Paracoccidioidomycosis Associated With a Heterozygous STAT4 Mutation and Impaired IFN-γ Immunity

JAK/STAT defects and immune dysregulation, and guiding therapeutic choices

Inborn errors of immunity (IEIs) encompass a diverse spectrum of genetic disorders that disrupt the intricate mechanisms of the immune system, leading to a variety of clinical manifestations. Traditionally associated with an increased susceptibility to recurrent infections, IEIs have unveiled a broader clinical landscape, encompassing immune dysregulation disorders characterized by autoimmunity, severe allergy, lymphoproliferation, and even malignancy. This review delves into the intricate interplay between IEIs and the JAK-STAT signaling pathway, a critical regulator of immune homeostasis. Mutations within this pathway can lead to a wide array of clinical presentations, even within the same gene. This heterogeneity poses a significant challenge, necessitating individually tailored therapeutic approaches to effectively manage the diverse manifestations of these disorders. Additionally, JAK-STAT pathway defects can lead to simultaneous susceptibility to both infection and immune dysregulation. JAK inhibitors, with their ability to suppress JAK-STAT signaling, have emerged as powerful tools in controlling immune dysregulation. However, questions remain regarding the optimal selection and dosing regimens for each specific condition. Hematopoietic stem cell transplantation (HSCT) holds promise as a curative therapy for many JAK-STAT pathway disorders, but this procedure carries significant risks. The use of JAK inhibitors as a bridge to HSCT has been proposed as a potential strategy to mitigate these risks.

Selectivity, efficacy and safety of JAKinibs: new evidence for a still evolving story

Fundamental insight gained over the last decades led to the discovery of cytokines as pivotal drivers of inflammatory diseases such as rheumatoid arthritis, psoriasis/psoriasis arthritis, inflammatory bowel diseases, atopic dermatitis and spondylarthritis. A deeper understanding of the pro-inflammatory and anti-inflammatory effects of various cytokines has prompted new cytokine-targeting therapies, which revolutionised the treatment options in the last years for patients with inflammatory disorders. Disease-associated immune responses typically involve a complex interplay of multiple cytokines. Therefore, blockade of one single cytokine does not necessarily lead to a persistent remission in all patients with inflammatory disorders and fostered new therapeutic strategies targeting intracellular pathways shared by multiple cytokines. By inhibiting JAK-STAT signalling pathways common to families of cytokines, JAK-inhibitors (JAKinibs) have created a new paradigm for the treatment of inflammatory diseases. Multiple agents have been approved for various disorders and more are being investigated for several new indications. Second-generation selective JAKinibs have been devised with the aim to achieve an increased selectivity and a possible reduced risk of side effects. In the current review, we will summarise the current body of evidence of pan versus selective JAKinibs and the most recent insights on new side effects and indications, including COVID-19.

Interplay between epigenetic and genetic alterations in inborn errors of immunity

Inborn errors of immunity (IEIs) comprise a variety of immune conditions leading to infections, autoimmunity, allergy, and cancer. Some IEIs have no identified mutation(s), while others with identical mutations can display heterogeneous presentations. These observations suggest the involvement of epigenetic mechanisms. Epigenetic alterations can arise from downstream activation of cellular pathways through both extracellular stimulation and genetic-associated changes, impacting epigenetic enzymes or their interactors. Therefore, we posit that epigenetic alterations and genetic defects do not exclude each other as a disease-causing etiology. In this opinion, encompassing both basic and clinical viewpoints, we focus on selected IEIs with mutations in transcription factors that interact with epigenetic enzymes. The intricate interplay between these factors offers insights into genetic and epigenetic mechanisms in IEIs.

Deficiencies and Dysregulation of STAT Pathways That Drive Inborn Errors of Immunity: Lessons from Patients and Mouse Models of Disease

The STAT family proteins provide critical signals for immune cell development, differentiation, and proinflammatory and anti-inflammatory responses. Inborn errors of immunity (IEIs) are caused by single gene defects leading to immune deficiency and/or dysregulation, and they have provided opportunities to identify genes important for regulating the human immune response. Studies of patients with IEIs due to altered STAT signaling, and mouse models of these diseases, have helped to shape current understanding of the mechanisms whereby STAT signaling and protein interactions regulate immunity. Although many STAT signaling pathways are shared, clinical and immune phenotypes in patients with monogenic defects of STAT signaling highlight both redundant and nonredundant pathways. In this review, we provide an overview of the shared and unique signaling pathways used by STATs, phenotypes of IEIs with altered STAT signaling, and recent discoveries that have provided insight into the human immune response and treatment of disease.

