IgG4-related disease and B-cell malignancy due to an IKZF1 gain-of-function variant.

BACKGROUND: Monoallelic loss-of-function IKZF1 (IKAROS) variants cause B-cell deficiency or combined immunodeficiency, whereas monoallelic gain-of-function (GOF) IKZF1 variants have recently been reported to cause hypergammaglobulinemia, abnormal plasma cell differentiation, autoimmune and allergic manifestations, and infections. OBJECTIVE: We studied 7 relatives with autoimmune/inflammatory and lymphoproliferative manifestations to identify the immunologic disturbances and the genetic cause of their disease. METHODS: We analyzed biopsy results and performed whole-exome sequencing and immunologic studies. RESULTS: Disease onset occurred at a mean age of 25.2 years (range, 10-64, years). Six patients suffered from autoimmune/inflammatory diseases, 4 had confirmed IG4-related disease (IgG4-RD), and 5 developed B-cell malignancies: lymphoma in 4 and multiple myeloma in the remaining patient. Patients without immunosuppression were not particularly prone to infectious diseases. Three patients suffered from life-threatening coronavirus disease 2019 pneumonia, of whom 1 had autoantibodies neutralizing IFN-α. The recently described IKZF1 GOF p.R183H variant was found in the 5 affected relatives tested and in a 6-year-old asymptomatic girl. Immunologic analysis revealed hypergammaglobulinemia and high frequencies of certain lymphocyte subsets (exhausted B cells, effector memory CD4 T cells, effector memory CD4 T cells that have regained surface expression of CD45RA and CD28-CD57+ CD4+ and CD8+ T cells, TH2, and Tfh2 cells) attesting to immune dysregulation. Partial clinical responses to rituximab and corticosteroids were observed, and treatment with lenalidomide, which promotes IKAROS degradation, was initiated in 3 patients. CONCLUSIONS: Heterozygosity for GOF IKZF1 variants underlies autoimmunity/inflammatory diseases, IgG4-RD, and B-cell malignancies, the onset of which may occur in adulthood. Clinical and immunologic data are similar to those for patients with unexplained IgG4-RD. Patients may therefore benefit from treatments inhibiting pathways displaying IKAROS-mediated overactivity.

Inherited Human BCL10 Deficiencies.

Human BCL10 deficiency causes combined immunodeficiency with bone marrow transplantation as its only curative option. To date, there are four homozygous mutations described in the literature that were identified in four unrelated patients. Here, we describe a fifth patient with a novel mutation and summarize what we have learned about BCL10 deficiency. Due to the severity of the disease, accurate knowledge of its clinical and immunological characteristics is instrumental for early diagnosis and adequate clinical management of the patients.

Inherited human ezrin deficiency impairs adaptive immunity.

BACKGROUND: Inborn errors of immunity (IEI) are a group of monogenic diseases that confer susceptibility to infection, autoimmunity, and cancer. Despite the life-threatening consequences of some IEI, their genetic cause remains unknown in many patients. OBJECTIVE: We investigated a patient with an IEI of unknown genetic etiology. METHODS: Whole-exome sequencing identified a homozygous missense mutation of the gene encoding ezrin (EZR), substituting a threonine for an alanine at position 129. RESULTS: Ezrin is one of the subunits of the ezrin, radixin, and moesin (ERM) complex. The ERM complex links the plasma membrane to the cytoskeleton and is crucial for the assembly of an efficient immune response. The A129T mutation abolishes basal phosphorylation and decreases calcium signaling, leading to complete loss of function. Consistent with the pleiotropic function of ezrin in myriad immune cells, multidimensional immunophenotyping by mass and flow cytometry revealed that in addition to hypogammaglobulinemia, the patient had low frequencies of switched memory B cells, CD4+ and CD8+ T cells, MAIT, γδ T cells, and centralnaive CD4+ cells. CONCLUSIONS: Autosomal-recessive human ezrin deficiency is a newly recognized genetic cause of B-cell deficiency affecting cellular and humoral immunity.

