B cells in the pneumococcus-infected lung are heterogeneous and require CD4+ T cell help including CD40L to become resident memory B cells.

Recovery from respiratory pneumococcal infections generates lung-localized protection against heterotypic bacteria, mediated by resident memory lymphocytes. Optimal protection in mice requires re-exposure to pneumococcus within days of initial infection. Serial surface marker phenotyping of B cell populations in a model of pneumococcal heterotypic immunity revealed that bacterial re-exposure stimulates the immediate accumulation of dynamic and heterogeneous populations of B cells in the lung, and is essential for the establishment of lung resident memory B (BRM) cells. The B cells in the early wave were activated, proliferating locally, and associated with both CD4+ T cells and CXCL13. Antagonist- and antibody-mediated interventions were implemented during this early timeframe to demonstrate that lymphocyte recirculation, CD4+ cells, and CD40 ligand (CD40L) signaling were all needed for lung BRM cell establishment, whereas CXCL13 signaling was not. While most prominent as aggregates in the loose connective tissue of bronchovascular bundles, morphometry and live lung imaging analyses showed that lung BRM cells were equally numerous as single cells dispersed throughout the alveolar septae. We propose that CD40L signaling from antigen-stimulated CD4+ T cells in the infected lung is critical to establishment of local BRM cells, which subsequently protect the airways and parenchyma against future potential infections.

Diagnostic testing for interstitial lung disease in common variable immunodeficiency: a systematic review.

Introduction: Common variable immunodeficiency related interstitial lung disease (CVID-ILD, also referred to as GLILD) is generally considered a manifestation of systemic immune dysregulation occurring in up to 20% of people with CVID. There is a lack of evidence-based guidelines for the diagnosis and management of CVID-ILD. Aim: To systematically review use of diagnostic tests for assessing patients with CVID for possible ILD, and to evaluate their utility and risks. Methods: EMBASE, MEDLINE, PubMed and Cochrane databases were searched. Papers reporting information on the diagnosis of ILD in patients with CVID were included. Results: 58 studies were included. Radiology was the investigation modality most commonly used. HRCT was the most reported test, as abnormal radiology often first raised suspicion of CVID-ILD. Lung biopsy was used in 42 (72%) of studies, and surgical lung biopsy had more conclusive results compared to trans-bronchial biopsy (TBB). Analysis of broncho-alveolar lavage was reported in 24 (41%) studies, primarily to exclude infection. Pulmonary function tests, most commonly gas transfer, were widely used. However, results varied from normal to severely impaired, typically with a restrictive pattern and reduced gas transfer. Conclusion: Consensus diagnostic criteria are urgently required to support accurate assessment and monitoring in CVID-ILD. ESID and the ERS e-GLILDnet CRC have initiated a diagnostic and management guideline through international collaboration. Systematic review registration: https://www.crd.york.ac.uk/prospero/, identifier CRD42022276337.

B cells promote granulomatous inflammation during chronic Mycobacterium tuberculosis infection in mice.

The current study reveals that in chronic TB, the B cell-deficient µMT strain, relative to wild-type (WT) C57BL/6 mice, displays in the lungs lower levels of inflammation that are associated with decreased CD4+ T cell proliferation, diminished Th1 response, and enhanced levels of interleukin (IL)-10. The latter result raises the possibility that B cells may restrict lung expression of IL-10 in chronic TB. These observations are recapitulated in WT mice depleted for B cells using anti-CD20 antibodies. IL-10 receptor (IL-10R) blockade reverses the phenotypes of decreased inflammation and attenuated CD4+ T cell responses in B cell-depleted mice. Together, these results suggest that in chronic murine TB, B cells, by virtue of their capacity to restrict expression of the anti-inflammatory and immunosuppressive IL-10 in the lungs, promote the development of a robust protective Th1 response, thereby optimizing anti-TB immunity. This vigorous Th1 immunity and restricted IL-10 expression may, however, allow the development of inflammation to a level that can be detrimental to the host. Indeed, decreased lung inflammation observed in chronically infected B cell-deficient mice, which exhibit augmented lung IL-10 levels, is associated with a survival advantage relative to WT animals. Collectively, the results reveal that in chronic murine TB, B cells play a role in modulating the protective Th1 immunity and the anti-inflammatory IL-10 response, which results in augmentation of lung inflammation that can be host-detrimental. Intriguingly, in tuberculous human lungs, conspicuous B cell aggregates are present in close proximity to tissue-damaging lesions manifesting necrosis and cavitation, suggesting the possibility that in human TB, B cells may contribute to the development of exacerbated pathology that is known to promote transmission. Since transmission is a major hindrance to TB control, investigating into whether B cells can shape the development of severe pulmonic pathological responses in tuberculous individuals is warranted.

