Defining the Minimal Long-Term Follow-Up Data Elements for Newborn Screening.

Newborn screening (NBS) is hailed as a public health success, but little is known about the long-term outcomes following a positive newborn screen. There has been difficulty gathering long-term follow-up (LTFU) data consistently, reliably, and with minimal effort. Six programs developed and tested a core set of minimal LTFU data elements. After an iterative data collection process and the development of a data collection tool, the group agreed on the minimal LTFU data elements. The denominator captured all infants with an NBS diagnosis, accounting for children who moved or died prior to the follow-up year. They also agreed on three LTFU outcomes: if the child was still alive, had contact with a specialist, and received appropriate care specific to their diagnosis within the year. The six programs representing NBS public health programs, clinical providers, and research programs provided data across multiple NBS disorders. In 2022, 83.8% (563/672) of the children identified by the LTFU programs were alive and living in the jurisdiction; of those, 92.0% (518/563) saw a specialist, and 87.7% (494/563) received appropriate care. The core LTFU data elements can be applied as a foundation to address the impact of early diagnosis by NBS within and across jurisdictions.

Posttransplantation late complications increase over time for patients with SCID: A Primary Immune Deficiency Treatment Consortium (PIDTC) landmark study.

BACKGROUND: The Primary Immune Deficiency Treatment Consortium (PIDTC) enrolled children in the United States and Canada onto a retrospective multicenter natural history study of hematopoietic cell transplantation (HCT). OBJECTIVE: We investigated outcomes of HCT for severe combined immunodeficiency (SCID). METHODS: We evaluated the chronic and late effects (CLE) after HCT for SCID in 399 patients transplanted from 1982 to 2012 at 32 PIDTC centers. Eligibility criteria included survival to at least 2 years after HCT without need for subsequent cellular therapy. CLE were defined as either conditions present at any time before 2 years from HCT that remained unresolved (chronic), or new conditions that developed beyond 2 years after HCT (late). RESULTS: The cumulative incidence of CLE was 25% in those alive at 2 years, increasing to 41% at 15 years after HCT. CLE were most prevalent in the neurologic (9%), neurodevelopmental (8%), and dental (8%) categories. Chemotherapy-based conditioning was associated with decreased-height z score at 2 to 5 years after HCT (P < .001), and with endocrine (P < .001) and dental (P = .05) CLE. CD4 count of ≤500 cells/µL and/or continued need for immunoglobulin replacement therapy >2 years after transplantation were associated with lower-height z scores. Continued survival from 2 to 15 years after HCT was 90%. The presence of any CLE was associated with increased risk of late death (hazard ratio, 7.21; 95% confidence interval, 2.71-19.18; P < .001). CONCLUSION: Late morbidity after HCT for SCID was substantial, with an adverse impact on overall survival. This study provides evidence for development of survivorship guidelines based on disease characteristics and treatment exposure for patients after HCT for SCID.

Phase 3 Trial of Epicutaneous Immunotherapy in Toddlers with Peanut Allergy.

BACKGROUND: No approved treatment for peanut allergy exists for children younger than 4 years of age, and the efficacy and safety of epicutaneous immunotherapy with a peanut patch in toddlers with peanut allergy are unknown. METHODS: We conducted this phase 3, multicenter, double-blind, randomized, placebo-controlled trial involving children 1 to 3 years of age with peanut allergy confirmed by a double-blind, placebo-controlled food challenge. Patients who had an eliciting dose (the dose necessary to elicit an allergic reaction) of 300 mg or less of peanut protein were assigned in a 2:1 ratio to receive epicutaneous immunotherapy delivered by means of a peanut patch (intervention group) or to receive placebo administered daily for 12 months. The primary end point was a treatment response as measured by the eliciting dose of peanut protein at 12 months. Safety was assessed according to the occurrence of adverse events during the use of the peanut patch or placebo. RESULTS: Of the 362 patients who underwent randomization, 84.8% completed the trial. The primary efficacy end point result was observed in 67.0% of children in the intervention group as compared with 33.5% of those in the placebo group (risk difference, 33.4 percentage points; 95% confidence interval, 22.4 to 44.5; P<0.001). Adverse events that occurred during the use of the intervention or placebo, irrespective of relatedness, were observed in 100% of the patients in the intervention group and 99.2% in the placebo group. Serious adverse events occurred in 8.6% of the patients in the intervention group and 2.5% of those in the placebo group; anaphylaxis occurred in 7.8% and 3.4%, respectively. Serious treatment-related adverse events occurred in 0.4% of patients in the intervention group and none in the placebo group. Treatment-related anaphylaxis occurred in 1.6% in the intervention group and none in the placebo group. CONCLUSIONS: In this trial involving children 1 to 3 years of age with peanut allergy, epicutaneous immunotherapy for 12 months was superior to placebo in desensitizing children to peanuts and increasing the peanut dose that triggered allergic symptoms. (Funded by DBV Technologies; EPITOPE ClinicalTrials.gov number, NCT03211247.).

