Primary Immune Regulatory Disorders Research Articles

Transplantation for immune dysregulatory disorders: current themes and future expectations.

Primary immune regulatory disorders (PIRDs) are an increasing indication for hematopoietic stem cell transplant (HCT) in pediatric patients. Here, we provide an updated overview of HCT for PIRDs, and discuss future avenues for improvement in outcomes. There are now more than 50 described monogenic PIRDs, which impact all aspects of immune tolerance, regulation, and suppression. Disease characteristics are highly variable, and HCT remains the only option for cure. We review advances in targeted therapies for individual PIRDs, which have significantly improved outcomes and the ability to safely bridge to transplant. Additionally, advances in GVHD prevention, graft manipulation, personalized conditioning regimens, and supportive care have all increased survival after HCT. The high inflammatory state increases the risk of nonengraftment, rejection, and autologous reconstitution. Therapy to reduce the inflammatory state may further improve outcomes. In addition, although younger patients with fewer comorbidities have better outcomes, the clinical courses of these diseases may be extremely variable thereby complicating the decision to proceed to HCT. HCT for PIRDs is a growing consideration in cell therapy. Yet, there remain significant gaps in our understanding of which patients this curative therapy could benefit the most. Here, we review the current data supporting HCT for PIRDs as well as areas for future improvement.

Immunodeficiency: Overview of primary immune regulatory disorders (PIRDs).

Primary immune regulatory disorders (PIRD) comprise a heterogeneous group of monogenic disorders that impact homeostatic control of inflammation and immune tolerance. Patients with a PIRD typically present to medical care with symptoms of autoimmunity or hyperinflammation as the dominant clinical feature, symptoms that include fever, rash, lymphadenopathy, organomegaly, arthritis, and colitis are commonplace. Notably, PIRDs are a distinct entity from primary immune deficiency disorders (PIDD), which are primarily defined by a qualitative or quantitative defect in immunity, which manifests as a susceptibility to recurrent infections. PIDDs and PIRDs can be challenging to differentiate because the clinical presentations can be similar. Red flags for PIRDs include multiple autoimmune diagnoses in the same patient, chronic lymphadenopathy, hepatomegaly, and/or splenomegaly, chronic colitis, hemophagocytic lymphohistiocytosis (HLH), Epstein Barr virus (EBV) susceptibility, recurrent or persistent fever, vasculitis, and sterile inflammation. For simplicity in this brief review, we limit our discussion of PIRDs to the following categories multiple autoimmune diseases, immune dysregulation with colitis, disorders with HLH and/or EBV susceptibility, autoinflammatory syndromes, type 1 interferonopathies, and disorders of sterile inflammation. Diagnosing a PIRD requires a broad immune evaluation for both immune system deficiencies and inflammation, along with genetic testing. Given the complex nature of these diseases, treatment often requires a team of subspecialists. Treatment, depending on the specific diagnosis, may be somewhat empiric with nonspecific immune modulators, symptom-directed therapies, and, in severe cases, hematopoietic stem cell transplantation; however, with the increasing number of biologics available, we are often able to use targeted immune therapy or even gene therapy.

Targeted treatments for immune dysregulation in inborn errors of immunity

Primary immune regulatory disorders (PIRDs) constitute a subset of inborn errors of immunity and are characterized by lymphoproliferation, autoimmunity, malignancy, and infection. Unlike classical primary immune deficiencies, initial symptoms of PIRDs can manifest as autoimmunity such as cytopenias or enteropathy, which can often prove resistant to conventional treatments and occur years prior to the onset of infectious complications. Raising awareness about PIRDs among specialists and adopting a multidisciplinary approach is crucial for early diagnosis, intervention, and potential prevention of severe organ damage. Significant progress has been made in identifying several PIRDs, which has contributed to a more comprehensive comprehension of their underlying immunological mechanisms. This knowledge has paved the way for targeted therapies focusing on specific molecules, which tend to offer superior disease control compared to traditional immunosuppressants. This review, informed by the latest literature, explores prevalent PIRDs, detailing their clinical manifestations and recent advancements in treatment modalities.

