Trends in intravenous immunoglobulin use in New South Wales, Australia.

BACKGROUND: Intravenous immunoglobulin (IVIg) is a critical replacement therapy for immunodeficiencies and immunomodulatory treatment for autoimmune and inflammatory diseases. Adequate supply of IVIg is a global issue, necessitating supply restrictions. In Australia, despite strict criteria for use, demand for IVIg has increased over time and exceeds domestic supply. OBJECTIVE: Factors associated with the upward trend in overall IVIg use were examined, including in the number of unique patients, IVIg dosing and treatment frequency and variations by prescribing discipline and disease group. METHODS: De-identified data of IVIg dispensed in the largest Australian state (New South Wales) from 2007 to 2013 were provided by Australian Red Cross Lifeblood. Trends and projections were calculated using log-linear regression of unique patients, treatment episodes and grams of IVIg for overall use and use stratified by discipline and disease group. RESULTS: During the study period, 169 453 treatment episodes were recorded for 12 547 unique patients accounting for 5 827 787 g of IVIg use. Overall, IVIg use increased by 12.0% (11.5-12.6%) per year representing a 97.7% increase (91.6-104%) over the study period. The highest growth was among neurological conditions (16.0% (14.9-17.1%) per year). An increase in the number of unique patients was the primary driver of this growth, augmented by increases in the frequency and average dose per treatment. CONCLUSIONS: Clinically acceptable measures to improve management of IVIg supply are needed including optimising dose, frequency and duration of treatment. Formal evaluation of IVIg versus alternatives, including cost-effectiveness and comparative efficacy, is warranted.

Advances and Challenges of the Decade: The Ever-Changing Clinical and Genetic Landscape of Immunodeficiency.

In the past 10 years, we have witnessed major advances in clinical immunology. Newborn screening for severe combined immunodeficiency has become universal in the United States and screening programs are being extended to severe combined immunodeficiency and other inborn errors of immunity globally. Early genetic testing is becoming the norm for many of our patients and allows for informed selection of targeted therapies including biologics repurposed from other specialties. During the COVID-19 pandemic, our understanding of essential immune responses expanded and the discovery of immune gene defects continued. Immunoglobulin products, the backbone of protection for antibody deficiency syndromes, came into use to minimize side effects. New polyclonal and monoclonal antibody products emerged with increasing options to manage respiratory viral agents such as SARS-CoV-2 and respiratory syncytial virus. Against these advances, we still face major challenges. Atypical is becoming typical as phenotypes of distinct genetic disease overlap whereas the clinical spectrum of the same genetic defect widens. Therefore, clinical judgment needs to be paired with repeated deep immune phenotyping and upfront genetic testing, as technologies rapidly evolve, and clinical disease often progresses with age. Managing patients with organ damage resulting from immune dysregulation poses a special major clinical challenge and management often lacks standardization, from autoimmune cytopenias, granulomatous interstitial lung disease, enteropathy, and liver disease to endocrine, rheumatologic, and neurologic complications. Clinical, translational, and basic science networks will continue to advance the field; however, cross-talk and education with practicing allergists/immunologists are essential to keep up with the ever-changing clinical and genetic landscape of inborn errors of immunity.

SAMD9L autoinflammatory or ataxia pancytopenia disease mutations activate cell-autonomous translational repression.

Sterile α motif domain-containing protein 9-like (SAMD9L) is encoded by a hallmark interferon-induced gene with a role in controlling virus replication that is not well understood. Here, we analyze SAMD9L function from the perspective of human mutations causing neonatal-onset severe autoinflammatory disease. Whole-genome sequencing of two children with leukocytoclastic panniculitis, basal ganglia calcifications, raised blood inflammatory markers, neutrophilia, anemia, thrombocytopaenia, and almost no B cells revealed heterozygous de novo SAMD9L mutations, p.Asn885Thrfs*6 and p.Lys878Serfs*13. These frameshift mutations truncate the SAMD9L protein within a domain a region of homology to the nucleotide-binding and oligomerization domain (NOD) of APAF1, ∼80 amino acids C-terminal to the Walker B motif. Single-cell analysis of human cells expressing green fluorescent protein (GFP)-SAMD9L fusion proteins revealed that enforced expression of wild-type SAMD9L repressed translation of red fluorescent protein messenger RNA and globally repressed endogenous protein translation, cell autonomously and in proportion to the level of GFP-SAMD9L in each cell. The children's truncating mutations dramatically exaggerated translational repression even at low levels of GFP-SAMD9L per cell, as did a missense Arg986Cys mutation reported recurrently as causing ataxia pancytopenia syndrome. Autoinflammatory disease associated with SAMD9L truncating mutations appears to result from an interferon-induced translational repressor whose activity goes unchecked by the loss of C-terminal domains that may normally sense virus infection.