Genomic characterization of lymphomas in patients with inborn errors of immunity.

Patients with inborn errors of immunity (IEI) have a higher risk of developing cancer, especially lymphoma. However, the molecular basis for IEI-related lymphoma is complex and remains elusive. Here, we perform an in-depth analysis of lymphoma genomes derived from 23 IEI patients. We identified and validated disease-causing or -associated germline mutations in 14 of 23 patients involving ATM, BACH2, BLM, CD70, G6PD, NBN, PIK3CD, PTEN, and TNFRSF13B. Furthermore, we profiled somatic mutations in the lymphoma genome and identified 8 genes that were mutated at a significantly higher level in IEI-associated diffuse large B-cell lymphomas (DLBCLs) than in non-IEI DLBCLs, such as BRCA2, NCOR1, KLF2, FAS, CCND3, and BRWD3. The latter, BRWD3, is furthermore preferentially mutated in tumors of a subgroup of activated phosphoinositide 3-kinase δ syndrome patients. We also identified 5 genomic mutational signatures, including 2 DNA repair deficiency-related signatures, in IEI-associated lymphomas and a strikingly high number of inter- and intrachromosomal structural variants in the tumor genome of a Bloom syndrome patient. In summary, our comprehensive genomic characterization of lymphomas derived from patients with rare genetic disorders expands our understanding of lymphomagenesis and provides new insights for targeted therapy.

State-of-the-art diagnostic evaluation of common variable immunodeficiency.

OBJECTIVE: To summarize the current understanding of diagnostic and postdiagnostic evaluation of common variable immunodeficiency (CVID). DATA SOURCES: PubMed Central database. STUDY SELECTIONS: Original research articles and review articles from 2015 to 2020 including seminal articles that shaped the diagnostic and postdiagnostic evaluation of CVID were incorporated. This work focuses on initial diagnosis of CVID, genetic evaluations, and postdiagnostic assessment of respiratory, gastrointestinal, and hepatobiliary diseases including spleen and lymph node enlargement. RESULTS: CVID presents not only with frequent infections but also with noninfectious complications such as autoimmunity, gastrointestinal disease, chronic lung disease, granulomas, liver disease, lymphoid hyperplasia, splenomegaly, or malignancy. The risk of morbidity and mortality is higher in patients with CVID and noninfectious complications. Detailed diagnostic approaches, which may incorporate genetic testing, can aid characterization of individual CVID cases and shape treatment in some instances. Moreover, continued evaluation after CVID diagnosis is key to optimal management of this complex disorder. These postdiagnostic evaluations include pulmonary function testing, radiologic studies, and laboratory evaluations that may be conducted at frequencies determined by disease activity. CONCLUSION: Although the diagnosis can be achieved similarly in all patients with CVID, those with noninfectious complications have distinct concerns during clinical evaluation. State-of-the-art workup of CVID with noninfectious complications typically includes genetic analysis, which may shape precision therapy, and thoughtful application of postdiagnostic tests that monitor the presence and progression of disease in the myriad of tissues that may be affected. Even with recent advancements, knowledge gaps in diagnosis, prognosis, and treatment of CVID persist, and continued research efforts are needed.

Safety and Tolerability of Manual Push Administration of Subcutaneous IgPro20 at High Infusion Rates in Patients with Primary Immunodeficiency: Findings from the Manual Push Administration Cohort of the HILO Study.