Humans with inherited MyD88 and IRAK-4 deficiencies are predisposed to hypoxemic COVID-19 pneumonia.

X-linked recessive deficiency of TLR7, a MyD88- and IRAK-4-dependent endosomal ssRNA sensor, impairs SARS-CoV-2 recognition and type I IFN production in plasmacytoid dendritic cells (pDCs), thereby underlying hypoxemic COVID-19 pneumonia with high penetrance. We report 22 unvaccinated patients with autosomal recessive MyD88 or IRAK-4 deficiency infected with SARS-CoV-2 (mean age: 10.9 yr; 2 mo to 24 yr), originating from 17 kindreds from eight countries on three continents. 16 patients were hospitalized: six with moderate, four with severe, and six with critical pneumonia, one of whom died. The risk of hypoxemic pneumonia increased with age. The risk of invasive mechanical ventilation was also much greater than in age-matched controls from the general population (OR: 74.7, 95% CI: 26.8-207.8, P < 0.001). The patients' susceptibility to SARS-CoV-2 can be attributed to impaired TLR7-dependent type I IFN production by pDCs, which do not sense SARS-CoV-2 correctly. Patients with inherited MyD88 or IRAK-4 deficiency were long thought to be selectively vulnerable to pyogenic bacteria, but also have a high risk of hypoxemic COVID-19 pneumonia.

Case Report: Novel STIM1 Gain-of-Function Mutation in a Patient With TAM/STRMK and Immunological Involvement.

Gain-of-function (GOF) mutations in STIM1 are responsible for tubular aggregate myopathy and Stormorken syndrome (TAM/STRMK), a clinically overlapping multisystemic disease characterised by muscle weakness, miosis, thrombocytopaenia, hyposplenism, ichthyosis, dyslexia, and short stature. Several mutations have been reported as responsible for the disease. Herein, we describe a patient with TAM/STRMK due to a novel L303P STIM1 mutation, who not only presented clinical manifestations characteristic of TAM/STRMK but also manifested immunological involvement with respiratory infections since childhood, with chronic cough and chronic bronchiectasis. Despite the seemingly normal main immunological parameters, immune cells revealed GOF in calcium signalling compared with healthy donors. The calcium flux dysregulation in the immune cells could be responsible for our patient's immune involvement. The patient's mother carried the mutation but did not exhibit TAM/STRMK, manifesting an incomplete penetrance of the mutation. More cases and evidence are necessary to clarify the dual role of STIM1 in immune system dysregulation and myopathy.

Ruxolitinib does not completely abrogate the functional capabilities of TLR4/9 ligand-activated NK cells.

Introduction: Natural killer (NK) cells are lymphocytes from the innate immune system part of the first defense barrier against infected and transformed cells, representing 5%-15% of peripheral blood lymphocytes. The cytotoxic capacity of NK cells is controlled by a balance between inhibitory and activating NK receptors expressed on their surface, which recognize and interact with the ligands on stressed cells. The cytokines involved in NK cell activation, proliferation, survival, and cytotoxicity are signaled mainly through the Janus kinase and signal transducer and activator of transcription proteins (JAK/STAT) pathway. NK cells are also activated in response to pathogens through Toll-like receptors (TLRs) expressed on their surface. Ruxolitinib is a specific JAK1/2 inhibitor approved for treating myelofibrosis and for steroid-refractory acute and chronic graft-versus-host disease (SR-GvHD). Methods: Purified NK cells from healthy donors were stimulated with two TOLL-like receptor ligands, LPS and CpG, in the presence of different concentrations of Ruxolitinib. Results: This study showed the effects of ruxolitinib on TLR4 and TLR9 ligand-activated NK cells from healthy donors. Ruxolitinib did not completely inhibit STAT3 phosphorylation and had a moderate effect on NK cell cytokine activation via the TLR pathway. Only the highest doses of ruxolitinib led to a decrease in the pro-inflammatory cytokines tumor necrosis factor α, interferon-γ, interleukin-6, and interleukin-1ß. The cytotoxic capacity of stimulated NK cells versus K562, SEM, and MV-4-11 cell lines was reduced by increasing doses of ruxolitinib, but it was not completely abolished and we observed no major changes in degranulation capacity. Phenotypic changes were observed in activated NK cells in the presence of ruxolitinib. In a small cohort of pediatric patients treated with ruxolitinib for SR-GvHD, we observed no decrease in NK cell counts; however, further prospective studies with larger cohorts are necessary to confirm this finding. Discussion: In summary, our results showed that the functional capabilities and phenotype of NK cells activated through TLR4/9 agonists were not completely abolished by the inhibition of the JAK-STAT pathway by ruxolitinib.

