Longitudinal analysis of the lung proteome reveals persistent repair months after mild to moderate COVID-19.

In order to assess homeostatic mechanisms in the lung after COVID-19, changes in the protein signature of bronchoalveolar lavage from 45 patients with mild to moderate disease at three phases (acute, recovery, and convalescent) are evaluated over a year. During the acute phase, inflamed and uninflamed phenotypes are characterized by the expression of tissue repair and host defense response molecules. With recovery, inflammatory and fibrogenic mediators decline and clinical symptoms abate. However, at 9 months, quantified radiographic abnormalities resolve in the majority of patients, and yet compared to healthy persons, all showed ongoing activation of cellular repair processes and depression of the renin-kallikrein-kinin, coagulation, and complement systems. This dissociation of prolonged reparative processes from symptom and radiographic resolution suggests that occult ongoing disruption of the lung proteome is underrecognized and may be relevant to recovery from other serious viral pneumonias.

Visceral Leishmaniasis in Immunocompetent Hosts in Brescia: A Case Series and Analysis of Cytokine Cascade.

Visceral leishmaniasis (VL) is a parasitic zoonosis caused by Leishmania spp. that usually manifests itself in immunocompromised subjects. It is a rare and neglected disease, and it is not endemic in the province of Brescia (Italy). Three cases of human VL occurred in Brescia from October to December 2021 in immunocompetent patients. We evaluated the patients looking for signs of underlying immunodeficiencies and conducted further epidemiological evaluations in the province of Brescia without success. An analysis of the sera levels of the main cytokines involved in the immune response to VL was performed. All patients presented a significant augmentation of CXCL-10, CCL-4, and IL-6. The patients tested during the acute phase showed an elevation of IL-1α, IL-5, IL-10, and IL-12, while in the recovery phase, higher levels of TNF-α and IL-7 were detected. Altogether, a predominant activation of the T-helper-2 pathway emerged during the acute phase of the parasite infection, while the cytokines associated with the T-helper-1 pathway were less represented. This imbalanced immune response to the parasite infection might play a crucial role in the development of VL in immunocompetent patients.

Anakinra-Associated Systemic Amyloidosis.

OBJECTIVE: To describe a 41-year-old woman with a history of neonatal onset multisystem inflammatory disease, on treatment with daily subcutaneous injections of 600 mg of recombinant interleukin-1 receptor antagonist (IL-1Ra) protein, anakinra, since the age of 28, who presented with golf-ball size nodules at the anakinra injection sites, early satiety, new onset nephrotic syndrome in the context of normal markers of systemic inflammation. METHODS: Clinical history and histologic evaluation of biopsies of skin, gastric mucosa, and kidney with Congo-red staining and proteomic evaluation of microdissected Congo red-positive amyloid deposits by liquid chromatography-tandem mass spectrometry. RESULTS: The skin, stomach, and kidney biopsies all showed the presence of Congo red-positive amyloid deposits. Mass spectrometry-based proteomics demonstrated that the amyloid deposits in all sites were of AIL1RAP (IL-1Ra protein)-type. These were characterized by high spectral counts of the amyloid signature proteins (apolipoprotein AIV, apolipoprotein E, and serum amyloid P-component) and the amyloidogenic IL-1Ra protein, which were present in Congo red-positive areas and absent in Congo red-negative areas. The amino acid sequence identified by mass spectrometry confirmed that the amyloid precursor protein was recombinant IL-1Ra (anakinra) and not endogenous wild-type IL-1Ra. CONCLUSION: This is the first report of iatrogenic systemic amyloidosis due to an injectable protein drug, which was caused by recombinant IL1Ra (anakinra).

Characterization of the antispike IgG immune response to COVID-19 vaccines in people with a wide variety of immunodeficiencies.