Improving Access to Therapy for Patients With Inborn Errors of Immunity: A Call to Action.

Breakthroughs in sequencing technology, targeted immunotherapy, and immune reconstituting treatment have increased the pool of patients with inborn errors of immunity, requiring expertise from clinical immunologists. A growing category of immunodeficiency, presenting as primary immune regulatory disorder and secondary immunodeficiency due to targeted immune therapy for cancer and autoimmunity, has added to the growing burden of patients needing access to immune-supportive therapy. The confluence of a growing population of patients needing a clinical immunologist, complex payer structures, and inadequate health care representation will exacerbate current problems with access to therapy. Patients, health care providers, researchers, public and private payers, and industry must come together to find solutions to improve access to therapy. In this article, we reviewed the major topics regarding access to therapy for patients with immunodeficiency.

PEGylated Recombinant Adenosine Deaminase Maintains Detoxification and Lymphocyte Counts in Patients with ADA-SCID.

PURPOSE: Metabolic detoxification with enzyme replacement therapy (ERT) promotes immune recovery in patients with adenosine deaminase (ADA)-deficient severe combined immunodeficiency (ADA-SCID). Elapegademase is a PEGylated recombinant bovine ADA ERT developed to replace the now-discontinued bovine-derived pegademase. This study was a 1-way crossover from pegademase to elapegademase in 7 patients with ADA-SCID to assess efficacy and safety outcomes for elapegademase. METHODS: After once-weekly pegademase dosage was adjusted to achieve therapeutic metabolic detoxification and trough ADA activity, patients transitioned to a bioequivalent dose of elapegademase. Maintenance of metabolic detoxification and adequate ADA activity were evaluated periodically. RESULTS: One patient withdrew after 2 doses of an early elapegademase formulation due to injection-site pain caused by EDTA. The 6 remaining patients completed 71-216 weeks of elapegademase therapy with a formulation that did not contain EDTA. In these patients, elapegademase improved ADA activity compared with pegademase and maintained metabolic detoxification. Total lymphocyte counts increased for all completer patients from between 1.2- and 2.1-fold at the end of study compared with baseline. Elapegademase had a comparable safety profile to pegademase; no patient developed a severe infectious complication. Three patients had transient, non-neutralizing antibodies to pegademase, elapegademase, and/or polyethylene glycol ≤ 47 weeks of treatment without effect on trough plasma ADA activity or trough erythrocyte deoxyadenosine nucleotide levels. CONCLUSION: Elapegademase was safe, well tolerated, achieved stable trough plasma ADA activity with weekly dosing, was effective in maintaining metabolic detoxification, and was associated with maintenance or improvements in lymphocyte counts compared with pegademase therapy in patients with ADA-SCID.

Impact of Genetic Diagnosis on the Outcome of Hematopoietic Stem Cell Transplant in Primary Immunodeficiency Disorders.