Early Use of Low-Dose Ruxolitinib: A Promising Strategy for the Treatment of Acute and Chronic GVHD

Janus kinases (JAK) are a family of tyrosine kinases (JAK1, JAK2, JAK3, and TYK2) that transduce cytokine-mediated signals through the JAK–STAT metabolic pathway. These kinases act by regulating the transcription of specific genes capable of inducing biological responses in several immune cell subsets. Inhibition of Janus kinases interferes with the JAK–STAT signaling pathway. Besides being used in the treatment of cancer and inflammatory diseases, in recent years, they have also been used to treat inflammatory conditions, such as graft-versus-host disease (GVHD) and cytokine release syndrome as complications of allogeneic hematopoietic stem cell transplantation and cell therapy. Recently, the FDA approved the use of ruxolitinib, a JAK1/2 inhibitor, in the treatment of acute steroid-refractory GVHD (SR-aGVHD), highlighting the role of JAK inhibition in this immune deregulation. Ruxolitinib was initially used to treat myelofibrosis and true polycythemia in a high-dose treatment and caused hematological toxicity. Since a lower dosage often could not be effective, the use of ruxolitinib was suspended. Subsequently, ruxolitinib was evaluated in adult patients with SR-aGVHD and was found to achieve a rapid and effective response. In addition, its early low-dose use in pediatric patients affected by GVHD has proved effective, safe, and reasonably preventive. The review aims to describe the potential properties of ruxolitinib to identify new therapeutic strategies.

Transcription factors and regulators pathway-focused genes expression analysis in patients with different forms of thyroid pathology

BACKGROUND

Autoimmune thyroiditis (AIT) is a T cell-mediated organ-specific disorder and transcription factors have a critical role in the regulation of immune responses, especially in the fate of T-helper cells.

OBJECTIVE

This study aims to investigate changes in the gene expression profile of transcription factors and regulators in patients with different forms of thyroid pathology Methods. We used the pathway-specific real-time PCR array (Neurotrophins and Receptors RT2 Profiler PCR Array, QIAGEN, Germany) to identify and verify transcription factors and regulators pathway-focused genes expression in peripheral white blood cells of patients with postoperative hypothyroidism, hypothyroidism as a result of AIT and AIT with elevated serum an anti-thyroglobulin (anti-Tg) and anti-thyroid peroxidase (anti-TPO) antibodies.

RESULTS

It was shown that in patients with postoperative hypothyroidism FOS, NR1I2, STAT4, and TP53 significantly increased their expression whereas the expression of STAT1, STAT2, and STAT3 decreased. In patients with hypothyroidism as a result of AIT, we have found increased expression of NR1I2, STAT2, and STAT3. In contrast, the expression of STAT1 and TP53 decreased. FOS and STAT4 mRNAs did not change their expression. In patients with AIT and elevated serum anti-Tg and anti-TPO antibodies, the expression of FOS and NR1I2 reduced whereas the mRNA level of STAT3 increased. STAT1, STAT2, and STAT4 mRNAs did not change their expression. MYC did not change its expression in all groups of patients.

CONCLUSIONS

The results of this study demonstrate that autoimmune thyroiditis and hypothyroidism affect the mRNA-level expression of transcription factors and regulators genes in a gene-specific manner and that these changes to genes expression can be among the triggers of autoimmune inflammation progression in the thyroid gland.

The network interplay of interferon and Toll-like receptor signaling pathways in the anti-Candida immune response

Fungal infections represent a major global health problem affecting over a billion people that kills more than 1.5 million annually. In this study, we employed an integrative approach to reveal the landscape of the human immune responses to Candida spp. through meta-analysis of microarray, bulk, and single-cell RNA sequencing (scRNA-seq) data for the blood transcriptome. We identified across these different studies a consistent interconnected network interplay of signaling molecules involved in both Toll-like receptor (TLR) and interferon (IFN) signaling cascades that is activated in response to different Candida species (C. albicans, C. auris, C. glabrata, C. parapsilosis, and C. tropicalis). Among these molecules are several types I IFN, indicating an overlap with antiviral immune responses. scRNA-seq data confirmed that genes commonly identified by the three transcriptomic methods show cell type-specific expression patterns in various innate and adaptive immune cells. These findings shed new light on the anti-Candida immune response, providing putative molecular pathways for therapeutic intervention.

