Risks of Ruxolitinib in STAT1 Gain-of-Function-Associated Severe Fungal Disease

Heterozygous STAT1 gain-of-function (GOF) mutations are associated with chronic mucocutaneous candidiasis and a broad spectrum of infectious, inflammatory, and vascular manifestations. We describe therapeutic failures with the Janus Kinase (JAK) inhibitor ruxolitinib in 2 STAT1 GOF patients with severe invasive or cutaneous fungal infections.

Autosomal Dominant Hyper-IgE Syndrome in the USIDNET Registry

BACKGROUND

Autosomal dominant hyper-IgE syndrome (AD-HIES) is a rare condition.

OBJECTIVE

Data from the USIDNET Registry provide a resource to examine the characteristics of patients with rare immune deficiency diseases.

METHODS

A query was submitted to the USIDNET requesting deidentified data for patients with physician-diagnosed AD-HIES through July 2016.

RESULTS

Data on 85 patients diagnosed with AD-HIES (50 males; 35 females) born between 1950 and 2013, collected by 14 physicians from 25 states and Quebec, were entered into the USIDNET Registry by July 2016. Cumulative follow-up was 2157 years. Of these patients, 45.9% had a family history of HIES. The complications reported included skin abscesses (74.4%), eczema (57.7%), retained primary teeth (41.4%), fractures (39%), scoliosis (34.1%), and cancer (7%). Reported allergic diseases included food (37.8%), environmental (18%), and drugs (42.7%). The mean serum IgE level was 8383.7 kU/mL and was inversely correlated to the patient's age. A total of 49.4% had eosinophilia; 56% were known to be on trimethoprim-sulfamethoxazole, 26.6% on antifungal coverage, and 30.6% on immunoglobulin replacement therapy. Pneumonias were more commonly attributed to Staphylococcus aureus (55.3%) or Aspergillus fumigatus (22.4%); 19.5% had a history of lung abscess; these were most often associated with Pseudomonas aeruginosa (P Fisher's exact test = .029) or A. fumigatus (P Fisher's exact test = .016). Lung abscesses were significantly associated with drug reactions (P χ² = .01; odds ratio: 4.03 [1.2-12.97]), depression (P Fisher's exact test = .036), and lower Karnofsky index scores (P Mann-Whitney = .007).

DISCUSSION

Data from the USIDNET Registry summarize the currently reported clinical characteristics of a large cohort of subjects with AD-HIES.

Gastrointestinal Manifestations of STAT3-Deficient Hyper-IgE Syndrome

OBJECTIVE

STAT 3 deficiency (autosomal dominant hyper immunoglobulin E syndrome (AD-HIES)) is a primary immunodeficiency disorder with multi-organ involvement caused by dominant negative signal transducer and activator of transcription gene 3 (STAT3) mutations. We sought to describe the gastrointestinal (GI) manifestations of this disease.

METHODS

Seventy subjects aged five to 60 years with a molecular diagnosis of AD-HIES were evaluated at the National Institutes of Health (NIH). Data collection involved a GI symptom questionnaire and retrospective chart review.

RESULTS

In our cohort of 70 subjects, we found that 60% had GI symptoms (42/70). The most common manifestations were gastroesophageal reflux disease (GERD) observed in 41%, dysphagia in 31%, and abdominal pain in 24%. The most serious complications were food impaction in 13% and colonic perforation in 6%. Diffuse esophageal wall thickening in 74%, solid stool in the right colon in 50% (12/24), and hiatal hernia in 26% were the most prevalent radiologic findings. Esophagogastroduodenoscopy (EGD) demonstrated esophageal tortuosity in 35% (8/23), esophageal ulceration in 17% (4/23), esophageal strictures requiring dilation in 9% (2/23), and gastric ulceration in 17% (4/23). Esophageal eosinophilic infiltration was an unexpected histologic finding seen in 65% (11/17).

CONCLUSION

The majority of AD-HIES subjects develop GI manifestations as part of their disease. Most notable are the symptoms and radiologic findings of GI dysmotility, as well as significant eosinophilic infiltration, concerning for a secondary eosinophilic esophagitis. These findings suggest that the STAT3 pathway may be implicated in a new mechanism for the pathogenesis of several GI disorders.

Emerging Infections and Pertinent Infections Related to Travel for Patients with Primary Immunodeficiencies

In today's global economy and affordable vacation travel, it is increasingly important that visitors to another country and their physician be familiar with emerging infections, infections unique to a specific geographic region, and risks related to the process of travel. This is never more important than for patients with primary immunodeficiency disorders (PIDD). A recent review addressing common causes of fever in travelers provides important information for the general population Thwaites and Day (N Engl J Med 376:548-560, 2017). This review covers critical infectious and management concerns specifically related to travel for patients with PIDD. This review will discuss the context of the changing landscape of infections, highlight specific infections of concern, and profile distinct infection phenotypes in patients who are immune compromised. The organization of this review will address the environment driving emerging infections and several concerns unique to patients with PIDD. The first section addresses general considerations, the second section profiles specific infections organized according to mechanism of transmission, and the third section focuses on unique phenotypes and unique susceptibilities in patients with PIDDs. This review does not address most parasitic diseases. Reference tables provide easily accessible information on a broader range of infections than is described in the text.

A biallelic mutation in IL6ST encoding the GP130 co-receptor causes immunodeficiency and craniosynostosis

Multiple cytokines, including interleukin 6 (IL-6), IL-11, IL-27, oncostatin M (OSM), and leukemia inhibitory factor (LIF), signal via the common GP130 cytokine receptor subunit. In this study, we describe a patient with a homozygous mutation of IL6ST (encoding GP130 p.N404Y) who presented with recurrent infections, eczema, bronchiectasis, high IgE, eosinophilia, defective B cell memory, and an impaired acute-phase response, as well as skeletal abnormalities including craniosynostosis. The p.N404Y missense substitution is associated with loss of IL-6, IL-11, IL-27, and OSM signaling but a largely intact LIF response. This study identifies a novel immunodeficiency with phenotypic similarities to STAT3 hyper-IgE syndrome caused by loss of function of GP130.