To evaluate the relationship between knowledge of genetic diagnosis before HSCT and outcome, we reviewed all HSCTs for primary immune deficiencies (PID) performed at UCSF from 2007 through 2018. SCID, a distinct entity identified since 2010 in California by newborn screening and treated early, was considered separately. The underlying genetic condition was known at the time of HSCT in 85% of cases. Graft failure was less frequent in patients with a genetic diagnosis (19% with a genetic diagnosis versus 47% without, p = 0.020). Furthermore, event-free survival and overall survival (OS) at 5 years were better for those with a genetic diagnosis (78% with versus 44% without, p = 0.006; and 93% versus 60% without, p = 0.0002, respectively). OS at 5 years was superior for known-genotype patients with both SCID (p = 0.010) and non-SCID PID (p = 0.010). There was no difference in OS between HSCT done in 2007-2010 compared to more recently (p = 0.19). These data suggest that outcomes of HSCT for PID with known genotype may reflect specific experience and literature, or that a substantial proportion of patients with PID of undetermined genotype may have had underlying conditions for which HSCT may carry greater risk. The higher rate of graft failure in PID with unknown genotype may be in part explained by insufficient conditioning, which in turn could be dictated by compromised organ function in patients undergoing HSCT late in the course. Widespread availability of PID gene sequencing as standard care can provide genetic diagnoses for most patients with PID prior to HSCT, permitting optimization of transplant approach.

Disease Progression of WHIM Syndrome in an International Cohort of 66 Pediatric and Adult Patients.

Warts, hypogammaglobulinemia, infections, and myelokathexis (WHIM) syndrome (WS) is a combined immunodeficiency caused by gain-of-function mutations in the C-X-C chemokine receptor type 4 (CXCR4) gene. We characterize a unique international cohort of 66 patients, including 57 (86%) cases previously unreported, with variable clinical phenotypes. Of 17 distinct CXCR4 genetic variants within our cohort, 11 were novel pathogenic variants affecting 15 individuals (23%). All variants affect the same CXCR4 region and impair CXCR4 internalization resulting in hyperactive signaling. The median age of diagnosis in our cohort (5.5 years) indicates WHIM syndrome can commonly present in childhood, although some patients are not diagnosed until adulthood. The prevalence and mean age of recognition and/or onset of clinical manifestations within our cohort were infections 88%/1.6 years, neutropenia 98%/3.8 years, lymphopenia 88%/5.0 years, and warts 40%/12.1 years. However, we report greater prevalence and variety of autoimmune complications of WHIM syndrome (21.2%) than reported previously. Patients with versus without family history of WHIM syndrome were diagnosed earlier (22%, average age 1.3 years versus 78%, average age 5 years, respectively). Patients with a family history of WHIM syndrome also received earlier treatment, experienced less hospitalization, and had less end-organ damage. This observation reinforces previous reports that early treatment for WHIM syndrome improves outcomes. Only one patient died; death was attributed to complications of hematopoietic stem cell transplantation. The variable expressivity of WHIM syndrome in pediatric patients delays their diagnosis and therapy. Early-onset bacterial infections with severe neutropenia and/or lymphopenia should prompt genetic testing for WHIM syndrome, even in the absence of warts.

Outcomes following treatment for ADA-deficient severe combined immunodeficiency: a report from the PIDTC.

Adenosine deaminase (ADA) deficiency causes ∼13% of cases of severe combined immune deficiency (SCID). Treatments include enzyme replacement therapy (ERT), hematopoietic cell transplant (HCT), and gene therapy (GT). We evaluated 131 patients with ADA-SCID diagnosed between 1982 and 2017 who were enrolled in the Primary Immune Deficiency Treatment Consortium SCID studies. Baseline clinical, immunologic, genetic characteristics, and treatment outcomes were analyzed. First definitive cellular therapy (FDCT) included 56 receiving HCT without preceding ERT (HCT); 31 HCT preceded by ERT (ERT-HCT); and 33 GT preceded by ERT (ERT-GT). Five-year event-free survival (EFS, alive, no need for further ERT or cellular therapy) was 49.5% (HCT), 73% (ERT-HCT), and 75.3% (ERT-GT; P < .01). Overall survival (OS) at 5 years after FDCT was 72.5% (HCT), 79.6% (ERT-HCT), and 100% (ERT-GT; P = .01). Five-year OS was superior for patients undergoing HCT at <3.5 months of age (91.6% vs 68% if ≥3.5 months, P = .02). Active infection at the time of HCT (regardless of ERT) decreased 5-year EFS (33.1% vs 68.2%, P < .01) and OS (64.7% vs 82.3%, P = .02). Five-year EFS (90.5%) and OS (100%) were best for matched sibling and matched family donors (MSD/MFD). For patients treated after the year 2000 and without active infection at the time of FDCT, no difference in 5-year EFS or OS was found between HCT using a variety of transplant approaches and ERT-GT. This suggests alternative donor HCT may be considered when MSD/MFD HCT and GT are not available, particularly when newborn screening identifies patients with ADA-SCID soon after birth and before the onset of infections. This trial was registered at www.clinicaltrials.gov as #NCT01186913 and #NCT01346150.