Research on coronavirus disease 2019 vaccination in immune-deficient/disordered people (IDP) has focused on cancer and organ transplantation populations. In a prospective cohort of 195 IDP and 35 healthy volunteers (HV), antispike immunoglobulin G (IgG) was detected in 88% of IDP after dose 2, increasing to 93% by 6 months after dose 3. Despite high seroconversion, median IgG levels for IDP never surpassed one-third that of HV. IgG binding to Omicron BA.1 was lowest among variants. Angiotensin-converting enzyme 2 pseudo-neutralization only modestly correlated with antispike IgG concentration. IgG levels were not significantly altered by receipt of different messenger RNA-based vaccines, immunomodulating treatments, and prior severe acute respiratory syndrome coronavirus 2 infections. While our data show that three doses of coronavirus disease 2019 vaccinations induce antispike IgG in most IDP, additional doses are needed to increase protection. Because of the notably reduced IgG response to Omicron BA.1, the efficacy of additional vaccinations, including bivalent vaccines, should be studied in this population.

A phase III randomized crossover trial of plerixafor versus G-CSF for treatment of WHIM syndrome.

BACKGROUNDWarts, hypogammaglobulinemia, infections, and myelokathexis (WHIM) syndrome is a primary immunodeficiency disorder caused by heterozygous gain-of-function CXCR4 mutations. Myelokathexis is a kind of neutropenia caused by neutrophil retention in bone marrow and in WHIM syndrome is associated with lymphopenia and monocytopenia. The CXCR4 antagonist plerixafor mobilizes leukocytes to the blood; however, its safety and efficacy in WHIM syndrome are undefined.METHODSIn this investigator-initiated, single-center, quadruple-masked phase III crossover trial, we compared the total infection severity score (TISS) as the primary endpoint in an intent-to-treat manner in 19 patients with WHIM who each received 12 months treatment with plerixafor and 12 months treatment with granulocyte CSF (G-CSF, the standard of care for severe congenital neutropenia). The treatment order was randomized for each patient.RESULTSPlerixafor was nonsuperior to G-CSF for TISS (P = 0.54). In exploratory endpoints, plerixafor was noninferior to G-CSF for maintaining neutrophil counts of more than 500 cells/µL (P = 0.023) and was superior to G-CSF for maintaining lymphocyte counts above 1,000 cells/µL (P < 0.0001). Complete regression of a subset of large wart areas occurred on plerixafor in 5 of 7 patients with major wart burdens at baseline. Transient rash occurred on plerixafor, and bone pain was more common on G-CSF. There were no significant differences in drug preference or quality of life or the incidence of drug failure or serious adverse events.CONCLUSIONPlerixafor was not superior to G-CSF in patients with WHIM for TISS, the primary endpoint. Together with wart regression and hematologic improvement, the infection severity results support continued study of plerixafor as a potential treatment for WHIM syndrome.TRIAL REGISTRATIONClinicaltrials.gov NCT02231879.FUNDINGThis study was funded by the Division of Intramural Research, National Institute of Allergy and Infectious Diseases.

Inherited ARPC5 mutations cause an actinopathy impairing cell motility and disrupting cytokine signaling.

We describe the first cases of germline biallelic null mutations in ARPC5, part of the Arp2/3 actin nucleator complex, in two unrelated patients presenting with recurrent and severe infections, early-onset autoimmunity, inflammation, and dysmorphisms. This defect compromises multiple cell lineages and functions, and when protein expression is reestablished in-vitro, the Arp2/3 complex conformation and functions are rescued. As part of the pathophysiological evaluation, we also show that interleukin (IL)-6 signaling is distinctively impacted in this syndrome. Disruption of IL-6 classical but not trans-signaling highlights their differential roles in the disease and offers perspectives for therapeutic molecular targets.

Hematologically important mutations: Leukocyte adhesion deficiency (second update).