Clinical and Immunological Features of Human BCL10 Deficiency.

The CARD-BCL10-MALT1 (CBM) complex is critical for the proper assembly of human immune responses. The clinical and immunological consequences of deficiencies in some of its components such as CARD9, CARD11, and MALT1 have been elucidated in detail. However, the scarcity of BCL10 deficient patients has prevented gaining detailed knowledge about this genetic disease. Only two patients with BCL10 deficiency have been reported to date. Here we provide an in-depth description of an additional patient with autosomal recessive complete BCL10 deficiency caused by a nonsense mutation that leads to a loss of expression (K63X). Using mass cytometry coupled with unsupervised clustering and machine learning computational methods, we obtained a thorough characterization of the consequences of BCL10 deficiency in different populations of leukocytes. We showed that in addition to the near absence of memory B and T cells previously reported, this patient displays a reduction in NK, γδT, Tregs, and TFH cells. The patient had recurrent respiratory infections since early childhood, and showed a family history of lethal severe infectious diseases. Fortunately, hematopoietic stem-cell transplantation (HSCT) cured her. Overall, this report highlights the importance of early genetic diagnosis for the management of BCL10 deficient patients and HSCT as the recommended treatment to cure this disease.

Neurofibromin 1 in mushroom body neurons mediates circadian wake drive through activating cAMP-PKA signaling.

Various behavioral and cognitive states exhibit circadian variations in animals across phyla including Drosophila melanogaster, in which only ~0.1% of the brain's neurons contain circadian clocks. Clock neurons transmit the timing information to a plethora of non-clock neurons via poorly understood mechanisms. Here, we address the molecular underpinning of this phenomenon by profiling circadian gene expression in non-clock neurons that constitute the mushroom body, the center of associative learning and sleep regulation. We show that circadian clocks drive rhythmic expression of hundreds of genes in mushroom body neurons, including the Neurofibromin 1 (Nf1) tumor suppressor gene and Pka-C1. Circadian clocks also drive calcium rhythms in mushroom body neurons via NF1-cAMP/PKA-C1 signaling, eliciting higher mushroom body activity during the day than at night, thereby promoting daytime wakefulness. These findings reveal the pervasive, non-cell-autonomous circadian regulation of gene expression in the brain and its role in sleep.

Novel PGM3 compound heterozygous variants with IgE-related dermatitis, lymphopenia, without syndromic features.