169 Long Term Management of Transplanted Patients with Chronic Granulomatous Disease, Wiskott-Aldrich Syndrome, and Primary Immune Regulatory Disorders: A PIDTC Survey

169 Long Term Management of Transplanted Patients with Chronic Granulomatous Disease, Wiskott-Aldrich Syndrome, and Primary Immune Regulatory Disorders: A PIDTC Survey

13 Long-Term Medical Management of Patients with Chronic Granulomatous Disease, Wiskott-Aldrich Syndrome, and Primary Immune Regulatory Disorders: A Primary Immune Deficiency Treatment Consortium Survey

13 Long-Term Medical Management of Patients with Chronic Granulomatous Disease, Wiskott-Aldrich Syndrome, and Primary Immune Regulatory Disorders: A Primary Immune Deficiency Treatment Consortium Survey

Primary immune regulatory disorders (PIRD): expanding the mutation spectrum in Turkey and identification of sixteen novel variants

Human Inborn Errors of Immunity (IEIs) encompass a clinically and genetically heterogeneous group of disorders, ranging from mild cases to severe, life-threatening types. Among these, Primary Immune Regulatory Disorders (PIRDs) constitute a subset of IEIs characterized by diverse clinical phenotypes, prominently featuring severe atopy, autoimmunity, lymphoproliferation, hyperinflammation, autoinflammation, and susceptibility to malignancies. According to the latest report from the International Union of Immunological Societies (IUIS), PIRDs arise from mutations in various genes including LYST, RAB27A, AP3B1, AP3D1, PRF1, UNC13D, STX11, STXBP2, FAAP24, SLC7A7, RASGRP1, CD70, CTPS1, RLTPR, ITK, MAGT1, PRKCD, TNFRSF9, SH2DIA, XIAP, CD27 (TNFRSF7), FAS (TNFRSF6), FASLG (TNFSF6), CASP10, CASP8, FADD, LRBA, STAT3, AIRE, ITCH, ZAP70, TPP2, JAK1, PEPD, FOXP3, IL2RA, CTLA4, BACH2, IL2RB, DEF6, FERMT1, IL10, IL10RA, IL10RB, NFAT5, TGFB1, and RIPK1 genes. We designed a targeted next-generation sequencing (TNGS) workflow using the Ion AmpliSeq™ Primary Immune Deficiency Research Panel to sequence 264 genes associated with IEIs on the Ion S5™ Sequencer. In this study, we report the identification of 38 disease-causing variants, including 16 novel ones, detected in 40 patients across 15 distinct PIRD genes. The application of next-generation sequencing enabled rapid and precise diagnosis of patients with PIRDs.

Infections in Disorders of Immune Regulation.

Primary immune regulatory disorders (PIRDs) constitute a spectrum of inborn errors of immunity (IEIs) that are primarily characterized by autoimmunity, lymphoproliferation, atopy, and malignancy. In PIRDs, infections are infrequent compared to other IEIs. While susceptibility to infection primarily stems from antibody deficiency, it is sometimes associated with additional innate immune and T or NK cell defects. The use of immunotherapy and chemotherapy further complicates the immune landscape, increasing the risk of diverse infections. Recurrent sinopulmonary infections, particularly bacterial infections such as those associated with staphylococcal and streptococcal organisms, are the most reported infectious manifestations. Predisposition to viral infections, especially Epstein-Barr virus (EBV)-inducing lymphoproliferation and malignancy, is also seen. Notably, mycobacterial and invasive fungal infections are rarely documented in these disorders. Knowledge about the spectrum of infections in these disorders would prevent diagnostic delays and prevent organ damage. This review delves into the infection profile specific to autoimmune lymphoproliferative syndrome (ALPS), Tregopathies, and syndromes with autoimmunity within the broader context of PIRD. Despite the critical importance of understanding the infectious aspects of these disorders, there remains a scarcity of comprehensive reports on this subject.

Primary Immune Regulatory Disorders (PIRDs) That Amplify mTOR Signaling Share a T Cell Exhaustion-like Process