PURPOSE: To evaluate the safety and tolerability of IgPro20 manual push (also known as rapid push) infusions at flow rates of 0.5-2.0 mL/min. METHODS: Patients with primary immunodeficiency (PID) with previous experience administering IgPro20 (Hizentra®, CSL Behring, King of Prussia, PA, USA) were enrolled in the Hizentra® Label Optimization (HILO) study (NCT03033745) and assigned to Pump-assisted Volume Cohort, Pump-assisted Flow Rate Cohort, or Manual Push Flow Rate Cohort; this report describes the latter. Patients administered IgPro20 via manual push at 0.5, 1.0, and 2.0 mL/min/site for 4 weeks each. Responder rates (percentage of patients who completed a predefined minimum number of infusions), safety outcomes, and serum immunoglobulin G (IgG) trough levels were evaluated. RESULTS: Sixteen patients were treated; 2 patients (12.5%) discontinued at the 1.0-mL/min level (unrelated to treatment). Responder rates were 100%, 100%, and 87.5% at 0.5-, 1.0-, and 2.0-mL/min flow rates, respectively. Mean weekly infusion duration decreased from 103-108 to 23-28 min at the 0.5- and 2.0-mL/min flow rates, respectively. Rates of treatment-related treatment-emergent adverse events (TEAEs) per infusion were 0.023, 0.082, and 0.025 for the 0.5-, 1.0-, and 2.0-mL/min flow rates, respectively. Most TEAEs were mild local reactions and tolerability (infusions without severe local reactions/total infusions) was 100% across flow rate levels. Serum IgG levels (mean [SD]) were similar at study start (9.36 [2.53] g/L) and end (9.58 [2.12] g/L). CONCLUSIONS: Subcutaneous IgPro20 manual push infusions at flow rates up to 2.0 mL/min were well tolerated and reduced infusion time in treatment-experienced patients with PID. TRIAL REGISTRATION: NCT03033745.

B Cell Dysregulation in Common Variable Immunodeficiency Interstitial Lung Disease.

Common variable immunodeficiency (CVID) is the most frequently diagnosed primary antibody deficiency. About half of CVID patients develop chronic non-infectious complications thought to be due to intrinsic immune dysregulation, including autoimmunity, gastrointestinal disease, and interstitial lung disease (ILD). Multiple studies have found ILD to be a significant cause of morbidity and mortality in CVID. Yet, the precise mechanisms underlying this complication in CVID are poorly understood. CVID ILD is marked by profound pulmonary infiltration of both T and B cells as well as granulomatous inflammation in many cases. B cell depletive therapy, whether done as a monotherapy or in combination with another immunosuppressive agent, has become a standard of therapy for CVID ILD. However, CVID is a heterogeneous disorder, as is its lung pathology, and the precise patients that would benefit from B cell depletive therapy, when it should administered, and how long it should be repeated all remain gaps in our knowledge. Moreover, some have ILD recurrence after B cell depletive therapy and the relative importance of B cell biology remains incompletely defined. Developmental and functional abnormalities of B cell compartments observed in CVID ILD and related conditions suggest that imbalance of B cell signaling networks may promote lung disease. Included within these potential mechanisms of disease is B cell activating factor (BAFF), a cytokine that is upregulated by the interferon gamma (IFN-γ):STAT1 signaling axis to potently influence B cell activation and survival. B cell responses to BAFF are shaped by the divergent effects and expression patterns of its three receptors: BAFF receptor (BAFF-R), transmembrane activator and CAML interactor (TACI), and B cell maturation antigen (BCMA). Moreover, soluble forms of BAFF-R, TACI, and BCMA exist and may further influence the pathogenesis of ILD. Continued efforts to understand how dysregulated B cell biology promotes ILD development and progression will help close the gap in our understanding of how to best diagnose, define, and manage ILD in CVID.

Serum B-Cell Maturation Antigen (BCMA) Levels Differentiate Primary Antibody Deficiencies.