Leukocyte adhesion deficiency (LAD) is an immunodeficiency caused by defects in the adhesion of leukocytes (especially neutrophils) to the blood vessel wall. As a result, patients with LAD suffer from severe bacterial infections and impaired wound healing, accompanied by neutrophilia. In LAD-I, characterized directly after birth by delayed separation of the umbilical cord, mutations are found in ITGB2, the gene that encodes the ß subunit (CD18) of the ß2 integrins. In the rare LAD-II disease, the fucosylation of selectin ligands is disturbed, caused by mutations in SLC35C1, the gene that encodes a GDP-fucose transporter of the Golgi system. LAD-II patients lack the H and Lewis Lea and Leb blood group antigens. Finally, in LAD-III, the conformational activation of the hematopoietically expressed ß integrins is disturbed, leading to leukocyte and platelet dysfunction. This last syndrome is caused by mutations in FERMT3, encoding the kindlin-3 protein in all blood cells, involved in the regulation of ß integrin conformation. This article contains an update of the mutations that we consider to be relevant for the various forms of LAD.

A Heterozygous Gain-of-Function Variant in IKBKB Associated with Autoimmunity and Autoinflammation.

PURPOSE: Biallelic loss-of-function variants in IKBKB cause severe combined immunodeficiency. We describe a case of autoimmunity and autoinflammation in a male infant with a heterozygous gain-of-function (GOF) IKBKB variant. METHODS: Case report and review of the literature. We performed in silico variant analysis, measurement of plasma soluble biomarkers associated with immune activation, functional stimulation of patient peripheral blood mononuclear cells, and functional validation of variants transduced in Jurkat cells. RESULTS: A patient with two heterozygous IKBKB variants (E518K and T559M) presents with previously undescribed autoimmune cytopenias and autoinflammation. He had decreased TNF-α-induced IkBα degradation in vitro, and had increased serum biomarkers associated with macrophage recruitment and activation. Jurkat cells transduced with the IKKb T559M variant showed increased basal levels of phosphorylation of IKKα/b and p65, and higher degradation of IkBα suggesting a GOF mechanism. No significant changes were observed in Jurkat cells transduced with the E518K variant. CONCLUSIONS: A GOF variant in IKBKB may associate with autoinflammation and autoimmunity highlighting a novel clinical phenotype.

Preclinical Evaluation of Foamy Virus Vector-Mediated Gene Addition in Human Hematopoietic Stem/Progenitor Cells for Correction of Leukocyte Adhesion Deficiency Type 1.

Ex vivo gene therapy procedures targeting hematopoietic stem and progenitor cells (HSPCs) predominantly utilize lentivirus-based vectors for gene transfer. We provide the first pre-clinical evidence of the therapeutic utility of a foamy virus vector (FVV) for the genetic correction of human leukocyte adhesion deficiency type 1 (LAD-1), an inherited primary immunodeficiency resulting from mutation of the ß2 integrin common chain, CD18. CD34+ HSPCs isolated from a severely affected LAD-1 patient were transduced under a current good manufacturing practice-compatible protocol with FVV harboring a therapeutic CD18 transgene. LAD-1-associated cellular chemotactic defects were ameliorated in transgene-positive, myeloid-differentiated LAD-1 cells assayed in response to a strong neutrophil chemoattractant in vitro. Xenotransplantation of vector-transduced LAD-1 HSPCs in immunodeficient (NSG) mice resulted in long-term (∼5 months) human cell engraftment within murine bone marrow. Moreover, engrafted LAD-1 myeloid cells displayed in vivo levels of transgene marking previously reported to ameliorate the LAD-1 phenotype in a large animal model of the disease. Vector insertion site analysis revealed a favorable vector integration profile with no overt evidence of genotoxicity. These results coupled with the unique biological features of wild-type foamy virus support the development of FVVs for ex vivo gene therapy of LAD-1.

Immunogenetics associated with severe coccidioidomycosis.