Somatic reversion of pathogenic DOCK8 variants alters lymphocyte differentiation and function to effectively cure DOCK8 deficiency.

Inborn errors of immunity cause monogenic immune dysregulatory conditions such as severe and recurrent pathogen infection, inflammation, allergy, and malignancy. Somatic reversion refers to the spontaneous repair of a pathogenic germline genetic variant and has been reported to occur in a number of inborn errors of immunity, with a range of impacts on clinical outcomes of these conditions. DOCK8 deficiency due to biallelic inactivating mutations in DOCK8 causes a combined immunodeficiency characterized by severe bacterial, viral, and fungal infections, as well as allergic disease and some cancers. Here, we describe the clinical, genetic, and cellular features of 3 patients with biallelic DOCK8 variants who, following somatic reversion in multiple lymphocyte subsets, exhibited improved clinical features, including complete resolution of infection and allergic disease, and cure over time. Acquisition of DOCK8 expression restored defective lymphocyte signalling, survival and proliferation, as well as CD8+ T cell cytotoxicity, CD4+ T cell cytokine production, and memory B cell generation compared with typical DOCK8-deficient patients. Our temporal analysis of DOCK8-revertant and DOCK8-deficient cells within the same individual established mechanisms of clinical improvement in these patients following somatic reversion and revealed further nonredundant functions of DOCK8 in human lymphocyte biology. Last, our findings have significant implications for future therapeutic options for the treatment of DOCK8 deficiency.

Molecular Analysis of Goodpasture's Disease Following Hematopoietic Stem Cell Transplant in a Pediatric Patient, Recalls the Conformeropathy of Wild-Type Anti-GBM Disease.

Background: Goodpasture's disease (GP) is mediated by autoantibodies that bind the glomerular and alveolar basement membrane, causing rapidly progressive glomerulonephritis with or without pulmonary hemorrhage. The autoantibodies bind neoepitopes formed upon disruption of the quaternary structure of α345NC1 hexamer, a critical structural domain of α345 collagen IV scaffolds. Hexamer disruption leads to a conformational changes that transitions α3 and α5NC1 subunits into immunogens, however, the trigger remains unknown. This contrasts with another anti-GBM disease, Alports' post-transplant nephritis (APTN), where the pathogenic alloantibody binds directly to native NC1 hexamer. The current report includes the first study of antigenic specificity and allo-incompatability in anti-GBM disease occurring after allogeneic haematopoietic stem cell transplant (HSCT). Results: The anti-GBM antibodies were found to be directed predominantly against the EA epitope of the α3 NC1 monomer of collagen IV and developed rapidly in patient serum reaching peak level within 5 weeks. Autoantibody binding to native α345NC1 hexamer was minimal; however, binding was greatly increased upon dissociation of the native hexamer. There were no polymorphic genetic differences between donor and recipient collagen IV genes which would be predicted to cause a significant NC1 conformational change or to provide a target for antibody binding. Both patient and donor possessed the Goodpasture's susceptibility HLA-allele DRB1*1501. Conclusions: The current report includes the first in-depth study of allo-incompatability and antigenic specificity in anti-GBM disease occurring after allogeneic haematopoietic stem cell transplant (HSCT). No polymorphic genetic differences were identified between donor and recipient collagen IV genes which would be predicted to provide a target for antibody binding. Furthermore, autoantibody binding to native α345NC1 hexamer was minimal, increasing greatly upon dissociation of the native hexamer, resembling wild-type GP diseases and marking this as the first example of a post-HSCT conformeropathy.