BACKGROUND: Primary antibody deficiencies (PADs) are the most prevalent primary immunodeficiencies. More severe forms of PADs-common variable immunodeficiency (CVID) and X-linked agammaglobulinemia (XLA)-require immunoglobulin replacement therapy (IRT) and may have serious complications. Differentiating severe PAD from milder hypogammaglobulinemia not requiring IRT can involve prolonged evaluations and treatment discontinuation. Severe PAD is defined by plasma cell deficiency, but this requires a biopsy to establish. Serum B-cell maturation antigen (sBCMA) is elevated in multiple myeloma, but levels are reduced among patients with myeloma in remission who have hypogammaglobulinemia. OBJECTIVE: To measure the sBCMA level in 165 subjects to determine whether it differentiates severe PAD-CVID and XLA-from less severe forms not requiring IRT and those without PAD. METHODS: sBCMA, B cells, and tissue plasma cells were measured among subjects with and without PAD, and correlated to clinical and laboratory data. RESULTS: Subjects with an IgG level of less than 600 mg/dL had reduced sBCMA levels compared with subjects with PAD with IgG levels of greater than or equal to 600 mg/dL and controls without PAD. sBCMA level was lower in patients with CVID and XLA compared with patients with IgA or IgG deficiency and controls. sBCMA level correlated with gastrointestinal plasma cells. sBCMA level of less than 15 ng/mL had 97% positive predictive value for CVID or XLA, whereas 25 ng/mL or more had an 88% negative predictive value. CONCLUSIONS: sBCMA level is profoundly reduced in patients with severe PAD, including those with CVID and XLA and those with IgG levels of less than 600 mg/dL. sBCMA level measurement has potential to augment clinical evaluation of PAD. Prospective studies are needed to evaluate sBCMA for new PAD diagnosis and determine the necessity of IRT.

BAFF-driven B cell hyperplasia underlies lung disease in common variable immunodeficiency.

BACKGROUND: Common variable immunodeficiency (CVID) is the most common symptomatic primary immunodeficiency and is frequently complicated by interstitial lung disease (ILD) for which etiology is unknown and therapy inadequate. METHODS: Medical record review implicated B cell dysregulation in CVID ILD progression. This was further studied in blood and lung samples using culture, cytometry, ELISA, and histology. Eleven CVID ILD patients were treated with rituximab and followed for 18 months. RESULTS: Serum IgM increased in conjunction with ILD progression, a finding that reflected the extent of IgM production within B cell follicles in lung parenchyma. Targeting these pulmonary B cell follicles with rituximab ameliorated CVID ILD, but disease recurred in association with IgM elevation. Searching for a stimulus of this pulmonary B cell hyperplasia, we found B cell-activating factor (BAFF) increased in blood and lungs of progressive and post-rituximab CVID ILD patients and detected elevation of BAFF-producing monocytes in progressive ILD. This elevated BAFF interacts with naive B cells, as they are the predominant subset in progressive CVID ILD, expressing BAFF receptor (BAFF-R) within pulmonary B cell follicles and blood to promote Bcl-2 expression. Antiapoptotic Bcl-2 was linked with exclusion of apoptosis from B cell follicles in CVID ILD and increased survival of naive CVID B cells cultured with BAFF. CONCLUSION: CVID ILD is driven by pulmonary B cell hyperplasia that is reflected by serum IgM elevation, ameliorated by rituximab, and bolstered by elevated BAFF-mediated apoptosis resistance via BAFF-R. FUNDING: NIH, Primary Immune Deficiency Treatment Consortium, and Rare Disease Foundation.

Differentiation of Common Variable Immunodeficiency From IgG Deficiency.

BACKGROUND: Common variable immunodeficiency (CVID) and IgG deficiency are 2 of the more prevalent primary humoral immune defects. The former is defined by consensus with criteria for quantitative and qualitative antibody defects, whereas the latter is used to describe patients with reduced IgG, who commonly have recurrent sinopulmonary infections but do not fulfill CVID criteria. However, these patients are often given this diagnosis. OBJECTIVE: To compare immunologic findings and clinical manifestations of 2 large cohorts of patients with CVID or IgG deficiency to better delineate differences between these syndromes. METHODS: We extracted clinical and laboratory data from electronic medical records of patients at our institution who had received International Classification of Disease codes for either CVID, or IgG deficiency. We gathered immunoglobulin levels, lymphocyte subpopulation counts, and serological vaccine responses. In some patients, we performed flow cytometry to determine percentages of memory and switched-memory B cells. We compiled and statistically compared clinical data related to infectious manifestations, bronchiectasis, autoimmune diseases, infiltrative inflammatory processes, and lymphoid malignancies. RESULTS: In contrast to IgG-deficient patients, we found that patients with CVID had lower IgG levels, greater unresponsiveness to most vaccines, lower percentages of memory and isotype switched-memory B cells, and lower CD4 T-cell counts. Clinically, patients with CVID presented similar rates of sinusitis and pneumonias, but a significantly higher prevalence of bronchiectasis and especially noninfectious complications. CONCLUSIONS: CVID and IgG deficiency do not share the same disease spectrum, the former being associated with immunodysregulative manifestations and markers of a more severe immune defect. These data may allow clinicians to distinguish these conditions and the management differences that these patients pose.