Disseminated coccidioidomycosis (DCM) is caused by Coccidioides, pathogenic fungi endemic to the southwestern United States and Mexico. Illness occurs in approximately 30% of those infected, less than 1% of whom develop disseminated disease. To address why some individuals allow dissemination, we enrolled patients with DCM and performed whole-exome sequencing. In an exploratory set of 67 patients with DCM, 2 had haploinsufficient STAT3 mutations, and defects in ß-glucan sensing and response were seen in 34 of 67 cases. Damaging CLEC7A and PLCG2 variants were associated with impaired production of ß-glucan-stimulated TNF-α from PBMCs compared with healthy controls. Using ancestry-matched controls, damaging CLEC7A and PLCG2 variants were overrepresented in DCM, including CLEC7A Y238* and PLCG2 R268W. A validation cohort of 111 patients with DCM confirmed the PLCG2 R268W, CLEC7A I223S, and CLEC7A Y238* variants. Stimulation with a DECTIN-1 agonist induced DUOX1/DUOXA1-derived hydrogen peroxide [H2O2] in transfected cells. Heterozygous DUOX1 or DUOXA1 variants that impaired H2O2 production were overrepresented in discovery and validation cohorts. Patients with DCM have impaired ß-glucan sensing or response affecting TNF-α and H2O2 production. Impaired Coccidioides recognition and decreased cellular response are associated with disseminated coccidioidomycosis.

Multicenter analysis of neutrophil extracellular trap dysregulation in adult and pediatric COVID-19.

Dysregulation in neutrophil extracellular trap (NET) formation and degradation may play a role in the pathogenesis and severity of COVID-19; however, its role in the pediatric manifestations of this disease, including multisystem inflammatory syndrome in children (MIS-C) and chilblain-like lesions (CLLs), otherwise known as "COVID toes," remains unclear. Studying multinational cohorts, we found that, in CLLs, NETs were significantly increased in serum and skin. There was geographic variability in the prevalence of increased NETs in MIS-C, in association with disease severity. MIS-C and CLL serum samples displayed decreased NET degradation ability, in association with C1q and G-actin or anti-NET antibodies, respectively, but not with genetic variants of DNases. In adult COVID-19, persistent elevations in NETs after disease diagnosis were detected but did not occur in asymptomatic infection. COVID-19-affected adults displayed significant prevalence of impaired NET degradation, in association with anti-DNase1L3, G-actin, and specific disease manifestations, but not with genetic variants of DNases. NETs were detected in many organs of adult patients who died from COVID-19 complications. Infection with the Omicron variant was associated with decreased NET levels when compared with other SARS-CoV-2 strains. These data support a role for NETs in the pathogenesis and severity of COVID-19 in pediatric and adult patients.

Interpretation of Dihydrorhodamine-1,2,3 Flow Cytometry in Chronic Granulomatous Disease: an Atypical Exemplar.

PURPOSE: This is a functional characterization of a novel CYBA variant associated with normal DHR flow cytometry. Chronic granulomatous disease (CGD) is an inborn error of immunity characterized by recurrent bacterial and fungal infections and dysregulated inflammatory responses due to defective phagocytic cell function leading to the formation of granulomas. CGD patients have pathogenic variants in any of the five components of the phagocytic NADPH oxidase, which transfers electrons through the phagosomal membrane and produces superoxide upon bacterial uptake. Here, we report a pediatric female patient with a novel homozygous missense variant (c.293C > T, p.(Ser98Leu)) in CYBA, encoding the p22phox protein, associated with autosomal recessive CGD. METHODS AND RESULTS: The patient presented with severe recurrent pneumonia. Specific pathogens identified included Burkholderia and Serratia species suggesting neutrophil functional abnormalities; however, the dihydrorhodamine-1,2,3 (DHR) flow cytometric and cytochrome c reduction assays for neutrophil respiratory burst fell within the low side of the normal range. Western blot and flow cytometric analysis of individual NADPH oxidase components revealed reduced levels of p22phox and gp91phoxphox proteins. The pathological consequence of the p.Ser98Leu variant was further evaluated in heterologous expression systems, which confirmed reduced p22phox protein stability and oxidase activity. CONCLUSIONS: Although this patient did not exhibit all the classic features of CGD, such as granulomas and skin infections, she had recurrent pneumonias with oxidant-sensitive pathognomonic organisms, resulting in appropriate targeted CGD testing. This case emphasizes the need to contextually interpret laboratory data, especially using clinical findings to direct additional assessments including genetic analysis.

