Lymphocyte-driven regional immunopathology in pneumonitis caused by impaired central immune tolerance.

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED), a monogenic disorder caused by AIRE mutations, presents with several autoimmune diseases. Among these, endocrine organ failure is widely recognized, but the prevalence, immunopathogenesis, and treatment of non-endocrine manifestations such as pneumonitis remain poorly characterized. We enrolled 50 patients with APECED in a prospective observational study and comprehensively examined their clinical and radiographic findings, performed pulmonary function tests, and analyzed immunological characteristics in blood, bronchoalveolar lavage fluid, and endobronchial and lung biopsies. Pneumonitis was found in >40% of our patients, presented early in life, was misdiagnosed despite chronic respiratory symptoms and accompanying radiographic and pulmonary function abnormalities, and caused hypoxemic respiratory failure and death. Autoantibodies against BPIFB1 and KCNRG and the homozygous c.967_979del13 AIRE mutation are associated with pneumonitis development. APECED pneumonitis features compartmentalized immunopathology, with accumulation of activated neutrophils in the airways and lymphocytic infiltration in intraepithelial, submucosal, peribronchiolar, and interstitial areas. Beyond APECED, we extend these observations to lung disease seen in other conditions with secondary AIRE deficiency (thymoma and RAG deficiency). Aire-deficient mice had similar compartmentalized cellular immune responses in the airways and lung tissue, which was ameliorated by deficiency of T and B lymphocytes. Accordingly, T and B lymphocyte-directed immunomodulation controlled symptoms and radiographic abnormalities and improved pulmonary function in patients with APECED pneumonitis. Collectively, our findings unveil lung autoimmunity as a common, early, and unrecognized manifestation of APECED and provide insights into the immunopathogenesis and treatment of pulmonary autoimmunity associated with impaired central immune tolerance.

X-linked carriers of chronic granulomatous disease: Illness, lyonization, and stability.

BACKGROUND: Chronic granulomatous disease (CGD) is characterized by recurrent life-threatening bacterial and fungal infections and aberrant inflammation. Mutations in CYBB cause X-linked CGD and account for 65% to 70% of cases in Western countries. OBJECTIVE: We sought to understand the clinical manifestations associated with the X-linked CGD carrier state. METHODS: We undertook a comprehensive retrospective study of 162 affected female subjects. We examined dihydrorhodamine 123 (DHR) oxidation data for percentage of X-chromosome inactivation. We correlated lyonization (%DHR+) with clinical features. Where possible, we followed %DHR+ values over time. RESULTS: Clinical data were available for 93 female subjects: %DHR+ values were 46% (mean) and 47% (median; SD, 24). Using the %DHR+ value as the criterion for X inactivation, 78% of patients had levels of inactivation of 20% to 80%, suggesting random inactivation that was independent of age. In contrast, carriers with CGD-type infections had median %DHR+ values of 8% (n = 14; range, 0.06% to 48%), and those with only autoimmune or inflammatory manifestations had median %DHR+ values of 39% (n = 31; range, 7.4% to 74%). Those with both infections and autoimmunity had low %DHR+ values (n = 6; range, 3% to 14%). A %DHR+ value of less than 10% was strongly associated with infections (odds ratio, 99). Strong association persisted when %DHR+ values were less than 20% (odds ratio, 12). Autoimmunity was not associated with %DHR+ values. In 2 sets of identical twins, the %DHR+ populations tracked closely over time. Although the %DHR+ populations were very similar between sisters, those between mothers and daughters were unrelated. CONCLUSIONS: A low %DHR+ value strongly predicts infection risk in X-linked CGD carriers, and the carrier state itself is associated with autoimmunity.

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.

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.

Bone density and fractures in autosomal dominant hyper IgE syndrome.

PURPOSE: Autosomal Dominant Hyper IgE Recurrent Infection Syndrome (AD-HIES) is caused by mutations in STAT3 and characterized by eczema, recurrent bacterial infections, and skeletal and connective tissue abnormalities. To further understand the minimal trauma fractures of AD-HIES, we examined bone mineral density (BMD) and laboratory markers of bone turnover. METHODS: Patients with AD-HIES enrolled in a prospective natural history study were examined with dual x-ray absorptiometry (DEXA) scans and laboratory studies of bone metabolism. The number of fractures was recorded as well as clinical features of AD-HIES including scoliosis and retained primary teeth. Patients on medications with skeletal effects, including bisphosphonates, were examined separately. RESULTS: Twenty-three AD-HIES children (6-18 years) and 33 AD-HIES adults (21-50 years) not receiving bone-active drugs were studied. Fourteen of the 23 children (61%) had histories of minimal trauma fractures, as did 26 of the 33 adults (79%). Osteopenia or osteoporosis was found in 79% of children and adults. Only radial BMD correlated with the qualitative occurrence of fractures but it did not correlate with the numbers of fractures. Markers of bone metabolism did not correlate with minimal trauma fractures or BMD. Patients on bone-active medications had improved BMD, but still sustained fractures. CONCLUSIONS: Minimal trauma fractures and decreased BMD are common in AD-HIES. Low radial BMD is associated with fractures, but hip and spine BMD are not. Treatment with bisphosphonates increased BMD but its role in fracture prevention remains undefined.