JAK-STAT signaling in human disease: From genetic syndromes to clinical inhibition

Since its discovery, the Janus kinase-signal transduction and activation of transcription (JAK-STAT) pathway has become recognized as a central mediator of widespread and varied human physiological processes. The field of JAK-STAT biology, particularly its clinical relevance, continues to be shaped by 2 important advances. First, the increased use of genomic sequencing has led to the discovery of novel clinical syndromes caused by mutations in JAK and STAT genes. This has provided insights regarding the consequences of aberrant JAK-STAT signaling for immunity, lymphoproliferation, and malignancy. In addition, since the approval of ruxolitinib and tofacitinib, the therapeutic use of JAK inhibitors (jakinibs) has expanded to include a large spectrum of diseases. Efficacy and safety data from over a decade of clinical studies have provided additional mechanistic insights while improving the care of patients with inflammatory and neoplastic conditions. This review discusses major advances in the field, focusing on updates in genetic diseases and in studies of clinical jakinibs in human disease.

Novel IL-β12R1 deficiency-mediates recurrent cutaneous leishmaniasis

BACKGROUND

The IL-12/IFN-γ axis plays a vital role in the control of intramacrophagic pathogens including Leishmania infections.

OBJECTIVE

The aim of this study was to investigate genetic defects in the IL-12/IFN-γ axis in cutaneous leishmaniasis patients, using immunological and genetic evaluation.

METHODS

Enzyme-linked immunosorbent assay was used to quantify IFN-γ , while flow cytometry was performed to analyze surface IL-12Rβ1/IL-12Rβ2 expression and phosphorylation of signal transducers as well as the activator of transcription 4 (pSTAT4). Sequencing was carried out for genetic analysis.

RESULTS

The peripheral blood mononuclear cells from the two patients (P1 and P2) demonstrated impaired production of IFN-γ. Furthermore, abolishment of the surface expression of Il-12Rβ1 was observed in lymphocytes, with consequent impairment of STAT4 phosphorylation in the lymphocytes of P1 and P2. IL-12Rββ1 deficiency was identified, which was caused by a novel homozygous missense mutation (c.485>T/p.P162L) and a novel homozygous nonsense mutation (c.805G>T/P.E269*) in the IL-12Rβ2 gene of P1 and P2, respectively. In silico analyses predicted these novel mutations as being pathogenic, causing truncated proteins, with consequent inactivation.

CONCLUSION

Our data have expanded the phenotype and mutation spectra associated with IL-12Rβ1 deficiency, and suggest that patients with CL should be screened for mutations in genes of the IL-12/IFN-γ axis.

Untwining Anti-Tumor and Immunosuppressive Effects of JAK Inhibitors-A Strategy for Hematological Malignancies?

Simple Summary

The Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway is aberrantly activated in many malignancies. Inhibition of this pathway via JAK inhibitors (JAKinibs) is therefore an attractive therapeutic strategy underlined by Ruxolitinib (JAK1/2 inhibitor) being approved for the treatment of myeloproliferative neoplasms. As a consequence of the crucial role of the JAK-STAT pathway in the regulation of immune responses, inhibition of JAKs suppresses the immune system. This review article provides a thorough overview of the current knowledge on JAKinibs’ effects on immune cells in the context of hematological malignancies. We also discuss the potential use of JAKinibs for the treatment of diseases in which lymphocytes are the source of the malignancy.

Abstract

The Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway propagates signals from a variety of cytokines, contributing to cellular responses in health and disease. Gain of function mutations in JAKs or STATs are associated with malignancies, with JAK2^V617F being the main driver mutation in myeloproliferative neoplasms (MPN). Therefore, inhibition of this pathway is an attractive therapeutic strategy for different types of cancer. Numerous JAK inhibitors (JAKinibs) have entered clinical trials, including the JAK1/2 inhibitor Ruxolitinib approved for the treatment of MPN. Importantly, loss of function mutations in JAK-STAT members are a cause of immune suppression or deficiencies. MPN patients undergoing Ruxolitinib treatment are more susceptible to infections and secondary malignancies. This highlights the suppressive effects of JAKinibs on immune responses, which renders them successful in the treatment of autoimmune diseases but potentially detrimental for cancer patients. Here, we review the current knowledge on the effects of JAKinibs on immune cells in the context of hematological malignancies. Furthermore, we discuss the potential use of JAKinibs for the treatment of diseases in which lymphocytes are the source of malignancies. In summary, this review underlines the necessity of a robust immune profiling to provide the best benefit for JAKinib-treated patients.