PD-L1 up-regulation restrains Th17 cell differentiation in STAT3 loss- and STAT1 gain-of-function patients

Zhang et al. show that hyperphosphorylated STAT1 in patients with STAT1 gain-of-function and STAT3 loss-of-function is caused by impaired SOCS3 expression and leads to upregulation of PD-L1 and defects in Th17 cell differentiation that underlie susceptibility to chronic mucocutaneous candidiasis in these patients.

Patients with hypomorphic mutations in STAT3 and patients with hypermorphic mutations in STAT1 share several clinical and cellular phenotypes suggesting overlapping pathophysiologic mechanisms. We, therefore, examined cytokine signaling and CD4⁺ T cell differentiation in these cohorts to characterize common pathways. As expected, differentiation of Th17 cells was impaired in both cohorts. We found that STAT1 was hyperphosphorylated in response to cytokine stimulation in both cohorts and that STAT1-dependent PD-L1 up-regulation—known to inhibit Th17 differentiation in mouse models—was markedly enhanced as well. Overexpression of SOCS3 strongly inhibited phosphorylation of STAT1 and PD-L1 up-regulation, suggesting that diminished SOCS3 expression may lead to the observed effects. Defects in Th17 differentiation could be partially overcome in vitro via PD-L1 inhibition and in a mouse model of STAT3 loss-of-function by crossing them with PD-1 knockout mice. PD-L1 may be a potential therapeutic target in several genetic diseases of immune deficiency affecting cytokine signaling.

Molecular Typing of Staphylococcus aureus Isolated from Patients with Autosomal Dominant Hyper IgE Syndrome

Autosomal dominant hyper IgE syndrome (AD-HIES) is a primary immunodeficiency caused by a loss-of-function mutation in the Signal Transducer and Activator of Transcription 3 (STAT3). This immune disorder is clinically characterized by increased susceptibility to cutaneous and sinopulmonary infections, in particular with Candida and Staphylococcus aureus. It has recently been recognized that the skin microbiome of patients with AD-HIES is altered with an overrepresentation of certain Gram-negative bacteria and Gram-positive staphylococci. However, these alterations have not been characterized at the species- and strain-level. Since S. aureus infections are influenced by strain-specific expression of virulence factors, information on colonizing strain characteristics may provide insights into host-pathogen interactions and help guide management strategies for treatment and prophylaxis. The aim of this study was to determine whether the immunodeficiency of AD-HIES selects for unique strains of colonizing S. aureus. Using multi-locus sequence typing (MLST), protein A (spa) typing, and PCR-based detection of toxin genes, we performed a detailed analysis of the S. aureus isolates (n = 13) found on the skin of twenty-one patients with AD-HIES. We found a low diversity of sequence types, and an abundance of strains that expressed methicillin resistance, Panton-Valentine leukocidin (PVL), and staphylococcal enterotoxins K and Q (SEK, SEQ). Our results indicate that patients with AD-HIES may often carry antibiotic-resistant strains that harbor key virulence factors.

Haploidentical Related Donor Hematopoietic Stem Cell Transplantation for Dedicator-of-Cytokinesis 8 Deficiency Using Post-Transplantation Cyclophosphamide

Dedicator-of-cytokinesis 8 (DOCK8) deficiency, a primary immunodeficiency disease, can be reversed by allogeneic hematopoietic stem cell transplantation (HSCT); however, there are few reports describing the use of alternative donor sources for HSCT in DOCK8 deficiency. We describe HSCT for patients with DOCK8 deficiency who lack a matched related or unrelated donor using bone marrow from haploidentical related donors and post-transplantation cyclophosphamide (PT/Cy) for graft-versus-host disease (GVHD) prophylaxis. Seven patients with DOCK8 deficiency (median age, 20 years; range, 7 to 25 years) received a haploidentical related donor HSCT. The conditioning regimen included 2 days of low-dose cyclophosphamide, 5 days of fludarabine, 3 days of busulfan, and 200 cGy total body irradiation. GVHD prophylaxis consisted of PT/Cy 50 mg/kg/day on days +3 and +4 and tacrolimus and mycophenolate mofetil starting at day +5. The median times to neutrophil and platelet engraftment were 15 and 19 days, respectively. All patients attained >90% donor engraftment by day +30. Four subjects developed acute GVHD (1 with maximum grade 3). No patient developed chronic GVHD. With a median follow-up time of 20.6 months (range, 9.5 to 31.7 months), 6 of 7 patients are alive and disease free. Haploidentical related donor HSCT with PT/Cy represents an effective therapeutic approach for patients with DOCK8 deficiency who lack a matched related or unrelated donor.

Abstract 618: Hypoxia Inducible Factor 1a Stabilization in Autosomal Dominant Hyper IgE Syndrome Fibroblasts Rescues Impaired Ability to Support Angiogenesis

Background: Autosomal dominant Hyper-IgE syndrome (AD-HIES) is a rare primary immunodeficiency caused by dominant negative mutations in signal transducer and activator of transcription 3 (STAT3 ) , a mediator of widespread physiological processes. It is characterized by dermatitis, recurrent infections, elevated IgE, poor post-surgical healing, and connective tissue abnormalities. How STAT3 deficiency leads to this phenotype, however, is not known. Current treatment options are limited to antimicrobials for infection control. The aim of this study was to investigate which of STAT3’s many functions are dis-regulated in AD-HIES, and where potential targets for therapy may lie.

Methods: We used skin fibroblasts (SF) from 3 AD-HIES patients and 3 normal volunteers. To evaluate potentially affected pathways, we utilized RNA- Seq and subsequent Gene Set Enrichment (GSEA) and pathway analysis (Pathway Studio, GeneGo Metacore). Endothelial cell tube formation assay was used to assess ability of AD-HIES SFs to support angiogenesis.