Background: Primary Immune Regulatory Disorders (PIRDs) are a complex and challenging-to-treat subset of Inborn Errors of Immunity (IEI), which are characterized by immune dysregulation leading to recurrent infections, lymphoproliferation, and autoimmunity including refractory cytopenias. Since many ultra-rare monogenic PIRDs exist, it is not feasible to design targeted therapies for each. An alternate strategy is to identify shared aspects of T cell dysfunction and strategies targeting them. We have focused our studies on PIRDs that chronically amplify T cell receptor (TCR) signaling, mimicking chronic infection. Under conditions of chronic inflammation and antigen presentation, seen during chronic infections, CD8 T cell exhaustion (Tex) can result and is characterized by increased inhibitory receptor expression, altered transcriptional networks, epigenetic poise, and impaired T cell functions including cytokine production. Here, we have evaluated CD8 T cell dysfunction in PIRDs, including the potential for Tex. Methods: Deep immune phenotyping and T cell functional analyses were performed using CyTOF and spectral flow cytometry, in addition to single cell RNA-sequencing and CITE-seq from untreated PIRD and healthy control PBMCs. Finally, CRISPR/Cas9 editing in healthy control CD8 T cells was used to create a cellular disease model. Results: We identified a Tex-like process in activated PI3 kinase delta syndrome (APDS), CTLA-4 haploinsufficiency, and Ras-associated Autoimmune Leukoproliferative Disease (RALD), which share increased mTOR activation. We identified increased PD-1, CD39, TIGIT and TOX expression on CD8 T cells consistent with a Tex-like phenotype. We also found impaired CD8 T cell cytokine and proliferation consistent with Tex. Lastly, a cellular model of CTLA-4 haploinsufficiency was created for perturbation studies to evaluate best available therapies and target novel therapeutics in these rare disorders. Conclusion: By identifying shared patterns of CD8 T cell dysfunction in these ultra-rare disorders, we may both identify novel therapeutic strategies and increase our understanding of CD8 T cell function, including cytokine production.

Too much of a good thing: a review of primary immune regulatory disorders.

Primary immune regulatory disorders (PIRDs) are inborn errors of immunity caused by a loss in the regulatory mechanism of the inflammatory or immune response, leading to impaired immunological tolerance or an exuberant inflammatory response to various stimuli due to loss or gain of function mutations. Whilst PIRDs may feature susceptibility to recurrent, severe, or opportunistic infection in their phenotype, this group of syndromes has broadened the spectrum of disease caused by defects in immunity-related genes to include autoimmunity, autoinflammation, lymphoproliferation, malignancy, and allergy; increasing focus on PIRDs has thus redefined the classical 'primary immunodeficiency' as one aspect of an overarching group of inborn errors of immunity. The growing number of genetic defects associated with PIRDs has expanded our understanding of immune tolerance mechanisms and prompted identification of molecular targets for therapy. However, PIRDs remain difficult to recognize due to incomplete penetrance of their diverse phenotype, which may cross organ systems and present to multiple clinical specialists prior to review by an immunologist. Control of immune dysregulation with immunosuppressive therapies must be balanced against the enhanced infective risk posed by the underlying defect and accumulated end-organ damage, posing a challenge to clinicians. Whilst allogeneic hematopoietic stem cell transplantation may correct the underlying immune defect, identification of appropriate patients and timing of transplant is difficult. The relatively recent description of many PIRDs and rarity of individual genetic entities that comprise this group means data on natural history, clinical progression, and treatment are limited, and so international collaboration will be needed to better delineate phenotypes and the impact of existing and potential therapies. This review explores pathophysiology, clinical features, current therapeutic strategies for PIRDs including cellular platforms, and future directions for research.

Inborn Errors of Immunity and Autoimmune Disease.

Autoimmunity may be a manifestation of inborn errors of immunity (IEI) specifically as part of the subgroup of primary immunodeficiency (PID) known as primary immune regulatory disorders (PIRD). However, while making a single gene diagnosis can have important implications for prognosis and management, picking patients to screen can be difficult, against a background of a high prevalence of autoimmune disease in the population. This review compares the genetics of common polygenic and rare monogenic autoimmunity, and explores the molecular mechanisms, phenotypes and inheritance of autoimmunity associated with PIRD, highlighting the emerging importance of gain-of-function and non-germline somatic mutations. A novel framework for identifying rare monogenic cases of common diseases in children is presented, highlighting important clinical and immunological features that favor single gene disease and guides clinicians in selecting appropriate patients for genomic screening. Additionally, there will be a review of autoimmunity in non-genetically defined PID such as common variable immunodeficiency (CVID), and of instances where primary autoimmunity can result in clinical phenocopies of IEI.