β2 Integrin-Mediated Susceptibility to Paracoccidioides brasiliensis Experimental Infection in Mice

The earliest interaction between macrophages and Paracoccidioides brasiliensis is particularly important in paracoccidioidomycosis (PCM) progression, and surface proteins play a central role in this process. The present study investigated the contribution of β2 integrin in P. brasiliensis-macrophage interaction and PCM progression. We infected β2-low expression (CD18^low) and wild type (WT) mice with P. brasiliensis 18. Disease progression was evaluated for fungal burden, lung granulomatous lesions, nitrate levels, and serum antibody production. Besides, the in vitro capacity of macrophages to internalize and kill fungal yeasts was investigated. Our results revealed that CD18^low mice infected with Pb18 survived during the time analyzed; their lungs showed fewer granulomas, a lower fungal load, lower levels of nitrate, and production of high levels of IgG1 in comparison to WT animals. Our results revealed that in vitro macrophages from CD18^low mice slowly internalized yeast cells, showing a lower fungal burden compared to WT cells. The migration capacity of macrophages was compromised and showed a higher intensity in the lysosome signal when compared with WT mice. Our data suggest that β2 integrins play an important role in fungal survival inside macrophages, and once phagocytosed, the macrophage may serve as a protective environment for P. brasiliensis.

Genetic causes of growth hormone insensitivity beyond GHR

Growth hormone insensitivity (GHI) syndrome, first described in 1966, is classically associated with monogenic defects in the GH receptor (GHR) gene which result in severe post-natal growth failure as consequences of insulin-like growth factor I (IGF-I) deficiency. Over the years, recognition of other monogenic defects downstream of GHR has greatly expanded understanding of primary causes of GHI and growth retardation, with either IGF-I deficiency or IGF-I insensitivity as clinical outcomes. Mutations in IGF1 and signaling component STAT5B disrupt IGF-I production, while defects in IGFALS and PAPPA2, disrupt transport and release of circulating IGF-I, respectively, affecting bioavailability of the growth-promoting IGF-I. Defects in IGF1R, cognate cell-surface receptor for IGF-I, disrupt not only IGF-I actions, but actions of the related IGF-II peptides. The importance of IGF-II for normal developmental growth is emphasized with recent identification of defects in the maternally imprinted IGF2 gene. Current application of next-generation genomic sequencing has expedited the pace of identifying new molecular defects in known genes or in new genes, thereby expanding the spectrum of GH and IGF insensitivity. This review discusses insights gained and future directions from patient-based molecular and functional studies.

Human growth disorders associated with impaired GH action: Defects in STAT5B and JAK2

Growth hormone (GH) promotes postnatal human growth primarily by regulating insulin-like growth factor (IGF)-I production through activation of the GH receptor (GHR)-JAK2-signal transducer and activator of transcription (STAT)-5B signaling pathway. Inactivating STAT5B mutations, both autosomal recessive (AR) and dominant-negative (DN), are causal of a spectrum of GH insensitivity (GHI) syndrome, IGF-I deficiency and postnatal growth failure. Only AR STAT5B defects, however, confer additional characteristics of immune dysfunction which can manifest as chronic, potentially fatal, pulmonary disease. Somatic activating STAT5B and JAK2 mutations are associated with a plethora of immune abnormalities but appear not to impact human linear growth. In this review, molecular defects associated with STAT5B deficiency is highlighted and insights towards understanding human growth and immunity is emphasized.

Genetic susceptibility to fungal infection in children

PURPOSE OF REVIEW

Fungal infections have steadily increased in incidence, emerging as a significant cause of morbidity and mortality in patients with iatrogenic immunosuppression. Simultaneously, we have witnessed a growing population of newly described inherited immune disorders that have enhanced our understanding of the human immune response against fungi. In the present review, we provide an overview and diagnostic roadmap to inherited disorders which confer susceptibility to superficial and invasive fungal infections.