Hematologically important mutations: The autosomal forms of chronic granulomatous disease (third update).

Chronic granulomatous disease (CGD) is an immunodeficiency disorder affecting about 1 in 250,000 individuals. CGD patients suffer from severe, recurrent bacterial and fungal infections. The disease is caused by mutations in the genes encoding the components of the leukocyte NADPH oxidase. This enzyme produces superoxide, which is subsequently metabolized to hydrogen peroxide and other reactive oxygen species (ROS). These products are essential for intracellular killing of pathogens by phagocytic leukocytes (neutrophils, eosinophils, monocytes and macrophages). The leukocyte NADPH oxidase is composed of five subunits, four of which are encoded by autosomal genes. These are CYBA, encoding p22phox, NCF1, encoding p47phox, NCF2, encoding p67phox and NCF4, encoding p40phox. This article lists all mutations identified in these genes in CGD patients. In addition, cytochrome b558 chaperone-1 (CYBC1), recently recognized as an essential chaperone protein for the expression of the X-linked NADPH oxidase component gp91phox (also called Nox2), is encoded by the autosomal gene CYBC1. Mutations in this gene also lead to CGD. Finally, RAC2, a small GTPase of the Rho family, is needed for activation of the NADPH oxidase, and mutations in the RAC2 gene therefore also induce CGD-like symptoms. Mutations in these last two genes are also listed in this article.

Hematologically important mutations: X-linked chronic granulomatous disease (fourth update).

Chronic granulomatous disease (CGD) is an immunodeficiency disorder affecting about 1 in 250,000 individuals. CGD patients suffer from severe bacterial and fungal infections. The disease is caused by a lack of superoxide production by the leukocyte enzyme NADPH oxidase. Superoxide and subsequently formed other reactive oxygen species (ROS) are instrumental in killing phagocytosed micro-organisms in neutrophils, eosinophils, monocytes and macrophages. The leukocyte NADPH oxidase is composed of five subunits, of which the enzymatic component is gp91phox, also called Nox2. This protein is encoded by the CYBB gene on the X chromosome. Mutations in this gene are found in about 70% of all CGD patients in Europe and in about 20% in countries with a high ratio of parental consanguinity. This article lists all mutations identified in CYBB and should therefore help in genetic counseling of X-CGD patients' families. Moreover, apparently benign polymorphisms in CYBB are also given, which should facilitate the recognition of disease-causing mutations. In addition, we also include some mutations in G6PD, the gene on the X chromosome that encodes glucose-6-phosphate dehydrogenase, because inactivity of this enzyme may lead to shortage of NADPH and thus to insufficient activity of NADPH oxidase. Severe G6PD deficiency can induce CGD-like symptoms.

Homozygous variant p. Arg90His in NCF1 is associated with early-onset Interferonopathy: a case report.

BACKGROUND: Biallelic loss-of-function variants in NCF1 lead to reactive oxygen species deficiency and chronic granulomatous disease (CGD). Heterozygosity for the p.Arg90His variant in NCF1 has been associated with susceptibility to systemic lupus erythematosus, rheumatoid arthritis, and Sjögren's syndrome in adult patients. This study demonstrates the association of the homozygous p.Arg90His variant with interferonopathy with features of autoinflammation and autoimmunity in a pediatric patient. CASE PRESENTATION: A 5-year old female of Indian ancestry with early-onset recurrent fever and headache, and persistently elevated antinuclear, anti-Ro, and anti-La antibodies was found to carry the homozygous p.Arg90His variant in NCF1 through exome sequencing. Her unaffected parents and three other siblings were carriers for the mutant allele. Because the presence of two NCF1 pseudogenes, this variant was confirmed by independent genotyping methods. Her intracellular neutrophil oxidative burst and NCF1 expression levels were normal, and no clinical features of CGD were apparent. Gene expression analysis in peripheral blood detected an interferon gene expression signature, which was further supported by cytokine analyses of supernatants of cultured patient's cells. These findings suggested that her inflammatory disease is at least in part mediated by type I interferons. While her fever episodes responded well to systemic steroids, treatment with the JAK inhibitor tofacitinib resulted in decreased serum ferritin levels and reduced frequency of fevers. CONCLUSION: Homozygosity for p.Arg90His in NCF1 should be considered contributory in young patients with an atypical systemic inflammatory antecedent phenotype that may evolve into autoimmunity later in life. The complex genomic organization of NCF1 poses a difficulty for high-throughput genotyping techniques and variants in this gene should be carefully evaluated when using the next generation and Sanger sequencing technologies. The p.Arg90His variant is found at a variable allele frequency in different populations, and is higher in people of South East Asian ancestry. In complex genetic diseases such as SLE, other rare and common susceptibility alleles might be necessary for the full disease expressivity.