Results: GSEA and pathway analysis showed deficiencies in signaling pathways linked to wound healing, extracellular matrix remodeling and angiogenesis including targets of Hypoxia Inducible Factor 1a (HIF1a) (P values for enrichments < 0.001) . Therefore, we hypothesized that AD-HIES SFs have impaired ability to support angiogenesis due to deficient Hif1a-dependent secretion of matrix proteases and growth factors. Indeed, AD-HIES SF secreted up to 5 times less matrix metalloprotease 1, 3, and 9, placental growth factor and fibroblast growth factors 1 and 2 (Luminex Multiplex, n=3-9, P<0.05). Culture medium from AD-HIES SFs failed to fully support tube formation by endothelial cells resulting in lower number of junctions, meshes, and total tubule length (n=6, P<0.005). Stabilization of Hif1a in AD-HIES SFs by prolyl hydroxylase inhibitor dimethyl fumarate restored its transcriptional activity leading to increased number of junctions, meshes, and tubule length (n=12, P<0.05)

Conclusion: AD-HIES SFs have deficiencies in pro-angiogenic signaling pathways that lead to decreased growth factor secretion and angiogenesis. Stabilization of HIF1a corrects this deficiency and is an enticing target for future therapy.

An alternative mechanism for durable protective immunity to Staphylococcus aureus skin infection

The immune mechanisms for durable immunity against S. aureus skin infections are unclear as reinfections are common despite specific antibodies and Th1/Th17 cells. Using a CA-MRSA skin reinfection model in mice involving a primary infection (1°) in the lower back (cleared by 14 days) followed by a secondary infection (2°) in the upper back on day 28, we found that 1° and 2° wt mice had similar responses. In contrast, 1° IL-1β−/− mice had increased lesions and bacterial burden with impaired neutrophil recruitment whereas 2° IL-1β−/− mice were protected and resembled wt mice. Transfer of serum containing CA-MRSA specific antibodies did not confer protection to 1° IL-1β−/− mice and depletion of CD4+ T cells did not alter the protection of 2° IL-1β−/− mice, indicating a lack of a role of antibodies or CD4+ T cells. However, 2° IL-1β−/− mice were no longer protected if the egress of lymphocytes from lymph nodes was blocked in 2° IL-1β−/− mice (FTY720 treatment) and the immune impairment in naïve IL-1β−/− mice could be rescued by adoptive transfer of total lymph nodes cells from d28 IL-1β−/− mice. Moreover, transfer of only 50,000 γδ T cells from lymph nodes of day 28 IL-1β−/− mice conferred protection to 1° IL-1β−/− mice. These γδ T cells produced IFNγ/TNF-α, but not IL-17/IL-22, and neutralizing IFNγ/TNF-α activity resulted in loss of protection in 2° IL-1β−/− mice. In humans, similar IFNγ/TNF-α-producing γδ T cells were found in individuals with IRAK4 deficiency whose susceptibility to S. aureus skin infections improves with age but not from individuals with chronic granulomatous disease whose susceptibility is lifelong. These findings define an alternative mechanism to therapeutically target for long-term protection against CA-MRSA skin infections.

Current Status of Dedicator of Cytokinesis-Associated Immunodeficiency: DOCK8 and DOCK2

DOCK8 deficiency is an autosomal recessive combined immunodeficiency disease associated with elevated IgE, atopy, recurrent sinopulmonary and cutaneous viral infections, and malignancy. The DOCK8 protein is critical for cytoskeletal organization, and deficiency impairs dendritic cell transmigration, T-cell survival, and NK cell cytotoxicity. Early hematopoietic stem cell transplantation is gaining prominence as a definitive treatment given the potential for severe complications and mortality in this disease. Recently, DOCK2 deficiency has been identified in several patients with early-onset invasive bacterial and viral infections.

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.

ERBIN deficiency links STAT3 and TGF-β pathway defects with atopy in humans

Lyons et al. show that STAT3 negatively regulates TGF-β signaling via ERBIN and that cell-intrinsic deregulation of TGF-β pathway activation promotes the IL-4/IL-4Rα/GATA3 axis to support atopic phenotypes in humans.

Nonimmunological connective tissue phenotypes in humans are common among some congenital and acquired allergic diseases. Several of these congenital disorders have been associated with either increased TGF-β activity or impaired STAT3 activation, suggesting that these pathways might intersect and that their disruption may contribute to atopy. In this study, we show that STAT3 negatively regulates TGF-β signaling via ERBB2-interacting protein (ERBIN), a SMAD anchor for receptor activation and SMAD2/3 binding protein. Individuals with dominant-negative STAT3 mutations (STAT3^mut) or a loss-of-function mutation in ERBB2IP (ERBB2IP^mut) have evidence of deregulated TGF-β signaling with increased regulatory T cells and total FOXP3 expression. These naturally occurring mutations, recapitulated in vitro, impair STAT3–ERBIN–SMAD2/3 complex formation and fail to constrain nuclear pSMAD2/3 in response to TGF-β. In turn, cell-intrinsic deregulation of TGF-β signaling is associated with increased functional IL-4Rα expression on naive lymphocytes and can induce expression and activation of the IL-4/IL-4Rα/GATA3 axis in vitro. These findings link increased TGF-β pathway activation in ERBB2IP^mut and STAT3^mut patient lymphocytes with increased T helper type 2 cytokine expression and elevated IgE.