Amplified STAT3 signaling alters expression of CD39 in STAT3 gain-of-function (STAT3 GOF) and in healthy donor CD8 +T cells

Abstract It is still unknown whether primary immune regulatory disorders (PIRD) due to genetic variants that amplify T cell receptor and/or inflammatory cytokine signaling yield T cell exhaustion. Here, we investigate the impact of dysregulated cytokine signaling on CD8 +T cells in STAT3 gain-of-function (STAT3 GOF) patients. Immune profiling via 43-parameter CyTOF reveals altered CD8 +T cell differentiation, including loss of naïve cells, increased frequency of effector memory and T EMRAcells, and downregulation of markers of stemness (i.e., TCF-1 and CD127) in STAT3 GOF. Additionally, STAT3 GOF CD8 +T cells demonstrate decreased IL-2 production and proliferation. We identify increased expression of the ecto-enzyme, CD39, which has been reported on exhausted cells and hydrolyzes extracellular ATP, on CD8 +T cells from STAT3 GOF patients and in a mouse model of STAT3 GOF. To identify the signals regulating CD39, healthy donor CD8 +T cells were cultured with STAT3-activating cytokines alone but did not upregulate CD39. However, TCR engagement led to robust CD39 expression which was further augmented with STAT3-activating cytokines. Specifically, CD39 upregulation occurs in pSTAT3 Y705+cells. Finally, sorted CD39 +CD8 +T cells hydrolyzed ATP and suppressed effector CD8 +T cell proliferation compared to CD39 −CD8 +T cells. These data suggest that STAT3 signaling may play a role in regulating CD39 levels and thus contribute to CD8 +T cell exhaustion, which will be explored in future work. Understanding how dysregulated STAT3 signaling impacts T cell function in these rare patients can improve our understanding of this complex disease and may yield insights into shared aspects of T cell dysfunction found in more common inflammatory diseases. HHMI Gilliam Fellowship for Advanced Studies (GT15736) Penn Presidential Fellowship PIDTC (Henrickson Lab) IDF (Henrickson Lab) NIH NIAD K08AI135091 (Henrickson Lab) Burroughs Wellcome Fund CAMS (Henrickson Lab)

What Mendel could learn from the inborn errors of immunity – harnessing the power of NGS genetic testing for diagnosis of immune disorders

The inborn errors of immunity (IEIs) include primary immunodeficiencies (PIDs) and primary immune regulatory disorders (PIRDs). Though there are somatic variations in genes that cause immunological disease, the IEIs, for the most part, describe germline gene defects. The IEIs now include 485 genes and the list continues to grow. These genes are classified into nine categories based on the component of the immune system dominantly affected (IUIS classification 2022). The explosion in the number of genes identified in the past two decades has to do with rapid advances in genomic technologies, which allow for high throughput analysis, such as next generation sequencing (NGS). NGS includes targeted gene panels (TGPs), exome (ES) and genome sequencing (GS), besides copy number variation (CNV) analysis. Since the etiological basis of most, if not all, IEIs is related to a single gene defect (monogenic) or in some cases, two genes (digenic), it stands to reason that diagnosis of these disorders requires genetic testing for confirmation of the diagnosis. However, a confirmed genetic answer is not just for diagnosis but also for selecting appropriate therapeutic and management strategies, which facilitates personalised approaches to treatment. This talk will provide an overview of the rationale for genetic testing for the diagnosis of IEIs, the most commonly used NGS methodologies and data analysis, which includes variant classification and interpretation of variants of uncertain significance (VUS). The talk will also provide information on various tools and databases used for genomic data analysis, and the concepts of incomplete penetrance, variable expressivity, somatic reversion, somatic mosaicism, hypopmoprhic variants, gain-of-function and loss-of-function.

A human STAT3 gain-of-function variant confers T cell dysregulation without predominant Treg dysfunction in mice.

Primary immune regulatory disorders (PIRD) represent a group of disorders characterized by immune dysregulation, presenting with a wide range of clinical disease, including autoimmunity, autoinflammation, or lymphoproliferation. Autosomal dominant germline gain-of-function (GOF) variants in STAT3 result in a PIRD with a broad clinical spectrum. Studies in patients have documented a decreased frequency of FOXP3+ Tregs and an increased frequency of Th17 cells in some patients with active disease. However, the mechanisms of disease pathogenesis in STAT3 GOF syndrome remain largely unknown, and treatment is challenging. We developed a knock-in mouse model harboring a de novo pathogenic human STAT3 variant (p.G421R) and found these mice developed T cell dysregulation, lymphoproliferation, and CD4+ Th1 cell skewing. Surprisingly, Treg numbers, phenotype, and function remained largely intact; however, mice had a selective deficiency in the generation of iTregs. In parallel, we performed single-cell RNA-Seq on T cells from STAT3 GOF patients. We demonstrate only minor changes in the Treg transcriptional signature and an expanded, effector CD8+ T cell population. Together, these findings suggest that Tregs are not the primary driver of disease and highlight the importance of preclinical models in the study of disease mechanisms in rare PIRD.

Defining and targeting patterns of T cell dysfunction in inborn errors of immunity.