Denisovan, modern human and mouse TNFAIP3 alleles tune A20 phosphorylation and immunity.

Resisting and tolerating microbes are alternative strategies to survive infection, but little is known about the evolutionary mechanisms controlling this balance. Here genomic analyses of anatomically modern humans, extinct Denisovan hominins and mice revealed a TNFAIP3 allelic series with alterations in the encoded immune response inhibitor A20. Each TNFAIP3 allele encoded substitutions at non-catalytic residues of the ubiquitin protease OTU domain that diminished IκB kinase-dependent phosphorylation and activation of A20. Two TNFAIP3 alleles encoding A20 proteins with partial phosphorylation deficits seemed to be beneficial by increasing immunity without causing spontaneous inflammatory disease: A20 T108A;I207L, originating in Denisovans and introgressed in modern humans throughout Oceania, and A20 I325N, from an N-ethyl-N-nitrosourea (ENU)-mutagenized mouse strain. By contrast, a rare human TNFAIP3 allele encoding an A20 protein with 95% loss of phosphorylation, C243Y, caused spontaneous inflammatory disease in humans and mice. Analysis of the partial-phosphorylation A20 I325N allele in mice revealed diminished tolerance of bacterial lipopolysaccharide and poxvirus inoculation as tradeoffs for enhanced immunity.

Immunogenicity and Safety of a Quadrivalent Meningococcal ACWY-tetanus Toxoid Conjugate Vaccine 6 Years After MenC Priming as Toddlers.

BACKGROUND: We assessed immunogenicity, antibody persistence and safety of the meningococcal serogroups A, C, W and Y-tetanus toxoid (TT) conjugate vaccine (MenACWY-TT) in children primed as toddlers with MenC vaccine. METHODS: This open, multicenter extension study enrolled children 84-95 months of age who had received one dose of the combined Haemophilus influenzae type b (Hib)-MenC-TT conjugate vaccine (HibMenC group) or Hib-TT and monovalent MenC (MCC)-CRM197 vaccines (Hib+MCC group) at 12-18 months of age, in the primary study. All participants received one dose of MenACWY-TT. We assessed immunogenicity against MenA, MenC, MenW and MenY at 1 month and 2 years postvaccination by serum bactericidal assay using baby rabbit complement (rSBA). Safety and reactogenicity were evaluated. RESULTS: Six years post-MenC vaccination, <20% of children retained rSBA-MenC titers ≥1:8. At 1 month post-MenACWY-TT vaccination, vaccine response rates against all serogroups were high for both groups with ≥97.1% of children having rSBA ≥1:8. Two years postvaccination, ≥63.6% of children retained rSBA-MenA ≥1:8, and ≥87.9% for other serogroups. Geometric mean titers for all serogroups declined at 2 years post-MenACWY-TT vaccination, but remained ≥13 times higher than prevaccination levels. For both groups, pain (≤58.5%), redness (≤51.4%) and fatigue (≤27.0%) were the most frequently reported adverse events. No serious adverse events were reported. CONCLUSIONS: One dose of MenACWY-TT boosts protection against MenC in primed children, is safe and extends protection against MenA, MenW and MenY. Immunogenicity and safety were comparable in infants vaccinated with conjugated vaccine (HibMenC-TT) or the separate vaccines (Hib-TT and MCC-CRM197).

Hematopoietic stem cell transplant effectively rescues lymphocyte differentiation and function in DOCK8-deficient patients.