BACKGROUND: Phosphoglucomutase-3 (PGM3) deficiency is a congenital disorder of glycosylation (CDG) with hyperimmunoglobulin IgE, atopy, and a variable immunological phenotype; most reported patients display dysmorphic features. The aim of the study was to characterize the genotype and phenotype of individuals with newly identified compound heterozygous variants in the phosphate-binding domain of PGM3 in order to better understand phenotypic differences between these patients and published cases. METHODS: We analyzed PGM3 protein expression, PGM3 enzymatic activity, the presence of other gene variants within the N-glycosylation pathway, and the clinical and immunological manifestations of two affected siblings. RESULTS: Patients belonged to a non-consanguineous family, presenting with atopic dermatitis, elevated levels of IgE, and CD4+ lymphopenia (a more severe phenotype was observed in Patient 2), but lacked dysmorphic features or neurocognitive impairment. Compound heterozygous PGM3 variants were identified, located in the phosphate-binding domain of the enzyme. PGM3 expression was comparable to healthy donors, but L-PHA binding in naïve-CD4+ cells was decreased. Examination of exome sequence identified the presence of one additional candidate variant of unknown significance (VUS) in the N-glycosylation pathway in Patient 2: a variant predicted to have moderate-to-high impact in ALG12. CONCLUSIONS: Our analysis revealed that L-PHA binding is reduced in naïve-CD4+ cells, which is consistent with decreased residual PGM3 enzymatic activity. Other gene variants in the N-glycosylation pathway may modify patient phenotypes in PGM3 deficiency. This study expands the clinical criteria for when PGM3 deficiency should be considered among individuals with hyper-IgE.

Daño al ADN en mujeres expuestas al humo de la leña en Chiapas, México / DNA damage in women exposed to firewood fuel smoke in Chiapas, Mexico

Actualmente alrededor de la cuarta parte de la población mexicana, entre 25 y 28 millones de habitantes, cocina con leña. Sin embargo, el humo de la leña contiene una amplia gama de sustancias tóxicas, entre ellas el monóxido de carbono (CO) cuyo impacto en la salud de la población rural debe ser estudiado. Por esto, el potencial daño al ADN asociado con la exposición a CO de 30 mujeres que cocinaban con leña en Chiapas, México, fue evaluado por el ensayo cometa. Los resultados se compararon con 30 controles comparables en edad y condiciones socioeconómicas, quienes cocinaban con gas licuado de petróleo (GLP). Se obtuvieron muestras de sangre total para medir carboxihemoglobina (COHb) y llevar a cabo el ensayo cometa. Se encontró diferencia significativa (P<0,001) en las concentraciones de COHb entre las mujeres que cocinaban con leña (media= 6,6%) y las que lo hacían con GLP (media= 1,8%), siendo 3,6 veces más elevadas en las primeras antes citadas que en las segundas. Se encontraron diferencias significativas en la longitud de cola (media ± DE = 18,5 +/- 4,21 contra 5,97 +/- 1,0 μm, P<0,001) y en el momento de cola (media ± DE = 4,55 +/- 1,5 contra 1,5 +/- 0,40, P<0,001) del cometa entre los dos grupos examinados. Los resultados del presente estudio sugieren fuertemente que la exposición a CO y componentes presentes en el humo de la leña, puede causar daño genotóxico a las mujeres que hacen uso de este combustible, por lo que es necesario implementar medidas que disminuyan esta exposición.

Currently, about a quarter of the Mexican population, between 25 and 28 million people, cook with firewood. However, wood smoke contains a wide range of toxic substances, including carbon monoxide (CO) whose impact on health of the rural population should be studied. Therefore, the potential DNA damage associated with the exposition to CO of 30 women who cooked with wood in Chiapas, Mexico, was assessed using Comet Assay. Results were compared with 30 controls of similarage and socioeconomic status, who cooked with liquefied petroleum gas (LPG). We obtained whole blood samples to measure carboxyhemoglobin (% COHb) and perform the comet assay. There was a significant difference (P <0.001) in the percentages of COHb between women who cooked with wood (mean= 6.6%) and those who did it with LPG (mean=1.8%) being 3.6 times higher in the former compared with the latter. There was a significant difference in comet tail length between the two groups examined (mean 18.5 +/- 4.21 versus 5.97 +/- 1.0 μm, P <0.001) and tail moment (mean 4.55 +/- 1.5 versus 1.5 +/- 0.40, P <0.001). The results of this study strongly suggest that exposure to carbon monoxide and compounds present in wood smoke can cause genotoxic damage to women who use this fuel, so it is necessary to implement measures to reduce this exposure.