Drug Sensitivity of Vaccine-Derived Rubella Viruses and Quasispecies Evolution in Granulomatous Lesions of Two Ataxia-Telangiectasia Patients Treated with Nitazoxanide.

A strong association between rubella virus (RuV) and chronic granulomas, in individuals with inborn errors of immunity, has been recently established. Both the RA27/3 vaccine and wild-type RuV strains were highly sensitive to a broad-spectrum antiviral drug, nitazoxanide (NTZ), in vitro. However, NTZ treatment, used as a salvage therapy, resulted in little or no improvements of RuV-associated cutaneous granulomas in patients. Here, we report investigations of possible causes of treatment failures in two ataxia-telangiectasia patients. Although a reduction in RuV RNA in skin lesions was detected by real-time RT-PCR, live immunodeficiency-related vaccine-derived rubella viruses (iVDRV) were recovered from granulomas, before and after the treatments. Tizoxanide, an active NTZ metabolite, inhibited replications of all iVDRVs in cultured A549 cells, but the 50% and 90% inhibitory concentrations were 10-40 times higher than those for the RA27/3 strain. There were no substantial differences in iVDRV sensitivities, neither before nor after treatments. Analysis of quasispecies in the E1 gene, a suspected NTZ target, showed no effect of NTZ treatments on quasispecies' complexity in lesions. Thus, failures of NTZ therapies were likely due to low sensitivities of iVDRVs to the drug, and not related to the emergence of resistance, following long-term NTZ treatments.

When Screening for Severe Combined Immunodeficiency (SCID) with T Cell Receptor Excision Circles Is Not SCID: a Case-Based Review.

Newborn screening efforts focusing on the quantification of T cell receptor excision circles (TRECs), as a biomarker for abnormal thymic production of T cells, have allowed for the identification and definitive treatment of severe combined immunodeficiency (SCID) in asymptomatic neonates. With the adoption of TREC quantification in Guthrie cards across the USA and abroad, typical, and atypical SCID constitutes only ~ 10% of cases identified with abnormal TRECs associated with T cell lymphopenia. Several other non-SCID-related conditions may be identified by newborn screening in a term infant. Thus, it is important for physicians to recognize that other factors, such as prematurity, are often associated with low TRECs initially, but often improve with age. This paper focuses on a challenge that immunologists face: the diagnostic evaluation and management of cases in which abnormal TRECs are associated with variants of T cell lymphopenia in the absence of a genetically defined form of typical or atypical SCID. Various syndromes associated with T cell impairment, secondary forms of T cell lymphopenia, and idiopathic T cell lymphopenia are identified using this screening approach. Yet there is no consensus or guidelines to assist in the evaluation and management of these newborns, despite representing 90% of the patients identified, resulting in significant work for the clinical teams until a diagnosis is made. Using a case-based approach, we review pearls relevant to the evaluation of these newborns, as well as the management dilemmas for the families and team related to the resolution of genetic ambiguities.

Continuous and Daily Oral Immunotherapy for Peanut Allergy: Results from a 2-Year Open-Label Follow-On Study.