Bi-allelic inactivating mutations in DOCK8 cause a combined immunodeficiency characterised by severe pathogen infections, eczema, allergies, malignancy and impaired humoral responses. These clinical features result from functional defects in most lymphocyte lineages. Thus, DOCK8 plays a key role in immune cell function. Hematopoietic stem cell transplantation (HSCT) is curative for DOCK8 deficiency. While previous reports have described clinical outcomes for DOCK8 deficiency following HSCT, the effect on lymphocyte reconstitution and function has not been investigated. Our study determined whether defects in lymphocyte differentiation and function in DOCK8-deficient patients were restored following HSCT. DOCK8-deficient T and B lymphocytes exhibited aberrant activation and effector function in vivo and in vitro. Frequencies of αß T and MAIT cells were reduced while γδT cells were increased in DOCK8-deficient patients. HSCT improved, abnormal lymphocyte function in DOCK8-deficient patients. Elevated total and allergen-specific IgE in DOCK8-deficient patients decreased over time following HSCT. Our results document the extensive catalogue of cellular defects in DOCK8-deficient patients, and the efficacy of HSCT to correct these defects, concurrent with improvements in clinical phenotypes. Overall, our findings provide mechanisms at a functional cellular level for improvements in clinical features of DOCK8 deficiency post-HSCT, identify biomarkers that correlate with improved clinical outcomes, and inform the general dynamics of immune reconstitution in patients with monogenic immune disorders following HSCT.

Hematopoietic Stem Cell Transplantation as Treatment for Patients with DOCK8 Deficiency.

BACKGROUND: Biallelic variations in the dedicator of cytokinesis 8 (DOCK8) gene cause a combined immunodeficiency with eczema, recurrent bacterial and viral infections, and malignancy. Natural disease outcome is dismal, but allogeneic hematopoietic stem cell transplantation (HSCT) can cure the disease. OBJECTIVE: To determine outcome of HSCT for DOCK8 deficiency and define possible outcome variables. METHODS: We performed a retrospective study of the results of HSCT in a large international cohort of DOCK8-deficient patients. RESULTS: We identified 81 patients from 22 centers transplanted at a median age of 9.7 years (range, 0.7-27.2 years) between 1995 and 2015. After median follow-up of 26 months (range, 3-135 months), 68 (84%) patients are alive. Severe acute (III-IV) or chronic graft versus host disease occurred in 11% and 10%, respectively. Causes of death were infections (n = 5), graft versus host disease (5), multiorgan failure (2), and preexistent lymphoma (1). Survival after matched related (n = 40) or unrelated (35) HSCT was 89% and 81%, respectively. Reduced-toxicity conditioning based on either treosulfan or reduced-dose busulfan resulted in superior survival compared with fully myeloablative busulfan-based regimens (97% vs 78%; P = .049). Ninety-six percent of patients younger than 8 years at HSCT survived, compared with 78% of those 8 years and older (P = .06). Of the 73 patients with chimerism data available, 65 (89%) had more than 90% donor T-cell chimerism at last follow-up. Not all disease manifestations responded equally well to HSCT: eczema, infections, and mollusca resolved quicker than food allergies or failure to thrive. CONCLUSIONS: HSCT is curative in most DOCK8-deficient patients, confirming this approach as the treatment of choice. HSCT using a reduced-toxicity regimen may offer the best chance for survival.

A novel nucleotide oligomerisation domain 2 mutation in a family with Blau syndrome: Phenotype and function.

Mutations in the nucleotide binding domain of the PRR, NOD2, are associated with the autoinflammatory diseases Blau syndrome and early-onset sarcoidosis. Current theories suggest that constitutive activation of the NOD2 pathway may be responsible for pathogenesis of these diseases. Here, we report the phenotype of a kindred with Blau syndrome caused by a novel NOD2 mutation (p.E383D). Signaling protein and cytokine expression were examined, and the results of these experiments challenge current theories of constitutive NOD2 activation in the pathophysiology of Blau syndrome.

Haematopoietic stem cell transplantation for primary immunodeficiency syndromes: A 5-year single-centre experience.