Patients with common variable immunodeficiency with autoimmune cytopenias exhibit hyperplastic yet inefficient germinal center responses.

BACKGROUND: The lack of pathogen-protective, isotype-switched antibodies in patients with common variable immunodeficiency (CVID) suggests germinal center (GC) hypoplasia, yet a subset of patients with CVID is paradoxically affected by autoantibody-mediated autoimmune cytopenias (AICs) and lymphadenopathy. OBJECTIVE: We sought to compare the physical characteristics and immunologic output of GC responses in patients with CVID with AIC (CVID+AIC) and without AIC (CVID-AIC). METHODS: We analyzed GC size and shape in excisional lymph node biopsy specimens from 14 patients with CVID+AIC and 4 patients with CVID-AIC. Using paired peripheral blood samples, we determined how AICs specifically affected B-and T-cell compartments and antibody responses in patients with CVID. RESULTS: We found that patients with CVID+AIC displayed irregularly shaped hyperplastic GCs, whereas GCs were scarce and small in patients with CVID-AIC. GC hyperplasia was also evidenced by an increase in numbers of circulating follicular helper T cells, which correlated with decreased regulatory T-cell frequencies and function. In addition, patients with CVID+AIC had serum endotoxemia associated with a dearth of isotype-switched memory B cells that displayed significantly lower somatic hypermutation frequencies than their counterparts with CVID-AIC. Moreover, IgG+ B cells from patients with CVID+AIC expressed VH4-34-encoded antibodies with unmutated Ala-Val-Tyr and Asn-His-Ser motifs, which recognize both erythrocyte I/i self-antigens and commensal bacteria. CONCLUSIONS: Patients with CVID+AIC do not contain mucosal microbiota and exhibit hyperplastic yet inefficient GC responses that favor the production of untolerized IgG+ B-cell clones that recognize both commensal bacteria and hematopoietic I/i self-antigens.

Lung Disease in Primary Antibody Deficiencies.

Primary antibody deficiencies (PADs) are the most common form of primary immunodeficiency and predispose to severe and recurrent pulmonary infections, which can result in chronic lung disease including bronchiectasis. Chronic lung disease is among the most common complications of PAD and a significant source of morbidity and mortality for these patients. However, the development of lung disease in PAD may not be solely the result of recurrent bacterial infection or a consequence of bronchiectasis. Recent characterization of monogenic immune dysregulation disorders and more extensive study of common variable immunodeficiency have demonstrated that interstitial lung disease (ILD) in PAD can result from generalized immune dysregulation and frequently occurs in the absence of pneumonia history or bronchiectasis. This distinction between bronchiectasis and ILD has important consequences in the evaluation and management of lung disease in PAD. For example, treatment of ILD in PAD typically uses immunomodulatory approaches in addition to immunoglobulin replacement and antibiotic prophylaxis, which are the stalwarts of bronchiectasis management in these patients. Although all antibody-deficient patients are at risk of developing bronchiectasis, ILD occurs in some forms of PAD much more commonly than in others, suggesting that distinct but poorly understood immunological factors underlie the development of this complication. Importantly, ILD can have earlier onset and may worsen survival more than bronchiectasis. Further efforts to understand the pathogenesis of lung disease in PAD will provide vital information for the most effective methods of diagnosis, surveillance, and treatment of these patients.

Autoimmune and Lymphoproliferative Complications of Common Variable Immunodeficiency.