BACKGROUND: The randomized, controlled PALISADE trial demonstrated the benefit of daily oral immunotherapy with Peanut (Arachis Hypogaea) allergen powder-dnfp (PTAH, formerly AR101) in peanut-allergic children and adolescents. OBJECTIVE: ARC004, the open-label follow-on study to PALISADE, used 5 dosing cohorts to explore PTAH treatment beyond 1 year and alternative dosing regimens in peanut-allergic individuals. METHODS: Active arm (PTAH-continuing) PALISADE participants who tolerated 300-mg peanut protein at the exit double-blind placebo-controlled food challenge and placebo arm (PTAH-naive) participants could enter ARC004. PTAH-continuing participants were assigned to receive daily (cohorts 1 and 3A) or non-daily (cohorts 2, 3B, and 3C) dosing regimens; PTAH-naive participants were built up to 300 mg/d PTAH, followed by maintenance dosing. At study completion, participants underwent an exit double-blind placebo-controlled food challenge with doses up to 2000 mg peanut protein. Data were assessed using descriptive statistics. RESULTS: Overall, 358 (87.5%) eligible participants (4-17 years) entered ARC004 (PTAH-continuing, n = 256; PTAH-naive, n = 102). Among PTAH-continuing participants, exposure-adjusted adverse event rates were 12.94 to 17.54/participant-year and 25.95 to 42.49/participant-year in daily and non-daily dosing cohorts, respectively; most participants (83%) experienced mild or moderate adverse events. Daily dosing cohorts appeared to have higher desensitization rates than non-daily dosing cohorts. Of all PTAH-continuing cohorts, cohort 3A had the longest daily dosing duration and the highest desensitization rates. Changes in immune markers with PTAH continuation demonstrated ongoing immunomodulation. Outcomes in PTAH-naive participants mirrored those of the PALISADE active arm. CONCLUSIONS: Continued daily PTAH treatment beyond 1 year showed sustained safety and efficacy. Ongoing immunomodulation was observed during the second year of treatment.

Infections in Infants with SCID: Isolation, Infection Screening, and Prophylaxis in PIDTC Centers.

PURPOSE: The Primary Immune Deficiency Treatment Consortium (PIDTC) enrolled children with severe combined immunodeficiency (SCID) in a prospective natural history study of hematopoietic stem cell transplant (HSCT) outcomes over the last decade. Despite newborn screening (NBS) for SCID, infections occurred prior to HSCT. This study's objectives were to define the types and timing of infection prior to HSCT in patients diagnosed via NBS or by family history (FH) and to understand the breadth of strategies employed at PIDTC centers for infection prevention. METHODS: We analyzed retrospective data on infections and pre-transplant management in patients with SCID diagnosed by NBS and/or FH and treated with HSCT between 2010 and 2014. PIDTC centers were surveyed in 2018 to understand their practices and protocols for pre-HSCT management. RESULTS: Infections were more common in patients diagnosed via NBS (55%) versus those diagnosed via FH (19%) (p = 0.012). Outpatient versus inpatient management did not impact infections (47% vs 35%, respectively; p = 0.423). There was no consensus among PIDTC survey respondents as to the best setting (inpatient vs outpatient) for pre-HSCT management. While isolation practices varied, immunoglobulin replacement and antimicrobial prophylaxis were more uniformly implemented. CONCLUSION: Infants with SCID diagnosed due to FH had lower rates of infection and proceeded to HSCT more quickly than did those diagnosed via NBS. Pre-HSCT management practices were highly variable between centers, although uses of prophylaxis and immunoglobulin support were more consistent. This study demonstrates a critical need for development of evidence-based guidelines for the pre-HSCT management of infants with SCID following an abnormal NBS. TRIAL REGISTRATION: NCT01186913.

Unknown cytomegalovirus serostatus in primary immunodeficiency disorders: A new category of transplant recipients.