DOCK 8 Deficiency, EBV+ Lymphomatoid Granulomatosis, and Intrafamilial Variation in Presentation

Dedicator of cytokinesis 8 (DOCK8) deficiency is an autosomal recessive, combined immunodeficiency within the spectrum of hyper-IgE syndromes. Epstein-Barr virus-positive lymphomatoid granulomatosis (LYG) (EBV + LYG) is a rare diagnosis and a previously unreported presentation of DOCK8 deficiency. A 10-year-old girl was initially evaluated for mild eczema and recurrent sinopulmonary infections. She had normal immunoglobulins with elevated IgE, poor polysaccharide response with low switched memory B cells, low CD4 count, and normal mitogen and antigen responses. Despite clinical improvement following immunoglobulin replacement, a prolonged cough prompted a CT scan, which showed nodules. Biopsy identified a Grade 2 EBV + LYG. Due to an inadequate response with chemotherapy, further workup for primary immunodeficiency was performed. With her symptoms of eczema and IgE elevation, along with her brother's history of recurrent sinopulmonary infections and warts, targeted sequencing of DOCK8 was performed revealing compound heterozygous mutations for the two siblings. Both patients were successfully transplanted with resolution of the LYG and warts, respectively. This is the first reported case of LYG in DOCK8 deficiency. The EBV-driven lymphoproliferative disease along with the infection history in the brother led to the diagnosis of DOCK8 deficiency and curative hematopoietic stem cell transplants.

Therapeutic drug monitoring of posaconazole oral suspension in paediatric patients younger than 13 years of age: a retrospective analysis and literature review

WHAT IS KNOWN AND OBJECTIVE

Posaconazole is an extended-spectrum triazole antifungal with activity against a variety of clinically significant yeasts and moulds. Posaconazole is not currently approved by the U.S. Food and Drug Administration for use in children younger than 13 years of age. Our primary objective was to describe the dosing and observed trough concentrations with posaconazole oral suspension in paediatric patients at the National Institutes of Health Clinical Center (Bethesda, MD).

METHODS

This retrospective single-centre study reviewed paediatric patients younger than 13 years of age initiated on posaconazole oral suspension. Patients were included if they were initiated on posaconazole for prophylaxis or treatment for fungal infections from September 2006 through March 2013 with at least one trough concentration collected after at least 7 days of therapy.

RESULTS AND DISCUSSION

A total of 20 male patients were included, of whom 15 (75%) had chronic granulomatous disease. The median age of patients was 6·5 years (range: 2·8-10·7). A total of 79 posaconazole trough concentrations were measured in patients receiving posaconazole as prophylaxis (n = 8) or treatment (n = 12). Posaconazole dose referenced to total body weight ranged from 10·0 to 49·2 mg/kg/day. Posaconazole trough concentrations ranged from undetectable (<50 ng/mL) up to 3620 ng/mL and were ≥500, ≥700 and ≥1250 ng/mL in 95%, 60% and 25% of patients, respectively.

WHAT IS NEW AND CONCLUSIONS

Patients younger than 13 years of age had highly variable trough concentrations, and recommendations for the appropriate dosing of posaconazole oral suspension remain challenging. Until studies are conducted to determine the appropriate dosing of posaconazole in this patient population, therapeutic drug monitoring should be considered to ensure adequate posaconazole exposure.

Mediastinal and Disseminated Mycobacterium kansasii Disease in GATA2 Deficiency

RATIONALE

Mycobacterium kansasii usually causes chronic pulmonary infections in immunocompetent patients. In contrast, disseminated M. kansasii disease is commonly associated with advanced human immunodeficiency virus infection, but is reported infrequently in other immunocompromised patients.

OBJECTIVES

To identify common clinical manifestations and potential risk factors for M. kansasii infection in patients with GATA2 deficiency.

METHODS

We reviewed M. kansasii disease associated with GATA2 deficiency at one institution and disease associated with primary and other immunodeficiencies reported in the literature.

MEASUREMENTS AND MAIN RESULTS

Nine patients with GATA2 deficiency developed M. kansasii infections. Six patients developed disseminated disease. All patients presented with significant mediastinal lymphadenopathy or abscesses. Seven patients had pulmonary risk factors, including six smokers. The majority of patients had low numbers of neutrophils, monocytes, B cells, CD4+ T cells, and natural killer cells. Other conditions associated with disseminated M. kansasii disease were thymic disorders and IFN-γ/IL-12 defects.

CONCLUSIONS

Disseminated M. kansasii disease involving mediastinal lymph nodes is surprisingly common in GATA2 deficiency, but also occurs in defects of IFN-γ synthesis and response. Disseminated M. kansasii should be considered a marker indicating a need to evaluate for immunodeficiency syndromes.

Extrapulmonary Aspergillus infection in patients with CARD9 deficiency

Invasive pulmonary aspergillosis is a life-threatening mycosis that only affects patients with immunosuppression, chemotherapy-induced neutropenia, transplantation, or congenital immunodeficiency. We studied the clinical, genetic, histological, and immunological features of 2 unrelated patients without known immunodeficiency who developed extrapulmonary invasive aspergillosis at the ages of 8 and 18. One patient died at age 12 with progressive intra-abdominal aspergillosis. The other patient had presented with intra-abdominal candidiasis at age 9, and developed central nervous system aspergillosis at age 18 and intra-abdominal aspergillosis at age 25. Neither patient developed Aspergillus infection of the lungs. One patient had homozygous M1I CARD9 (caspase recruitment domain family member 9) mutation, while the other had homozygous Q295X CARD9 mutation; both patients lacked CARD9 protein expression. The patients had normal monocyte and Th17 cell numbers in peripheral blood, but their mononuclear cells exhibited impaired production of proinflammatory cytokines upon fungus-specific stimulation. Neutrophil phagocytosis, killing, and oxidative burst against Aspergillus fumigatus were intact, but neither patient accumulated neutrophils in infected tissue despite normal neutrophil numbers in peripheral blood. The neutrophil tissue accumulation defect was not caused by defective neutrophil-intrinsic chemotaxis, indicating that production of neutrophil chemoattractants in extrapulmonary tissue is impaired in CARD9 deficiency. Taken together, our results show that CARD9 deficiency is the first known inherited or acquired condition that predisposes to extrapulmonary Aspergillus infection with sparing of the lungs, associated with impaired neutrophil recruitment to the site of infection.