Common variable immunodeficiency (CVID) is frequently complicated by the development of autoimmune and lymphoproliferative diseases. With widespread use of immunoglobulin replacement therapy, autoimmune and lymphoproliferative complications have replaced infection as the major cause of morbidity and mortality in CVID patients. Certain CVID complications, such as bronchiectasis, are likely to be the result of immunodeficiency and are associated with infection susceptibility. However, other complications may result from immune dysregulation rather than immunocompromise. CVID patients develop autoimmunity, lymphoproliferation, and granulomas in association with distinct immunological abnormalities. Mutations in transmembrane activator and CAML interactor, reduction of isotype-switched memory B cells, expansion of CD21 low B cells, heightened interferon signature expression, and retained B cell function are all associated with both autoimmunity and lymphoproliferation in CVID. Further research aimed to better understand that the pathological mechanisms of these shared forms of immune dysregulation may inspire therapies beneficial for multiple CVID complications.

Expansion of inflammatory innate lymphoid cells in patients with common variable immune deficiency.

BACKGROUND: Common variable immunodeficiency (CVID) is an antibody deficiency treated with immunoglobulin; however, patients can have noninfectious inflammatory conditions that lead to heightened morbidity and mortality. OBJECTIVES: Modular analyses of RNA transcripts in whole blood previously identified an upregulation of many interferon-responsive genes. In this study we sought the cell populations leading to this signature. METHODS: Lymphoid cells were measured in peripheral blood of 55 patients with CVID (31 with and 24 without inflammatory/autoimmune complications) by using mass cytometry and flow cytometry. Surface markers, cytokines, and transcriptional characteristics of sorted innate lymphoid cells (ILCs) were defined by using quantitative PCR. Gastrointestinal and lung biopsy specimens of subjects with inflammatory disease were stained to seek ILCs in tissues. RESULTS: The linage-negative, CD127(+), CD161(+) lymphoid population containing T-box transcription factor, retinoic acid-related orphan receptor (ROR) γt, IFN-γ, IL-17A, and IL-22, all hallmarks of type 3 innate lymphoid cells, were expanded in the blood of patients with CVID with inflammatory conditions (mean, 3.7% of PBMCs). ILCs contained detectable amounts of the transcription factors inhibitor of DNA binding 2, T-box transcription factor, and RORγt and increased mRNA transcripts for IL-23 receptor (IL-23R) and IL-26, demonstrating inflammatory potential. In gastrointestinal and lung biopsy tissues of patients with CVID, numerous IFN-γ(+)RORγt(+)CD3(-) cells were identified, suggesting a role in these mucosal inflammatory states. CONCLUSIONS: An expansion of this highly inflammatory ILC population is a characteristic of patients with CVID with inflammatory disease; ILCs and the interferon signature are markers for the uncontrolled inflammatory state in these patients.

Progression of Common Variable Immunodeficiency Interstitial Lung Disease Accompanies Distinct Pulmonary and Laboratory Findings.

BACKGROUND: Common variable immunodeficiency may be complicated by interstitial lung disease, which leads to worsened morbidity and mortality in some. Although immunomodulatory treatment has efficacy, choice of patient, duration of treatment, and long-term follow-up are not available. Interstitial lung disease appears stable in certain instances, so it is not known whether all patients will develop progressive disease or require immunomodulatory therapy. OBJECTIVE: This study aims to determine if all common variable immunodeficiency patients with interstitial lung disease have physiological worsening, and if clinical and/or laboratory parameters may correlate with disease progression. METHODS: A retrospective review of medical records at Mount Sinai Medical Center in New York was conducted for referred patients with common variable immunodeficiency, CT scan-confirmed interstitial lung disease, and periodic pulmonary function testing covering 20 or more months before immunomodulatory therapy. Fifteen patients were identified from the retrospective review and included in this study. RESULTS: Of the 15 patients with common variable immunodeficiency, 9 had physiological worsening of interstitial lung disease adapted from consensus guidelines, associated with significant reductions in forced expiratory volume in 1 second, forced vital capacity, and diffusion capacity of the lung for carbon monoxide. Those with progressive lung disease also had significantly lower mean immunoglobulin G levels, greater increases and highest levels of serum immunoglobulin M (IgM), and more significant thrombocytopenia. CONCLUSION: Interstitial lung disease resulted in physiological worsening in many, but not all subjects, and was associated with suboptimal immunoglobulin G replacement. Those with worsening pulmonary function tests, elevated IgM, and severe thrombocytopenic episodes appear to be at highest risk for progressive disease. Such patients may benefit from immunomodulatory treatment.