AIM: Haematopoietic stem cell transplantation (HSCT) is a central therapy in the treatment of primary immunodeficiency diseases (PIDs). Over the past 5 years, outcomes have been greatly improved due to earlier diagnosis, improved donor availability, advancements in graft manipulation and the use of less toxic preparative regimens. We present a 5-year audit of HSCT for PID at a single Australian tertiary hospital. METHODS: Retrospective case note review identified diagnosis, pre-transplant medical morbidity, transplant protocol, engraftment, adverse events, post-transplant immune reconstitution and general health. RESULTS: A total of 22 patients with PID underwent 24 HSCTs at our institution between 2012 and 2016. The most common indications were severe combined immunodeficiency, chronic granulomatous disease and familial haemophagocytic lymphohistiocytosis, with a genetic diagnosis in all but two patients. Reduced intensity or reduced toxicity conditioning was used in 91% of cases, and 75% of the donors were unrelated. Transplant-related mortality at day +100 was 9.5%, and cumulative overall survival was 86%. There were three mortalities, all secondary to viral infection, one of which occurred in the context of graft failure. Two patients remained on immune support, with the remainder achieving adequate immune reconstitution. CONCLUSIONS: The outcomes for HSCT for PIDs performed at Sydney Children's Hospital were in line with the world's best practice. HSCT should be considered a potential therapeutic option for all Australian PID patients with a valid disease indication.

Haematopoietic stem cell transplantation for severe combined immunodeficiency: Long-term health outcomes and patient perspectives.

AIM: To examine the long-term follow-up and health outcomes of patients who have undergone haematopoietic stem cell transplant (HSCT) for severe combined immunodeficiency (SCID). METHODS: Through a structured questionnaire, we examined follow-up arrangements and long-term health outcomes in 22 children who have had a successful HSCT for SCID during the period of 1984-2012 at the Sydney Children's Hospital, Sydney, Australia. RESULTS: Most children considered themselves healthy and 'cured' from SCID. Whilst many children enjoy relatively good bio-social health outcomes, specific negative health outcomes and absenteeism from school were perceived negatively. Two-thirds of children see their general practitioner or specialist regularly; however, there did not appear to be consistency with the nature of this follow-up. CONCLUSION: The findings from our study highlight the complex bio-psychosocial health needs of post-HSCT SCID children and encourage SCID centres to consider a multidisciplinary approach to their follow-up. Further studies into the determinants of patients' perceptions of their health are needed.

Early infant male circumcision: Systematic review, risk-benefit analysis, and progress in policy.

AIM: To determine whether recent evidence-based United States policies on male circumcision (MC) apply to comparable Anglophone countries, Australia and New Zealand. METHODS: Articles in 2005 through 2015 were retrieved from PubMed using the keyword "circumcision" together with 36 relevant subtopics. A further PubMed search was performed for articles published in 2016. Searches of the EMBASE and Cochrane databases did not yield additional citable articles. Articles were assessed for quality and those rated 2+ and above according to the Scottish Intercollegiate Grading System were studied further. The most relevant and representative of the topic were included. Bibliographies were examined to retrieve further key references. Randomized controlled trials, recent high quality systematic reviews or meta-analyses (level 1++ or 1+ evidence) were prioritized for inclusion. A risk-benefit analysis of articles rated for quality was performed. For efficiency and reliability, recent randomized controlled trials, meta-analyses, high quality systematic reviews and large well-designed studies were used if available. Internet searches were conducted for other relevant information, including policies and Australian data on claims under Medicare for MC. RESULTS: Evidence-based policy statements by the American Academy of Pediatrics (AAP) and the Centers for Disease Control and Prevention (CDC) support infant and later age male circumcision (MC) as a desirable public health measure. Our systematic review of relevant literature over the past decade yielded 140 journal articles that met our inclusion criteria. Together, these showed that early infant MC confers immediate and lifelong benefits by protecting against urinary tract infections having potential adverse long-term renal effects, phimosis that causes difficult and painful erections and "ballooning" during urination, inflammatory skin conditions, inferior penile hygiene, candidiasis, various sexually transmissible infections in both sexes, genital ulcers, and penile, prostate and cervical cancer. Our risk-benefit analysis showed that benefits exceeded procedural risks, which are predominantly minor, by up to 200 to 1. We estimated that more than 1 in 2 uncircumcised males will experience an adverse foreskin-related medical condition over their lifetime. Wide-ranging evidence from surveys, physiological measurements, and the anatomical location of penile sensory receptors responsible for sexual sensation strongly and consistently suggested that MC has no detrimental effect on sexual function, sensitivity or pleasure. United States studies showed that early infant MC is cost saving. The evidence supporting early infant MC has further strengthened since the positive AAP and CDC reviews. CONCLUSION: Affirmative MC policies are needed in Australia and New Zealand. Routine provision of accurate, unbiased education, and access in public hospitals, will maximize health and financial benefits.