Persistent nodal histoplasmosis in nuclear factor kappa B essential modulator deficiency: Report of a case and review of infection in primary immunodeficiencies

In the absence of acquired or secondary immunosuppression, mutations causing failure to properly activate the IL-12/IFN-γ pathway, NF-κB, or STAT3 should be excluded in patients presenting with severe histoplasmosis.

Hyper-IgE Syndromes and the Lung

Elevated serum IgE has many etiologies including parasitic infection, allergy and asthma, malignancy, and immune dysregulation. The hyper-IgE syndromes caused by mutations in STAT3, DOCK8, and PGM3 are monogenic primary immunodeficiencies associated with high IgE, eczema, and recurrent infections. These primary immunodeficiencies are associated with recurrent pneumonias leading to bronchiectasis; however, each has unique features and genetic diagnosis is essential in guiding therapy, discussing family planning, and defining prognosis. This article discusses the clinical features of these primary immunodeficiencies with a particular focus on the pulmonary manifestations and discussion of the genetics, pathogenesis, and approaches to therapy.

Eosinophilia Associated with Disorders of Immune Deficiency or Immune Dysregulation

Increased serum eosinophil levels have been associated with multiple disorders of immune deficiency or immune dysregulation. Although primary immunodeficiency diseases are rare, it is important to consider these in the differential diagnosis of patients with eosinophilia. In this review, the clinical features, laboratory findings, diagnosis, and genetic basis of disease of several disorders of immune deficiency or dysregulation are discussed. The article includes autosomal dominant hyper IgE syndrome, DOCK8 deficiency, phosphoglucomutase 3 deficiency, ADA-SCID, Omenn syndrome, Wiskott-Aldrich syndrome, Loeys-Dietz syndrome, autoimmune lymphoproliferative syndrome, immunodysregulation, polyendocrinopathy, enteropathy, X-linked syndrome, Comel-Netherton syndrome, and severe dermatitis, multiple allergies, and metabolic wasting syndrome.

Progressive Multifocal Leukoencephalopathy in Primary Immune Deficiencies: Stat1 Gain of Function and Review of the Literature

BACKGROUND

Progressive multifocal leukoencephalopathy (PML) is a rare, severe, otherwise fatal viral infection of the white matter of the brain caused by the polyomavirus JC virus, which typically occurs only in immunocompromised patients. One patient with dominant gain-of-function (GOF) mutation in signal transducer and activator of transcription 1 (STAT1) with chronic mucocutaneous candidiasis and PML was reported previously. We aim to identify the molecular defect in 3 patients with PML and to review the literature on PML in primary immune defects (PIDs).

METHODS

STAT1 was sequenced in 3 patients with PML. U3C cell lines were transfected with STAT1 and assays to search for STAT1 phosphorylation, transcriptional response, and target gene expression were performed.

RESULTS

We identified 3 new unrelated cases of PML in patients with GOF STAT1 mutations, including the novel STAT1 mutation, L400Q. These STAT1 mutations caused delayed STAT1 dephosphorylation and enhanced interferon-gamma-driven responses. In our review of the literature regarding PML in primary immune deficiencies we found 26 cases, only 54% of which were molecularly characterized, the remainder being syndromically diagnosed only.

CONCLUSIONS

The occurrence of PML in 4 cases of STAT1 GOF suggests that STAT1 plays a critical role in the control of JC virus in the central nervous system.

Flavivirus Antagonism of Type I Interferon Signaling Reveals Prolidase as a Regulator of IFNAR1 Surface Expression

Type I interferon (IFN-α/β or IFN-I) signals through two receptor subunits, IFNAR1 and IFNAR2, to orchestrate sterile and infectious immunity. Cellular pathways that regulate IFNAR1 are often targeted by viruses to suppress the antiviral effects of IFN-I. Here we report that encephalitic flaviviruses, including tick-borne encephalitis virus and West Nile virus, antagonize IFN-I signaling by inhibiting IFNAR1 surface expression. Loss of IFNAR1 was associated with binding of the viral IFN-I antagonist, NS5, to prolidase (PEPD), a cellular dipeptidase implicated in primary immune deficiencies in humans. Prolidase was required for IFNAR1 maturation and accumulation, activation of IFNβ-stimulated gene induction, and IFN-I-dependent viral control. Human fibroblasts derived from patients with genetic prolidase deficiency exhibited decreased IFNAR1 surface expression and reduced IFNβ-stimulated signaling. Thus, by understanding flavivirus IFN-I antagonism, prolidase is revealed as a central regulator of IFN-I responses.

Diminution of signal transducer and activator of transcription 3 signaling inhibits vascular permeability and anaphylaxis

BACKGROUND

During IgE-mediated immediate hypersensitivity reactions, vascular endothelial cells permeabilize in response to mast cell mediators. We have demonstrated previously that patients and mice with signal transducer and activator of transcription 3 (STAT3) mutations (autosomal dominant hyper-IgE syndrome [AD-HIES]) are partially protected from anaphylaxis.

OBJECTIVES

We sought to study the mechanism by which STAT3 contributes to anaphylaxis and determine whether small-molecule inhibition of STAT3 can prevent anaphylaxis.

METHODS

Using unaffected and STAT3-inhibited or genetic loss-of-function samples, we performed histamine skin prick tests, investigated the contribution of STAT3 to animal models of anaphylaxis, and measured endothelial cell permeability, gene and protein expression, and histamine receptor-mediated signaling.

RESULTS

Although mouse mast cell degranulation was minimally affected by STAT3 blockade, mast cell mediator-induced anaphylaxis was blunted in Stat3 mutant mice with AD-HIES and in wild-type mice subjected to small-molecule STAT3 inhibition. Histamine skin prick test responses were diminished in patients with AD-HIES. Human umbilical vein endothelial cells derived from patients with AD-HIES or treated with a STAT3 inhibitor did not signal properly through Src or cause appropriate dissolution of the adherens junctions made up of the proteins vascular endothelial-cadherin and β-catenin. Furthermore, we found that diminished STAT3 target microRNA17-92 expression in human umbilical vein endothelial cells from patients with AD-HIES is associated with increased phosphatase and tensin homolog (PTEN) expression, which inhibits Src, and increased E2F transcription factor 1 expression, which regulates β-catenin cellular dynamics.