Toll-like receptor signaling in primary immune deficiencies.

Toll-like receptors (TLRs) recognize common microbial or host-derived macromolecules and have important roles in early activation of the immune system. Patients with primary immune deficiencies (PIDs) affecting TLR signaling can elucidate the importance of these proteins to the human immune system. Defects in interleukin-1 receptor-associated kinase-4 and myeloid differentiation factor 88 (MyD88) lead to susceptibility to infections with bacteria, while mutations in nuclear factor-κB essential modulator (NEMO) and other downstream mediators generally induce broader susceptibility to bacteria, viruses, and fungi. In contrast, TLR3 signaling defects are specific for susceptibility to herpes simplex virus type 1 encephalitis. Other PIDs induce functional alterations of TLR signaling pathways, such as common variable immunodeficiency in which plasmacytoid dendritic cell defects enhance defective responses of B cells to shared TLR agonists. Dampening of TLR responses is seen for TLRs 2 and 4 in chronic granulomatous disease (CGD) and X-linked agammaglobulinemia (XLA). Enhanced TLR responses, meanwhile, are seen for TLRs 5 and 9 in CGD, TLRs 4, 7/8, and 9 in XLA, TLRs 2 and 4 in hyper IgE syndrome, and for most TLRs in adenosine deaminase deficiency.

Pulmonary radiologic findings in common variable immunodeficiency: clinical and immunological correlations.

BACKGROUND: It remains unclear whether interstitial lung disease (ILD) in common variable immunodeficiency (CVID) is a consequence of chronic infection or a manifestation of dysregulated lymphoid proliferation found in those with this condition. OBJECTIVE: To increase understanding of CVID-associated lung disease by comparing clinical and immunologic associations in those with bronchiectasis, ILD, or no lung disease observed on chest computerized tomography (CT). METHODS: Retrospective review of electronic medical records of 61 patients with CVID was used to identify clinical and laboratory correlates of bronchiectasis, ground glass opacity, and pulmonary nodules on CT scan. RESULTS: Significant clinical and immunologic associations were identified for common CT scan findings in CVID. Bronchiectasis was strongly correlated with a CD4+ T-cell count lower than 700 cells/µL and was associated with a history of pneumonia and older age. Pulmonary nodular disease was correlated with increased CD4+:CD8+ T-cell ratios, a history of autoimmune hemolytic anemia or immune thrombocytopenic purpura, elevated IgM, and younger age. Ground glass opacity had similar clinical and laboratory characteristics as those for nodular lung disease but was associated with elevated monocyte counts and the presence of liver disease. CONCLUSION: CT findings of bronchiectasis or ILD, including ground glass opacity and extensive pulmonary nodules, were correlated with selected clinical and laboratory characteristics. These results suggest divergent processes of CVID lung disease, with bronchiectasis more strongly associated with infection and T-cell lymphopenia and ILD more strongly linked with autoimmunity and lymphoproliferation.

Phellinus tropicalis abscesses in a patient with chronic granulomatous disease.

Chronic Granulomatous Disease (CGD), caused by genetic defects in components of the phagocyte NADPH oxidase pathway, leads to recurrent life-threatening bacterial and invasive fungal infections. While a number of unique pathogens have been associated with this disease, the causative organisms may be difficult to identify. Here, we present a 24 year old male with known X-linked CGD who concurrently developed a cervical abscess and an abscess in the subcutaneous tissues of the right hip, both of which were surgically drained. Cultures failed to identify any organisms. He was treated empirically with ertapenem but the hip abscess recurred at the original site and in contiguous dependent areas in the posterior thigh and knee. A filamentous organism was observed microscopically, initially considered a contaminant, but on culture yielded a mold growth, identified as Phellinus tropicalis (synonym: Inonotus tropicalis) based on phenotypic and molecular methods. This is the third case report of human infection with P. tropicalis, all in subjects with CGD. The patient was treated with voriconazole with resolution of his symptoms.