SASH3 variants cause a novel form of X-linked combined immunodeficiency with immune dysregulation.

Sterile alpha motif (SAM) and Src homology-3 (SH3) domain-containing 3 (SASH3), also called SH3-containing lymphocyte protein (SLY1), is a putative adaptor protein that is postulated to play an important role in the organization of signaling complexes and propagation of signal transduction cascades in lymphocytes. The SASH3 gene is located on the X-chromosome. Here, we identified 3 novel SASH3 deleterious variants in 4 unrelated male patients with a history of combined immunodeficiency and immune dysregulation that manifested as recurrent sinopulmonary, cutaneous, and mucosal infections and refractory autoimmune cytopenias. Patients exhibited CD4+ T-cell lymphopenia, decreased T-cell proliferation, cell cycle progression, and increased T-cell apoptosis in response to mitogens. In vitro T-cell differentiation of CD34+ cells and molecular signatures of rearrangements at the T-cell receptor α (TRA) locus were indicative of impaired thymocyte survival. These patients also manifested neutropenia and B-cell and natural killer (NK)-cell lymphopenia. Lentivirus-mediated transfer of the SASH3 complementary DNA-corrected protein expression, in vitro proliferation, and signaling in SASH3-deficient Jurkat and patient-derived T cells. These findings define a new type of X-linked combined immunodeficiency in humans that recapitulates many of the abnormalities reported in mice with Sly1-/- and Sly1Δ/Δ mutations, highlighting an important role of SASH3 in human lymphocyte function and survival.

Phase I Study of Zotiraciclib in Combination with Temozolomide for Patients with Recurrent High-grade Astrocytomas.

PURPOSE: To investigate the toxicity profile and establish an optimal dosing schedule of zotiraciclib with temozolomide in patients with recurrent high-grade astrocytoma. PATIENTS AND METHODS: This two-stage phase I trial determined the MTD of zotiraciclib combined with either dose-dense (Arm1) or metronomic (Arm2) temozolomide using a Bayesian Optimal Interval design; then a randomized cohort expansion compared the progression-free survival rate at 4 months (PFS4) of the two arms for an efficient determination of a temozolomide schedule to combine with zotiraciclib at MTD. Pharmacokinetic and pharmacogenomic profiling were included. Patient-reported outcome was evaluated by longitudinal symptom burden. RESULTS: Fifty-three patients were enrolled. Dose-limiting toxicities were neutropenia, diarrhea, elevated liver enzymes, and fatigue. MTD of zotiraciclib was 250 mg in both arms and thus selected for the cohort expansion. Dose-dense temozolomide plus zotiraciclib (PSF4 40%) compared favorably with metronomic temozolomide (PFS4 25%). Symptom burden worsened at cycle 2 but stabilized by cycle 4 in both arms. A significant decrease in absolute neutrophil count and neutrophil reactive oxygen species production occurred 12-24 hours after an oral dose of zotiraciclib but both recovered by 72 hours. Pharmacokinetic/pharmacogenomic analyses revealed that the CYP1A2_5347T>C (rs2470890) polymorphism was associated with higher AUCinf value. CONCLUSIONS: Zotiraciclib combined with temozolomide is safe in patients with recurrent high-grade astrocytomas. Zotiraciclib-induced neutropenia can be profound but mostly transient, warranting close monitoring rather than treatment discontinuation. Once validated, polymorphisms predicting drug metabolism may allow personalized dosing of zotiraciclib.