CONCLUSIONS

These data demonstrate that STAT3-dependent transcriptional activity regulates critical components for the architecture and functional dynamics of endothelial junctions, thus permitting vascular permeability.

Primary immunodeficiency update: Part II. Syndromes associated with mucocutaneous candidiasis and noninfectious cutaneous manifestations

Several primary immunodeficiencies (PIDs) have recently been described that confer an elevated risk of fungal infections and noninfectious cutaneous manifestations. In addition, immunologic advances have provided new insights into our understanding of the pathophysiology of fungal infections in established PIDs. We reviewed PIDs that present with an eczematous dermatitis in part I. In part II of this continuing medical education article we discuss updates on PIDs associated with fungal infections, their biologic basis in PIDs, and noninfectious cutaneous manifestations.

Primary immunodeficiency update: Part I. Syndromes associated with eczematous dermatitis

In the past decade, the availability of powerful molecular techniques has accelerated the pace of discovery of several new primary immunodeficiencies (PIDs) and revealed the biologic basis of other established PIDs. These genetic advances, in turn, have facilitated more precise phenotyping of associated skin and systemic manifestations and provide a unique opportunity to better understand the complex human immunologic response. These continuing medical education articles will provide an update of recent advances in PIDs that may be encountered by dermatologists through their association with eczematous dermatitis, infectious, and non-infectious cutaneous manifestations. Part I will discuss new primary immunodeficiencies that have an eczematous dermatitis. Part II will focus on primary immunodeficiencies that greatly increase susceptibility to fungal infection and the noninfectious presentations of PIDs.

WU polyomavirus in respiratory epithelial cells from lung transplant patient with Job syndrome

We detected WU polyomavirus (WUPyV) in a bronchoalveolar lavage sample from lungs transplanted into a recipient with Job syndrome by using immunoassays specific for the WUPyV viral protein 1. Co-staining for an epithelial cell marker identified most WUPyV viral protein 1–positive cells as respiratory epithelial cells.

Drug-drug interaction between isavuconazole and tacrolimus: a case report indicating the need for tacrolimus drug-level monitoring

WHAT IS KNOWN AND OBJECTIVE

Despite the known significant drug-drug interaction between isavuconazole and tacrolimus, there are no recommendations on dose adjustment when these drugs are given concomitantly. We report on a patient with a mediastinal Aspergillus fumigatus infection resistant to posaconazole and describe how she was successfully managed with tacrolimus therapeutic drug-level monitoring.

CASE SUMMARY

Our patient presented with a mediastial Aspergillus fumigatus infection, 2 years after lung transplantation. A. fumigatus was resistant to posaconazole, and the patient had intolerance to voriconazole shown by elevated transaminases. The patient was given isavuconazole with drug-level monitoring. She was managed successfully with no adverse events. Tacrolimus concentration continued to increase after more than 2 weeks of therapy and required a further reduction to 72% of the usual dose to maintain the target concentrations over a 8-week period.

WHAT IS NEW AND CONCLUSION

When isavuconazole is given to patients on tacrolimus, the dose of the latter will need considerable reduction. We would suggest an initial 50% reduction and recommend close weekly monitoring of tacrolimus concentration. Further dose decreases of 25-50% may be required.

IL2RG reversion event in a common lymphoid progenitor leads to delayed diagnosis and milder phenotype

Severe combined immunodeficiency (SCID) is most frequently caused by mutations in the cytokine receptor common gamma chain, CD132, encoded by the X-linked gene, IL2RG. Most patients present in the first year of life with failure to thrive, severe, opportunistic infections and absence of CD3+ T cells. We present a patient with pediatric illness and a diagnosis of combined variable immune deficiency (CVID) who was diagnosed at age 23 with an inherited IL2RG mutation causing loss of signal transduction through CD132. His peripheral blood included CD3/CD4 and CD3/CD8 positive cells as well as low levels of CD19+ B cells containing a reversion to the wildtype IL2RG allele. The reversion, which was not present at birth, may account for his mild phenotype and late diagnosis.

T-Cell Depletion in the Colonic Mucosa of Patients With Idiopathic CD4+ Lymphopenia

Idiopathic CD4(+) lymphopenia (ICL) is a rare syndrome characterized by low peripheral CD4(+) T-cell counts that can lead to serious opportunistic infections. The pathogenesis of ICL remains unclear, and whether effector sites are also lymphopenic is unknown. In this study, rectosigmoid mucosal biopsy specimens from patients with ICL and healthy controls were evaluated. Significant T-cell lymphopenia was observed in the mucosal tissue of patients with ICL by flow cytometry and immunohistochemistry, compared with healthy controls. Functional capacity of T cells, assessed by production of interferon γ and interleukin 17, was preserved in the mucosa of patients with ICL. In contrast to T lymphocytes, the frequency of myeloid cells (neutrophils and macrophages) was elevated in the colonic mucosa of patients with ICL. Despite the observed mucosal abnormalities, plasma levels of intestinal fatty acid binding protein, a marker of enterocyte turnover and other inflammatory biomarkers, including interleukin 6, C-reactive protein, and tumor necrosis factor, were not elevated in patients with ICL, compared with healthy controls, whereas soluble CD14 levels were minimally elevated. These data suggest that patients with ICL, despite gut mucosal lymphopenia and local tissue inflammation, have preserved enterocyte turnover and T-helper type 17 cells with minimal systemic inflammation. These observations highlight differences from patients with human immunodeficiency virus infection, with or without AIDS, and may partially explain their distinct clinical prognosis.

STAT3 is a critical cell-intrinsic regulator of human unconventional T cell numbers and function

Wilson et al. show that individuals with loss-of-function mutations in STAT3 have reduced numbers of peripheral blood MAIT and NKT cells, but not γδ T cells. Residual MAIT cells had normal expression of RORγt, but displayed impaired secretion of IL-17A and IL-17F.