Inborn errors of immunity (IEIs) are a group of more than 450 monogenic disorders that impair immune development and function. A subset of IEIs blend increased susceptibility to infection, autoimmunity, and malignancy and are known collectively as primary immune regulatory disorders (PIRDs). While many aspects of immune function are altered in PIRDs, one key impact is on T-cell function. By their nature, PIRDs provide unique insights into human T-cell signaling; alterations in individual signaling molecules tune downstream signaling pathways and effector function. Quantifying T-cell dysfunction in PIRDs and the underlying causative mechanisms is critical to identifying existing therapies and potential novel therapeutic targets to treat our rare patients and gain deeper insight into the basic mechanisms of T-cell function. Though there are many types of T-cell dysfunction, here we will focus on T-cell exhaustion, a key pathophysiological state. Exhaustion has been described in both human and mouse models of disease, where the chronic presence of antigen and inflammation (e.g., chronic infection or malignancy) induces a state of altered immune profile, transcriptional and epigenetic states, as well as impaired T-cell function. Since a subset of PIRDs amplify T-cell receptor (TCR) signaling and/or inflammatory cytokine signaling cascades, it is possible that they could induce T-cell exhaustion by genetically mimicking chronic infection. Here, we review the fundamentals of T-cell exhaustion and its possible role in IEIs in which genetic mutations mimic prolonged or amplified T-cell receptor and/or cytokine signaling. Given the potential insight from the many forms of PIRDs in understanding T-cell function and the challenges in obtaining primary cells from these rare disorders, we also discuss advances in CRISPR-Cas9 genome-editing technologies and potential applications to edit healthy donor T cells that could facilitate further study of mechanisms of immune dysfunctions in PIRDs. Editing T cells to match PIRD patient genetic variants will allow investigations into the mechanisms underpinning states of dysregulated T-cell function, including T-cell exhaustion.

Inborn Errors of Immunity With Fetal or Perinatal Clinical Manifestations.

In this article we revised the literature on Inborn Errors of Immunity (IEI) keeping our focus on those diseases presenting with intrauterine or perinatal clinical manifestations. We opted to describe our findings according to the IEI categories established by the International Union of Immunological Societies, predominantly addressing the immunological features of each condition or group of diseases. The main finding is that such precocious manifestations are largely concentrated in the group of primary immune regulatory disorders (PIRDs) and not in the group of classical immunodeficiencies. The IEI categories with higher number of immunological manifestations in utero or in perinatal period are: (i) diseases of immune dysregulation (HLH, IPEX and other Tregopathies, autosomal recessive ALPS with complete lack of FAS protein expression) and (ii) autoinflammatory diseases (NOMID/CINCA, DIRA and some interferonopathies, such as Aicardi-Goutières syndrome, AGS, and USP18 deficiency). Regarding the other IEI categories, some patients with Omenn syndrome (an atypical form of SCID), and a few X-linked CGD patients present with clinical manifestations at birth associated to immune dysregulation. The most frequent clinical features were hydrops fetalis, intrauterine growth retardation leading to fetal loss, stillbirths, and prematurity, as in HLH and IPEX. Additionally, pseudo-TORCH syndrome was observed in AGS and in USP18 deficiency. The main goal of our review was to contribute to increasing the medical awareness of IEI with intrauterine and perinatal onset, which has obvious implications for diagnosis, treatment, and genetic counseling.

Genetic diagnosis of immune dysregulation can lead to targeted therapy for interstitial lung disease: A case series and single center approach.

In recent years, a growing number of monogenic disorders have been described that are characterized by immune dysregulation. A subset of these "primary immune regulatory disorders" can cause severe interstitial lung disease, often recognized in late childhood or adolescence. Patients presenting to pulmonary clinic may have long and complex medical histories, but lack a unifying genetic diagnosis. It is crucial for pulmonologists to recognize features suggestive of multisystem immune dysregulation and to initiate genetic workup, since targeted therapies based on underlying genetics may halt or even reverse pulmonary disease progression. Through such an approach, our center has been able to diagnose and treat a cohort of patients with interstitial lung disease from gene defects that affect immune regulation. Here we present representative cases related to pathogenic variants in three distinct pathways and summarize disease manifestations and treatment approaches. We conclude with a discussion of our perspective on the outstanding challenges for diagnosing and managing these complex life-threatening and chronic disorders.