Time-resolved systems immunology reveals a late juncture linked to fatal COVID-19.

COVID-19 exhibits extensive patient-to-patient heterogeneity. To link immune response variation to disease severity and outcome over time, we longitudinally assessed circulating proteins as well as 188 surface protein markers, transcriptome, and T cell receptor sequence simultaneously in single peripheral immune cells from COVID-19 patients. Conditional-independence network analysis revealed primary correlates of disease severity, including gene expression signatures of apoptosis in plasmacytoid dendritic cells and attenuated inflammation but increased fatty acid metabolism in CD56dimCD16hi NK cells linked positively to circulating interleukin (IL)-15. CD8+ T cell activation was apparent without signs of exhaustion. Although cellular inflammation was depressed in severe patients early after hospitalization, it became elevated by days 17-23 post symptom onset, suggestive of a late wave of inflammatory responses. Furthermore, circulating protein trajectories at this time were divergent between and predictive of recovery versus fatal outcomes. Our findings stress the importance of timing in the analysis, clinical monitoring, and therapeutic intervention of COVID-19.

Enhanced homology-directed repair for highly efficient gene editing in hematopoietic stem/progenitor cells.

Lentivector gene therapy for X-linked chronic granulomatous disease (X-CGD) has proven to be a viable approach, but random vector integration and subnormal protein production from exogenous promoters in transduced cells remain concerning for long-term safety and efficacy. A previous genome editing-based approach using Streptococcus pyogenes Cas9 mRNA and an oligodeoxynucleotide donor to repair genetic mutations showed the capability to restore physiological protein expression but lacked sufficient efficiency in quiescent CD34+ hematopoietic cells for clinical translation. Here, we report that transient inhibition of p53-binding protein 1 (53BP1) significantly increased (2.3-fold) long-term homology-directed repair to achieve highly efficient (80% gp91phox+ cells compared with healthy donor control subjects) long-term correction of X-CGD CD34+ cells.

Low Plasma Gelsolin Concentrations in Chronic Granulomatous Disease.

Plasma gelsolin (pGSN) is the secreted isoform of an intracellular actin remodeling protein found in high concentrations in human plasma. Clinical studies demonstrate reduced pGSN concentrations in several disease states, including severe trauma, burns, and sepsis. Markedly decreased pGSN concentrations in these conditions precede and predict adverse clinical outcomes. In this study, we measured pGSN in patients with chronic granulomatous disease (CGD), a primary immunodeficiency characterized by recurrent infections and dysregulated inflammation. pGSN was quantified using a sandwich ELISA in plasma from healthy volunteers, clinically stable CGD patients, and X-linked CGD carriers and in sera from 12 CGD patients undergoing bone marrow transplantation. pGSN was also quantified in healthy volunteers challenged with intravenous endotoxin. pGSN concentrations were lower in CGD patients without active infection or systemic inflammation compared with healthy control subjects. In CGD patients undergoing bone marrow transplantation, pGSN concentrations increased significantly following successful transplant. X-linked carriers of CGD had normal pGSN. Despite reduction of pGSN in CGD patients, we did not detect significant changes in pGSN over 24 h following challenge of healthy volunteers with intravenous endotoxin (4 ng/kg) that elicited a febrile response. We describe, for the first time, significantly lower pGSN in clinically stable patients with CGD compared with age- and sex-matched healthy volunteers. Low pGSN levels in CGD patients significantly increased following bone marrow transplantation. X-linked carriers of CGD had normal pGSN. In healthy volunteers challenged with intravenous endotoxin, pGSN is not an acute phase reactant.