Unconventional T cells such as γδ T cells, natural killer T cells (NKT cells) and mucosal-associated invariant T cells (MAIT cells) are a major component of the immune system; however, the cytokine signaling pathways that control their development and function in humans are unknown. Primary immunodeficiencies caused by single gene mutations provide a unique opportunity to investigate the role of specific molecules in regulating human lymphocyte development and function. We found that individuals with loss-of-function mutations in STAT3 had reduced numbers of peripheral blood MAIT and NKT but not γδ T cells. Analysis of STAT3 mosaic individuals revealed that this effect was cell intrinsic. Surprisingly, the residual STAT3-deficient MAIT cells expressed normal levels of the transcription factor RORγt. Despite this, they displayed a deficiency in secretion of IL-17A and IL-17F, but were able to secrete normal levels of cytokines such as IFNγ and TNF. The deficiency in MAIT and NKT cells in STAT3-deficient patients was mirrored by loss-of-function mutations in IL12RB1 and IL21R, respectively. Thus, these results reveal for the first time the essential role of STAT3 signaling downstream of IL-23R and IL-21R in controlling human MAIT and NKT cell numbers.

The extended clinical phenotype of 64 patients with dedicator of cytokinesis 8 deficiency

BACKGROUND

Mutations in dedicator of cytokinesis 8 (DOCK8) cause a combined immunodeficiency (CID) also classified as autosomal recessive (AR) hyper-IgE syndrome (HIES). Recognizing patients with CID/HIES is of clinical importance because of the difference in prognosis and management.

OBJECTIVES

We sought to define the clinical features that distinguish DOCK8 deficiency from other forms of HIES and CIDs, study the mutational spectrum of DOCK8 deficiency, and report on the frequency of specific clinical findings.

METHODS

Eighty-two patients from 60 families with CID and the phenotype of AR-HIES with (64 patients) and without (18 patients) DOCK8 mutations were studied. Support vector machines were used to compare clinical data from 35 patients with DOCK8 deficiency with those from 10 patients with AR-HIES without a DOCK8 mutation and 64 patients with signal transducer and activator of transcription 3 (STAT3) mutations.

RESULTS

DOCK8-deficient patients had median IgE levels of 5201 IU, high eosinophil levels of usually at least 800/μL (92% of patients), and low IgM levels (62%). About 20% of patients were lymphopenic, mainly because of low CD4(+) and CD8(+) T-cell counts. Fewer than half of the patients tested produced normal specific antibody responses to recall antigens. Bacterial (84%), viral (78%), and fungal (70%) infections were frequently observed. Skin abscesses (60%) and allergies (73%) were common clinical problems. In contrast to STAT3 deficiency, there were few pneumatoceles, bone fractures, and teething problems. Mortality was high (34%). A combination of 5 clinical features was helpful in distinguishing patients with DOCK8 mutations from those with STAT3 mutations.

CONCLUSIONS

DOCK8 deficiency is likely in patients with severe viral infections, allergies, and/or low IgM levels who have a diagnosis of HIES plus hypereosinophilia and upper respiratory tract infections in the absence of parenchymal lung abnormalities, retained primary teeth, and minimal trauma fractures.

Matched related and unrelated donor hematopoietic stem cell transplantation for DOCK8 deficiency

We performed allogeneic hematopoietic stem cell transplantation in 6 patients with mutations in the dedicator-of-cytokinesis-8 (DOCK8) gene using a myeloablative conditioning regimen consisting of busulfan 3.2 mg/kg/day i.v. for 4 days and fludarabine 40 mg/m(2)/day for 4 days. Three patients received allografts from matched related donors and 3 patients from matched unrelated donors. Two patients received peripheral blood stem cells and 4 patients bone marrow hematopoietic stem cells. Tacrolimus and short-course methotrexate on days 1, 3, 6, and 11 were used for graft-versus-host-disease (GVHD) prophylaxis. All 6 patients are alive at a median follow-up of 22.5 months (range, 14 to 35). All patients achieved rapid and high levels of donor engraftment and complete reversal of the clinical and immunologic phenotype. Adverse events consisted of acute skin GVHD in 2 patients and post-transplant pulmonary infiltrates in a patient with extensive bronchiectasis pretransplant. Thus, a uniform myeloablative conditioning regimen followed by allogeneic hematopoietic stem cell transplantation in DOCK8 deficiency results in reconstitution of immunologic function and reversal of the clinical phenotype with a low incidence of regimen-related toxicity.

Common severe infections in chronic granulomatous disease

BACKGROUND

Chronic granulomatous disease (CGD) is due to defective nicotinamide adenine dinucleotide phosphate oxidase activity and characterized by recurrent infections with a limited spectrum of bacteria and fungi as well as inflammatory complications. To understand the impact of common severe infections in CGD, we examined the records of 268 patients followed at a single center over 4 decades.

METHODS

All patients had confirmed diagnoses of CGD, and genotype was determined where possible. Medical records were excerpted into a standard format. Microbiologic analyses were restricted to Staphylococcus, Burkholderia, Serratia, Nocardia, and Aspergillus.

RESULTS

Aspergillus incidence was estimated at 2.6 cases per 100 patient-years; Burkholderia, 1.06 per 100 patient-years; Nocardia, 0.81 per 100 patient-years; Serratia, 0.98 per 100 patient-years, and severe Staphylococcus infection, 1.44 per 100 patient-years. Lung infection occurred in 87% of patients, whereas liver abscess occurred in 32%. Aspergillus incidence was 55% in the lower superoxide-producing quartiles (quartiles 1 and 2) but only 41% in the higher quartiles (rate ratio, <0.0001). Aspergillus and Serratia were somewhat more common in lower superoxide producing gp91phox deficiency. The median age at death has increased from 15.53 years before 1990 to 28.12 years in the last decade. Fungal infection carried a higher risk of mortality than bacterial infection and was the most common cause of death (55%). Gastrointestinal complications were not associated with either infection or mortality.