Daño al ADN en mujeres expuestas al humo de la leña en Chiapas, México / DNA damage in women exposed to firewood fuel smoke in Chiapas, Mexico

Actualmente alrededor de la cuarta parte de la población mexicana, entre 25 y 28 millones de habitantes, cocina con leña. Sin embargo, el humo de la leña contiene una amplia gama de sustancias tóxicas, entre ellas el monóxido de carbono (CO) cuyo impacto en la salud de la población rural debe ser estudiado. Por esto, el potencial daño al ADN asociado con la exposición a CO de 30 mujeres que cocinaban con leña en Chiapas, México, fue evaluado por el ensayo cometa. Los resultados se compararon con 30 controles comparables en edad y condiciones socioeconómicas, quienes cocinaban con gas licuado de petróleo (GLP). Se obtuvieron muestras de sangre total para medir carboxihemoglobina (COHb) y llevar a cabo el ensayo cometa. Se encontró diferencia significativa (P<0,001) en las concentraciones de COHb entre las mujeres que cocinaban con leña (media= 6,6%) y las que lo hacían con GLP (media= 1,8%), siendo 3,6 veces más elevadas en las primeras antes citadas que en las segundas. Se encontraron diferencias significativas en la longitud de cola (media ± DE = 18,5 +/- 4,21 contra 5,97 +/- 1,0 μm, P<0,001) y en el momento de cola (media ± DE = 4,55 +/- 1,5 contra 1,5 +/- 0,40, P<0,001) del cometa entre los dos grupos examinados. Los resultados del presente estudio sugieren fuertemente que la exposición a CO y componentes presentes en el humo de la leña, puede causar daño genotóxico a las mujeres que hacen uso de este combustible, por lo que es necesario implementar medidas que disminuyan esta exposición.(AU)

Currently, about a quarter of the Mexican population, between 25 and 28 million people, cook with firewood. However, wood smoke contains a wide range of toxic substances, including carbon monoxide (CO) whose impact on health of the rural population should be studied. Therefore, the potential DNA damage associated with the exposition to CO of 30 women who cooked with wood in Chiapas, Mexico, was assessed using Comet Assay. Results were compared with 30 controls of similarage and socioeconomic status, who cooked with liquefied petroleum gas (LPG). We obtained whole blood samples to measure carboxyhemoglobin (% COHb) and perform the comet assay. There was a significant difference (P <0.001) in the percentages of COHb between women who cooked with wood (mean= 6.6%) and those who did it with LPG (mean=1.8%) being 3.6 times higher in the former compared with the latter. There was a significant difference in comet tail length between the two groups examined (mean 18.5 +/- 4.21 versus 5.97 +/- 1.0 μm, P <0.001) and tail moment (mean 4.55 +/- 1.5 versus 1.5 +/- 0.40, P <0.001). The results of this study strongly suggest that exposure to carbon monoxide and compounds present in wood smoke can cause genotoxic damage to women who use this fuel, so it is necessary to implement measures to reduce this exposure.(AU)

An enhanced obstetrics track for a family practice residency program: results from the first 6 years.

BACKGROUND: Advanced training in obstetrics for family physicians occurs through a variety of methods. The program described has developed an obstetrics track for family practice residents. METHODS: Five residents have completed the 4-year residency program with enhanced obstetric training developed, and the results, in terms of procedural experience and examination scores, have been reviewed. RESULTS: These 5 family physicians performed a similar number of obstetric procedures compared with their Obstetrics and Gynecology resident counterparts, and they performed as well as their family medicine resident counterparts on national in-service examinations. CONCLUSIONS: A 4-year enhanced obstetrics track is an effective means of improving the training of family medicine residents in obstetric procedures while maintaining the other fundamental training and residency review committee requirements for family medicine residents.