (range 1-4). Local reactions were mostly mild and observed in 36/88 (41%) children. No serious adverse events were reported. A significant increase in weight percentile (7 % ± 19.2, p = 0.0012) among subjects was observed during IGSC 20% administration. The rate of serious bacterial infections was 0.067 per patient-year while receiving IGSC 20%, similar to previously reported efficacy studies. CONCLUSIONS:Hizentra® is effective in preventing infections, and is well tolerated in children less than age 5 years

Hematopoietic Cell Transplantation in Patients With Primary Immune Regulatory Disorders (PIRD): A Primary Immune Deficiency Treatment Consortium (PIDTC) Survey.

Primary Immune Regulatory Disorders (PIRD) are an expanding group of diseases caused by gene defects in several different immune pathways, such as regulatory T cell function. Patients with PIRD develop clinical manifestations associated with diminished and exaggerated immune responses. Management of these patients is complicated; oftentimes immunosuppressive therapies are insufficient, and patients may require hematopoietic cell transplant (HCT) for treatment. Analysis of HCT data in PIRD patients have previously focused on a single gene defect. This study surveyed transplanted patients with a phenotypic clinical picture consistent with PIRD treated in 33 Primary Immune Deficiency Treatment Consortium centers and European centers. Our data showed that PIRD patients often had immunodeficient and autoimmune features affecting multiple organ systems. Transplantation resulted in resolution of disease manifestations in more than half of the patients with an overall 5-years survival of 67%. This study, the first to encompass disorders across the PIRD spectrum, highlights the need for further research in PIRD management

Clinical Experience With an L-Proline–Stabilized 10 % Intravenous Immunoglobulin (Privigen®): Real-Life Effectiveness and Tolerability

PURPOSE: This retrospective study evaluated the effectiveness and tolerability in clinical practice of an L-proline–stabilized 10 % intravenous immunoglobulin (IVIG; Privigen®) in patients with primary (PID) or secondary immunodeficiency (SID). METHODS: Patients from 6 centers in Europe and the US were treated with individually determined regimens of Privigen® for ≥3 months. Serum immunoglobulin G (IgG) trough levels, annualized rates of infection, hospitalization and antibiotics use, and the incidence of adverse events (AEs) were analyzed. RESULTS: Of 72 patients, three infants with severe combined immunodeficiency (SCID) were analyzed separately. The remaining 69 patients (52.2 % male; median age 38 years [range: 0.1–90.0]) with PID (82.6 %) or SID (17.4 %) received a mean (±standard deviation) Privigen® dose of 532 ± 250 mg/kg/month resulting in trough serum IgG levels of 407–1,581 mg/dL (median: 954 mg/dL). Ten patients (14.5 %) experienced 11 serious bacterial infections over 22.0 ± 15.0 months of treatment (0.087 events/patient/year, upper one-sided 99 % confidence interval: 0.170), the most common being pneumonia (11.6 %). The rates for any infection and hospitalization were 1.082 events/patient/year and 3.63 days/patient/year, respectively. Two patients with severe disease accounted for 303 of 460 hospital days. Across all 72 patients, 13 (18.1 %) patients experienced AEs, including 10 (13.9 %) patients with AEs at least possibly related to Privigen®, including headache (8.3 %), fever, and chills (2.8 % each). No related serious AEs were reported. One infant with SCID died due to severe viral infection. CONCLUSIONS: Despite the heterogeneous population, effectiveness and tolerability of Privigen® in clinical practice closely matched those reported in clinical studies

Newborn Screening for Severe Combined Immunodeficiency in the US: Current Status and Approach to Management

In the US, the assay of T cell receptor excision circles (TRECs) in newborn dried blood spot specimens to detect severe combined immunodeficiency (SCID) was first piloted in 2008 in the state of Wisconsin. It has been rapidly adopted with 49 states and Puerto Rico now either routinely screening all newborns or planning to do so in 2017. Advances in SCID NBS over the last 9 years have revolutionized the ability to detect SCID and has led to profound improvement in outcomes of affected children

Treatment of infants identified as having severe combined immunodeficiency by means of newborn screening.

Severe combined immunodeficiency (SCID) is characterized by severely impaired T-cell development and is fatal without treatment. Newborn screening (NBS) for SCID permits identification of affected infants before development of opportunistic infections and other complications. Substantial variation exists between treatment centers with regard to pretransplantation care, and transplantation protocols for NBS identified infants with SCID, as well as infants with other T-lymphopenic disorders detected by using NBS. We developed approaches to management based on the study of infants identified by means of NBS for SCID who received care at the University of California, San Francisco (UCSF). From August 2010 through October 2016, 32 patients with NBS-identified SCID and leaky SCID from California and other states were treated, and 42 patients with NBS-identified non-SCID T-cell lymphopenia were followed. Our center's approach supports successful outcomes; systematic review of our practice provides a framework for diagnosis and management, recognizing that more data will continue to shape best practices

Alterations in regulatory T cell subpopulations seen in preterm infants

Regulatory T cells are a population of CD4+ T cells that play a critical role in peripheral tolerance and control of immune responses to pathogens. The purpose of this study was to measure the percentages of two different regulatory T cells subpopulations

Alterations in Regulatory T Cell Subpopulations Seen in Preterm Infants

<div><p>Regulatory T cells are a population of CD4+ T cells that play a critical role in peripheral tolerance and control of immune responses to pathogens. The purpose of this study was to measure the percentages of two different regulatory T cells subpopulations, identified by the presence or absence of CD31 (Recent thymic emigrants and peripherally induced naïve regulatory T cells), in term and preterm infant cord blood. We report the association of prenatal factors, intrauterine exposure to lipopolysaccharide and inflammation and the percentages of these regulatory T cell subpopulations in term and preterm infants. Cord blood samples were collected from both term and preterm infants and mononuclear cells isolated over a Ficoll-Hypaque cushion. Cells were then stained with fluorochrome-labeled antibodies to characterize regulatory T cell populations and analyzed with multi-color flow cytometry. Cord blood plasma C-reactive protein, and lipopolysaccharide were also measured. Placental pathology was also examined. We report a gestational age-dependent difference in the percentage of total regulatory T cells, in which preterm infants of lower gestational ages have an increased percentage of regulatory T cells. We report the presence of two populations of regulatory T cells (CD31+ and CD31-) in cord blood of term and preterm infants and their association with different maternal and fetal characteristics. Factors associated with differences in the percentage of CD31- Tregs included the use of prenatal antibiotics, steroids and magnesium sulfate. In addition, the percentage of CD31- Tregs was significantly higher in cord blood of preterm pregnancies associated with inflammation and prenatal lipopolysaccharide exposure. The peripheral Treg pool of preterm infants could be altered by prenatal exposure to inflammation and chorioamnionitis; however, the clinical implications of this finding are not yet understood.</p></div