CONCLUSIONS

Fungal infections remain a major determinant of survival in CGD. X-linked patients generally had more severe disease, and this was generally in those with lower residual superoxide production. Survival in CGD has increased over the years, but infections are still major causes of morbidity and mortality.

A 17-year old patient with DOCK8 deficiency, severe oral HSV-1 and aggressive periodontitis - a case of virally induced periodontitis?

We present a 17-year old girl with DOCK-8 deficiency, severe untreated oral HSV-1 infection and associated aggressive periodontitis. DOCK-8 deficiency is a primary immunodeficiency, caused by biallelicloss-of-function mutations in the DOCK8 gene, often leading to severe viral and fungal mucocutaneous infections. Nevertheless, to date DOCK8 has not been associated with severe periodontitis and inflammatory bone loss around teeth. Understanding whether DOCK8 deficiency or severe HSV-1 infection underlies susceptibility to periodontitis is central to this case and may provide insights into susceptibility factors for periodontitis in the general population. Our clinical and microbiological data suggest that severe HSV-1 infection is the driver of periodontal inflammation in this case.

DOCK8 regulates lymphocyte shape integrity for skin antiviral immunity

Zhang et al. show that DOCK8-deficient T and NK cells develop cell and nuclear shape abnormalities that do not impair chemotaxis but contribute to a form of cell death they term cytothripsis. Cytothripsis of DOCK8-deficient cells prevents the generation of long-lived skin-resident memory CD8 T cells resulting in impaired immune response to skin infection.

DOCK8 mutations result in an inherited combined immunodeficiency characterized by increased susceptibility to skin and other infections. We show that when DOCK8-deficient T and NK cells migrate through confined spaces, they develop cell shape and nuclear deformation abnormalities that do not impair chemotaxis but contribute to a distinct form of catastrophic cell death we term cytothripsis. Such defects arise during lymphocyte migration in collagen-dense tissues when DOCK8, through CDC42 and p21-activated kinase (PAK), is unavailable to coordinate cytoskeletal structures. Cytothripsis of DOCK8-deficient cells prevents the generation of long-lived skin-resident memory CD8 T cells, which in turn impairs control of herpesvirus skin infections. Our results establish that DOCK8-regulated shape integrity of lymphocytes prevents cytothripsis and promotes antiviral immunity in the skin.

Somatic reversion in dedicator of cytokinesis 8 immunodeficiency modulates disease phenotype

BACKGROUND

Autosomal recessive loss-of-function mutations in dedicator of cytokinesis 8 (DOCK8) cause a combined immunodeficiency characterized by atopy, recurrent infections, and cancer susceptibility. A genotype-phenotype explanation for the variable disease expression is lacking.

OBJECTIVE

We investigated whether reversions contributed to the variable disease expression.

METHODS

Patients followed at the National Institutes of Health's Clinical Center were studied. We performed detailed genetic analyses and intracellular flow cytometry to detect DOCK8 protein expression within lymphocyte subsets.

RESULTS

We identified 17 of 34 DOCK8-deficient patients who had germline mutations with variable degrees of reversion caused by somatic repair. Somatic repair of the DOCK8 mutations resulted from second-site mutation, original-site mutation, gene conversion, and intragenic crossover. Higher degrees of reversion were associated with recombination-mediated repair. DOCK8 expression was restored primarily within antigen-experienced T cells or natural killer cells but less so in naive T or B cells. Several patients exhibited multiple different repair events. Patients who had reversions were older and had less severe allergic disease, although infection susceptibility persisted. No patients were cured without hematopoietic cell transplantation.

CONCLUSIONS

In patients with DOCK8 deficiency, only certain combinations of germline mutations supported secondary somatic repair. Those patients had an ameliorated disease course with longer survival but still had fatal complications or required hematopoietic cell transplantation. These observations support the concept that some DOCK8-immunodeficient patients have mutable mosaic genomes that can modulate disease phenotype over time.

Autosomal recessive phosphoglucomutase 3 (PGM3) mutations link glycosylation defects to atopy, immune deficiency, autoimmunity, and neurocognitive impairment

BACKGROUND

Identifying genetic syndromes that lead to significant atopic disease can open new pathways for investigation and intervention in allergy.

OBJECTIVE

We sought to define a genetic syndrome of severe atopy, increased serum IgE levels, immune deficiency, autoimmunity, and motor and neurocognitive impairment.

METHODS

Eight patients from 2 families with similar syndromic features were studied. Thorough clinical evaluations, including brain magnetic resonance imaging and sensory evoked potentials, were performed. Peripheral lymphocyte flow cytometry, antibody responses, and T-cell cytokine production were measured. Whole-exome sequencing was performed to identify disease-causing mutations. Immunoblotting, quantitative RT-PCR, enzymatic assays, nucleotide sugar, and sugar phosphate analyses, along with matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry of glycans, were used to determine the molecular consequences of the mutations.

RESULTS

Marked atopy and autoimmunity were associated with increased T(H)2 and T(H)17 cytokine production by CD4(+) T cells. Bacterial and viral infection susceptibility were noted along with T-cell lymphopenia, particularly of CD8(+) T cells, and reduced memory B-cell numbers. Apparent brain hypomyelination resulted in markedly delayed evoked potentials and likely contributed to neurologic abnormalities. Disease segregated with novel autosomal recessive mutations in a single gene, phosphoglucomutase 3 (PGM3). Although PGM3 protein expression was variably diminished, impaired function was demonstrated by decreased enzyme activity and reduced uridine diphosphate-N-acetyl-D-glucosamine, along with decreased O- and N-linked protein glycosylation in patients' cells. These results define a new congenital disorder of glycosylation.

CONCLUSIONS

Autosomal recessive hypomorphic PGM3 mutations underlie a disorder of severe atopy, immune deficiency, autoimmunity, intellectual disability, and hypomyelination.