Dedicator of cytokinesis 8-deficient CD4+ T cells are biased to a TH2 effector fate at the expense of TH1 and TH17 cells.

BACKGROUND: Dedicator of cytokinesis 8 (DOCK8) deficiency is a combined immunodeficiency caused by autosomal recessive loss-of-function mutations in DOCK8. This disorder is characterized by recurrent cutaneous infections, increased serum IgE levels, and severe atopic disease, including food-induced anaphylaxis. However, the contribution of defects in CD4+ T cells to disease pathogenesis in these patients has not been thoroughly investigated. OBJECTIVE: We sought to investigate the phenotype and function of DOCK8-deficient CD4+ T cells to determine (1) intrinsic and extrinsic CD4+ T-cell defects and (2) how defects account for the clinical features of DOCK8 deficiency. METHODS: We performed in-depth analysis of the CD4+ T-cell compartment of DOCK8-deficient patients. We enumerated subsets of CD4+ T helper cells and assessed cytokine production and transcription factor expression. Finally, we determined the levels of IgE specific for staple foods and house dust mite allergens in DOCK8-deficient patients and healthy control subjects. RESULTS: DOCK8-deficient memory CD4+ T cells were biased toward a TH2 type, and this was at the expense of TH1 and TH17 cells. In vitro polarization of DOCK8-deficient naive CD4+ T cells revealed the TH2 bias and TH17 defect to be T-cell intrinsic. Examination of allergen-specific IgE revealed plasma IgE from DOCK8-deficient patients is directed against staple food antigens but not house dust mites. CONCLUSION: Investigations into the DOCK8-deficient CD4+ T cells provided an explanation for some of the clinical features of this disorder: the TH2 bias is likely to contribute to atopic disease, whereas defects in TH1 and TH17 cells compromise antiviral and antifungal immunity, respectively, explaining the infectious susceptibility of DOCK8-deficient patients.

Mevalonate kinase deficiency leads to decreased prenylation of Rab GTPases.

Mevalonate kinase deficiency (MKD) is caused by mutations in a key enzyme of the mevalonate-cholesterol biosynthesis pathway, leading to recurrent autoinflammatory disease characterised by enhanced release of interleukin-1ß (IL-1ß). It is currently believed that the inflammatory phenotype of MKD is triggered by temperature-sensitive loss of mevalonate kinase activity and reduced biosynthesis of isoprenoid lipids required for the prenylation of small GTPase proteins. However, previous studies have not clearly shown any change in protein prenylation in patient cells under normal conditions. With lymphoblast cell lines from two compound heterozygous MKD patients, we used a highly sensitive in vitro prenylation assay, together with quantitative mass spectrometry, to reveal a subtle accumulation of unprenylated Rab GTPases in cells cultured for 3 days or more at 40 °C compared with 37 °C. This included a 200% increase in unprenylated Rab7A, Rab14 and Rab1A. Inhibition of sterol regulatory element-binding protein (SREBP) activation by fatostatin led to more pronounced accumulation of unprenylated Rab proteins in MKD cells but not parent cells, suggesting that cultured MKD cells may partially overcome the loss of isoprenoid lipids by SREBP-mediated upregulation of enzymes required for isoprenoid biosynthesis. Furthermore, while inhibition of Rho/Rac/Rap prenylation promoted the release of IL-1ß, specific inhibition of Rab prenylation by NE10790 had no effect in human peripheral blood mononuclear cells or human THP-1 monocytic cells. These studies demonstrate for the first time that mutations in mevalonate kinase can lead to a mild, temperature-induced defect in the prenylation of small GTPases, but that loss of prenylated Rab GTPases is not the cause of enhanced IL-1ß release in MKD.