BACKGROUND: Cytomegalovirus (CMV) serostatus of recipient (R) and donor (D) influences hematopoietic stem cell transplant (HSCT) outcome. However, it is not a reliable indicator of CMV infection in primary immunodeficiency disorder (PIDD) recipients who are unable to make adequate antigen-specific immunoglobulin (Ig) or who receive intravenous Ig (IVIg) prior to testing. OBJECTIVE: Since no data exist on PIDD with unknown CMV serostatus, we aimed to evaluate the relationship between pre-HSCT recipient and donor serostatus and incidence of CMV infection in recipients with unknown serostatus. METHODS: A retrospective analysis of all pediatric PIDD HSCTs (2007-2018) was performed at University of California San Francisco. Recipients were separated into categories based on pre-transplant serostatus: 1) seropositive (R(+)), 2) seronegative (R(-)), and 3) unknown serostatus (R(x)). Patients with pre-HSCT active CMV viremia were excluded. RESULTS: A total of 90 patients were included, 69% male. The overall incidence of CMV infection was 20%, but varied in R(+), R(-), and R(x) at 80%, 0%, and 14%, (P-value = .0001). Similarly, 5-year survival differed among groups, 60% R(+), 100% R(-), and 90% of R(x) (P-value = .0045). There was no difference in CMV reactivation by donor serostatus (P-value = .29), however, faster time to clearance of CMV was observed for R(x)/D(+) group (median 9.5 days (IQR 2.5-18), P-value = .024). CONCLUSION: We identify a novel group of recipients, R(x), with an intermediate level of survival and CMV incidence post-HSCT, when compared to seropositive and seronegative recipients. No evidence of CMV transmission from D(+) in R(-) and R(x) was observed. We believe R(x) should be considered as a separate category in future studies to better delineate recipient risk status.

Folliculotropic mycosis fungoides driven by DOCK8 immunodeficiency syndrome.

DOCK8 immunodeficiency syndrome (DIDS) represents a rare primary immunodeficiency associated with cutaneous viral infections, allergy, and increased risk of malignancy. We report a case of folliculotropic mycosis fungoides with spontaneous resolution occurring in a patient with DIDS.

Transfer of monoclonal antibodies into breastmilk in neurologic and non-neurologic diseases.

OBJECTIVE: To review currently available data on the transfer of monoclonal antibodies (mAbs) in the breastmilk of women receiving treatment for neurologic and non-neurologic diseases. METHODS: We systematically searched the medical literature for studies referring to 19 selected mAb therapies frequently used in neurologic conditions and "breastmilk," "breast milk," "breastfeeding," or "lactation." From an initial list of 288 unique references, 29 distinct full-text studies met the eligibility criteria. One additional study was added after the literature search based on expert knowledge of an additional article. These 30 studies were reviewed. These assessed the presence of our selected mAbs in human breastmilk in samples collected from a total of 155 individual women. RESULTS: Drug concentrations were typically low in breastmilk and tended to peak within 48 hours, although maximum levels could occur up to 14 days from infusion. Most studies did not evaluate the breastmilk to maternal serum drug concentration ratio, but in those evaluating this, the highest ratio was 1:20 for infliximab. Relative infant dose, a metric comparing the infant with maternal drug dose (<10% is generally considered safe), was evaluated for certolizumab (<1%), rituximab (<1%), and natalizumab (maximum of 5.3%; cumulative effects of monthly dosing are anticipated). Importantly, a total of 368 infants were followed for ≥6 months after exposure to breastmilk of mothers treated with mAbs; none experienced reported developmental delay or serious infections. CONCLUSIONS: The current data are reassuring for low mAb drug transfer to breastmilk, but further studies are needed, including of longer-term effects on infant immunity and childhood development.

Lentiviral gene therapy for X-linked chronic granulomatous disease.

Chronic granulomatous disease (CGD) is a rare inherited disorder of phagocytic cells1,2. We report the initial results of nine severely affected X-linked CGD (X-CGD) patients who received ex vivo autologous CD34+ hematopoietic stem and progenitor cell-based lentiviral gene therapy following myeloablative conditioning in first-in-human studies (trial registry nos. NCT02234934 and NCT01855685). The primary objectives were to assess the safety and evaluate the efficacy and stability of biochemical and functional reconstitution in the progeny of engrafted cells at 12 months. The secondary objectives included the evaluation of augmented immunity against bacterial and fungal infection, as well as assessment of hematopoietic stem cell transduction and engraftment. Two enrolled patients died within 3 months of treatment from pre-existing comorbidities. At 12 months, six of the seven surviving patients demonstrated stable vector copy numbers (0.4-1.8 copies per neutrophil) and the persistence of 16-46% oxidase-positive neutrophils. There was no molecular evidence of either clonal dysregulation or transgene silencing. Surviving patients have had no new CGD-related infections, and six have been able to discontinue CGD-related antibiotic prophylaxis. The primary objective was met in six of the nine patients at 12 months follow-up, suggesting that autologous gene therapy is a promising approach for CGD patients.