RECENT FINDINGS

Inborn errors of fungal immunity encompass a heterogeneous group of disorders, some of which confer fungal infection-specific susceptibility, whereas others also feature broader infection vulnerability and/or noninfectious manifestations. Infections by Candida, Aspergillus, endemic dimorphic fungi, Pneumocystis, and dermatophytes along with their organ-specific presentations provide clinicians with important clues in the assessment of patients with suspected immune defects.

SUMMARY

The absence of iatrogenic risk factors should raise suspicion for inborn errors of immunity in children and young adults with recurrent or severe fungal diseases. Expeditious diagnosis and prompt initiation of antifungal therapy and management of complications are paramount to achieve remission of fungal disease in the setting of primary immunodeficiency disorders.

Unraveling the susceptibility of paracoccidioidomycosis: Insights towards the pathogen-immune interplay and immunogenetics

Paracoccidioidomycosis (PCM) is a life-threatening systemic mycosis caused by Paracoccidioides spp. This disease comprises three clinical forms: symptomatic acute and chronic forms (PCM disease) and PCM infection, a latent form without clinical symptoms. PCM disease differs markedly according to severity, clinical manifestations, and host immune response. Fungal virulence factors and adhesion molecules are determinants for entry, latency, immune escape and invasion, and dissemination in the host. Neutrophils and macrophages play a paramount role in first-line defense against the fungus through the recognition of antigens by pattern recognition receptors (PRRs), activating their microbicidal machinery. Furthermore, the clinical outcome of the PCM is strongly associated with the variability of cytokines and immunoglobulins produced by T and B cells. While the mechanisms that mediate susceptibility or resistance to infection are dictated by the immune system, some genetic factors may alter gene expression and its final products and, hence, modulate how the organism responds to infection and injury. This review outlines the main findings relative to this topic, addressing the complexity of the immune response triggered by Paracoccidioides spp. infection from preclinical investigations to studies in humans. Here, we focus on mechanisms of fungal pathogenesis, the patterns of innate and adaptive immunity, and the genetic and molecular basis related to immune response and susceptibility to the development of the PCM and its clinical forms. Immunogenetic features such as HLA system, cytokines/cytokines receptors genes and other immune-related genes, and miRNAs are likewise discussed. Finally, we point out the occurrence of PCM in patients with primary immunodeficiencies and call attention to the research gaps and challenges faced by the PCM field.

Primary immunodeficiencies and invasive fungal infection: when to suspect and how to diagnose and manage

PURPOSE OF REVIEW

Invasive fungal infections (IFIs) most often occur secondary to acquired immunodeficiency states such as transplantation, AIDS or immune-modulatory treatment for neoplastic and autoimmune disorders. Apart from these acquired conditions, several primary immunodeficiency disorders (PIDs) can present with IFIs in the absence of iatrogenic immunosuppression. This review highlights recent advances in our understanding of PIDs that cause IFIs, which may help clinicians in the diagnosis and management of such infections.

RECENT FINDINGS

A growing number of PIDs that cause varying combinations of invasive infections by commensal Candida, inhaled molds (primarily Aspergillus), Cryptococcus, Pneumocystis, endemic dimorphic fungi, dermatophytes, and/or agents of phaeohyphomycosis has uncovered the organ- and fungus-specific requirements for effective antifungal host defense in humans. Employing certain diagnostic algorithms tailored to the infecting fungus can facilitate the genetic diagnosis of the underlying PID, which has implications for the optimal management of affected patients.

SUMMARY

Heightened clinical suspicion is required for the diagnosis of underlying genetic defects in patients who develop IFIs in the absence of acquired immunodeficiency. Early initiation of antifungal therapy followed by long-term secondary prophylaxis is typically needed to achieve remission, but hematopoietic stem-cell transplantation may sometimes be necessary to promote immune restoration and infection control.