Autoimmune Cytopenias and Dysregulated Immunophenotype Act as Warning Signs of Inborn Errors of Immunity: Results From a Prospective Study

Inborn errors of immunity (IEI) are genetic disorders characterized by a wide spectrum of clinical manifestations, ranging from increased susceptibility to infections to significant immune dysregulation. Among these, primary immune regulatory disorders (PIRDs) are mainly presenting with autoimmune manifestations, and autoimmune cytopenias (AICs) can be the first clinical sign. Significantly, AICs in patients with IEI often fail to respond to first-line therapy. In pediatric patients, autoimmune cytopenias can be red flags for IEI. However, for these cases precise indicators or parameters useful to suspect and screen for a hidden congenital immune defect are lacking. Therefore, we focused on chronic/refractory AIC patients to perform an extensive clinical evaluation and multiparametric flow cytometry analysis to select patients in whom PIRD was strongly suspected as candidates for genetic analysis. Key IEI-associated alterations causative of STAT3 GOF disease, IKAROS haploinsufficiency, activated PI3Kδ syndrome (APDS), Kabuki syndrome and autoimmune lymphoproliferative syndrome (ALPS) were identified. In this scenario, a dysregulated immunophenotype acted as a potential screening tool for an early IEI diagnosis, pivotal for appropriate clinical management and for the identification of new therapeutic targets.

Hematopoietic stem cell transplantation for Inborn Errors of Immunity

Hematopoietic stem cell transplantation for Inborn Errors of Immunity

Primary Immune Regulatory Disorders With an Autoimmune Lymphoproliferative Syndrome-Like Phenotype: Immunologic Evaluation, Early Diagnosis and Management.

Primary immune regulatory disorders (PIRD) are associated with autoimmunity, autoinflammation and/or dysregulation of lymphocyte homeostasis. Autoimmune lymphoproliferative syndrome (ALPS) is a PIRD due to an apoptotic defect in Fas-FasL pathway and characterized by benign and chronic lymphoproliferation, autoimmunity and increased risk of lymphoma. Clinical manifestations and typical laboratory biomarkers of ALPS have also been found in patients with a gene defect out of the Fas-FasL pathway (ALPS-like disorders). Following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA), we identified more than 600 patients suffering from 24 distinct genetic defects described in the literature with an autoimmune lymphoproliferative phenotype (ALPS-like syndromes) corresponding to phenocopies of primary immunodeficiency (PID) (NRAS, KRAS), susceptibility to EBV (MAGT1, PRKCD, XIAP, SH2D1A, RASGRP1, TNFRSF9), antibody deficiency (PIK3CD gain of function (GOF), PIK3R1 loss of function (LOF), CARD11 GOF), regulatory T-cells defects (CTLA4, LRBA, STAT3 GOF, IL2RA, IL2RB, DEF6), combined immunodeficiencies (ITK, STK4), defects in intrinsic and innate immunity and predisposition to infection (STAT1 GOF, IL12RB1) and autoimmunity/autoinflammation (ADA2, TNFAIP3,TPP2, TET2). CTLA4 and LRBA patients correspond around to 50% of total ALPS-like cases. However, only 100% of CTLA4, PRKCD, TET2 and NRAS/KRAS reported patients had an ALPS-like presentation, while the autoimmunity and lymphoproliferation combination resulted rare in other genetic defects. Recurrent infections, skin lesions, enteropathy and malignancy are the most common clinical manifestations. Some approaches available for the immunological study and identification of ALPS-like patients through flow cytometry and ALPS biomarkers are provided in this work. Protein expression assays for NKG2D, XIAP, SAP, CTLA4 and LRBA deficiencies and functional studies of AKT, STAT1 and STAT3 phosphorylation, are showed as useful tests. Patients suspected to suffer from one of these disorders require rapid and correct diagnosis allowing initiation of tailored specific therapeutic strategies and monitoring thereby improving the prognosis and their quality of life.

The Use of Biologic Modifiers as a Bridge to Hematopoietic Cell Transplantation in Primary Immune Regulatory Disorders.

Recently, primary immune regulatory disorders have been described as a subset of inborn errors of immunity that are dominated by immune mediated pathology. As the pathophysiology of disease is elucidated, use of biologic modifiers have been increasingly used successfully to treat disease mediated clinical manifestations. Hematopoietic cell transplant (HCT) has also provided definitive therapy in several PIRDs. Although biologic modifiers have been largely successful at treating disease related manifestations, data are lacking regarding long term efficacy, safety, and their use as a bridge to HCT. This review highlights biologic modifiers in the treatment of several PIRDs and there use as a therapeutic bridge to HCT.