STAT3 mutations in the hyper-IgE syndrome.

BACKGROUND: The hyper-IgE syndrome (or Job's syndrome) is a rare disorder of immunity and connective tissue characterized by dermatitis, boils, cyst-forming pneumonias, elevated serum IgE levels, retained primary dentition, and bone abnormalities. Inheritance is autosomal dominant; sporadic cases are also found. METHODS: We collected longitudinal clinical data on patients with the hyper-IgE syndrome and their families and assayed the levels of cytokines secreted by stimulated leukocytes and the gene expression in resting and stimulated cells. These data implicated the signal transducer and activator of transcription 3 gene (STAT3) as a candidate gene, which we then sequenced. RESULTS: We found increased levels of proinflammatory gene transcripts in unstimulated peripheral-blood neutrophils and mononuclear cells from patients with the hyper-IgE syndrome, as compared with levels in control cells. In vitro cultures of mononuclear cells from patients that were stimulated with lipopolysaccharide, with or without interferon-gamma, had higher tumor necrosis factor alpha levels than did identically treated cells from unaffected persons (P=0.003). In contrast, the cells from patients with the hyper-IgE syndrome generated lower levels of monocyte chemoattractant protein 1 in response to the presence of interleukin-6 (P=0.03), suggesting a defect in interleukin-6 signaling through its downstream mediators, one of which is STAT3. We identified missense mutations and single-codon in-frame deletions in STAT3 in 50 familial and sporadic cases of the hyper-IgE syndrome. Eighteen discrete mutations, five of which were hot spots, were predicted to directly affect the DNA-binding and SRC homology 2 (SH2) domains. CONCLUSIONS: Mutations in STAT3 underlie sporadic and dominant forms of the hyper-IgE syndrome, an immunodeficiency syndrome involving increased innate immune response, recurrent infections, and complex somatic features.

Pneumocystis jiroveci infection in patients with hyper-immunoglobulin E syndrome.

The hyper-immunoglobulin E syndrome is a primary immunodeficiency characterized by recurrent pyogenic skin and lung abscesses, dermatitis, and elevated serum immunoglobulin E levels. Pneumocystis jiroveci (formerly Pneumocystis carinii) is not typically associated with hyper-immunoglobulin E syndrome. We identified 7 patients with hyper-immunoglobulin E syndrome with P. jiroveci detected in respiratory or pulmonary pathology specimens. In 5 patients it was the sole pathogen, and in 2 other patients it contributed to a polymicrobial etiology. No consistent prophylaxis was given, and there have been no recurrences on long-term follow-up. Our experience suggests that P. jiroveci can cause pneumonia in patients with hyper-immunoglobulin E syndrome both with and without chronic lung disease.

Gastrointestinal involvement in chronic granulomatous disease.

OBJECTIVE: Chronic granulomatous disease (CGD) is a rare disorder of phagocyte oxidative metabolism. In addition to infectious complications, granulomatous lesions often involve hollow viscera, especially the gastrointestinal (GI) tract. The objective of this study was to evaluate the clinical presentation, prevalence, and consequences of GI involvement in patients with CGD. METHODS: The medical records of 140 patients with CGD (67% X-linked) followed at the National Institutes of Health were reviewed and abstracted for GI manifestations. All available GI pathology was reviewed. RESULTS: GI involvement was recorded in 46 (32.8%) of 140 patients with CGD, 89% of whom had X-linked inheritance. The median age at the time of initial GI manifestations was 5 years (range: 0.8-30 years); 70% of the affected patients presented with GI involvement in the first decade of life. Abdominal pain was the most frequent symptom (100%), and hypoalbuminemia was the most frequent sign (70%). Prednisone controlled symptoms and signs in the majority of affected patients, but relapse of symptoms occurred in 71%. GI involvement had no effect on mortality and was unassociated with interferon-gamma use. CONCLUSION: GI involvement is a common and recurring problem in CGD, especially in those with X-linked inheritance. Currently, there is no clear evidence for an infectious cause. The frequency of GI involvement is unaffected by the use of interferon-gamma and does not affect mortality. GI involvement should be sought in patients who have CGD with abdominal pain, growth delay, or hypoalbuminemia.