Comparison of clinico-epidemiological and radiological features in paracoccidioidomycosis patients regarding serological classification using antigens from Paracoccidioides brasiliensis complex and Paracoccidioides lutzii

Genotyping of the genus Paracoccidioides showed its diversity and geographical distribution. Four species constituting the Paracoccidioides brasiliensis complex and Paracoccidioides lutzii are etiological agents of paracoccidioidomycosis (PCM). However, there are no studies comparing the clinical and epidemiological aspects between PCM caused by the P. brasiliensis complex and by P. lutzii. Demographic and clinical data from 81 patients with PCM-confirmed by mycological and/or histopathological examination-from Mato Grosso do Sul state (Brazil) were studied. All patients underwent serology by immunodiffusion with antigens obtained from the P. brasiliensis complex (ExoPb and gp43) and Cell Free Antigens obtained from P.lutzii (CFAPl).The cases were classified regarding their serological profile into three groups: G1: PCM patients seropositive to ExoPb and/or gp43 and seronegative to CFAPl (n = 51), assumed to have PCM caused by P. brasiliensis complex; G2: PCM patients seronegative to gp43 and seropositive to CFAPl (n = 16), with PCM caused by P. lutzii; and G3: PCM patients seropositive to ExoPb or gp43 and seropositive to CFAPl (n = 14), with undetermined serological profile, was excluded from the analyses. The Fisher's exact test or the Mann-Whitney U test, and cluster analysis according to Ward's method and Euclidean distance were used to analyze the results. Patients with serological profile suggestive of P. lutzii lived predominantly in municipalities in the Central and Southern regions of the state, while those with serological profile indicative of the P. brasiliensis complex were distributed throughout the state. No differences were found between the two groups regarding gender, age, schooling, rural work, clinical form, severity, organs involved, intensity of pulmonary involvement, degree of anemia, erythrocyte sedimentation rate values, and therapeutic response. PCM patients with serological profile suggestive of P. lutzii and PCM patients with serological profile indicative of P. brasiliensis complex showed the same clinical and radiological presentations.

Human diseases caused by impaired signal transducer and activator of transcription and Janus kinase signaling

PURPOSE OF REVIEW

The Janus kinase (JAK) and signal transducer of activation (STAT) pathway plays a key role in the immune system. It is employed by diverse cytokines, interferons, growth factors and related molecules. Mutations in JAK/STAT pathway have been implicated in human disease. Here we review JAK/STAT biology and diseases associated with mutations in this pathway.

RECENT FINDINGS

Over the past 10 years, many mutations in JAK/STAT pathway has been discovered. These disorders have provided insights to human immunology.

SUMMARY

In this review, we summarize the biology of each STAT and JAK as well as discuss the human disease that results from somatic or germline mutations to include typical presentation, immunological parameters and treatment.

JAK/STAT Cytokine Signaling at the Crossroad of NK Cell Development and Maturation

Natural Killer (NK) cells are cytotoxic lymphocytes of the innate immune system and play a critical role in anti-viral and anti-tumor responses. NK cells develop in the bone marrow from hematopoietic stem cells (HSCs) that differentiate through common lymphoid progenitors (CLPs) to NK lineage-restricted progenitors (NKPs). The orchestrated action of multiple cytokines is crucial for NK cell development and maturation. Many of these cytokines such as IL-2, IL-7, IL-12, IL-15, IL-21, IL-27, and interferons (IFNs) signal via the Janus Kinase / Signal Transducer and Activator of Transcription (JAK/STAT) pathway. We here review the current knowledge about these cytokines and the downstream signaling involved in the development and maturation of conventional NK cells and their close relatives, innate lymphoid cells type 1 (ILC1). We further discuss the role of suppressor of cytokine signaling (SOCS) proteins in NK cells and highlight their potential for therapeutic application.

Dysregulatory syndromes: the role of signal transducers and activators of transcription

PURPOSE OF REVIEW

A comparative description of dysregulatory syndromes with mutations in signal transducer and activator of transcription (STAT) genes.

RECENT FINDINGS

STAT 1, 3 and 5b loss of function (LOF) and gain of function (GOF) mutations are a heterogeneous group of genetic disorders that range from immunodeficiency (ID) to autoimmune disease (AID), depending on the underlying signalling pathway defect. Between them, there are clear overlapping and differences in clinical presentation and laboratory findings.

SUMMARY

Dysregulatory syndromes due to LOF and GOF mutations in STAT1, 3 and 5b are a particular group of primary immunodeficiencies (PIDs) in which AID may be the predominant finding in addition to infections susceptibility. STAT1 GOF mutations were described as the major cause of chronic mucocutaneous candidiasis, while activating STAT3 mutations result in early-onset multiorgan autoimmunity and ID. Human STAT5b deficiency is a rare disease that also involves ID and severe growth failure. In recent years, the identification of the genes involved in these disorders allowed to differentiate these overlapping syndromes in order to choose the most effective therapeutic options.