A randomized, placebo-controlled phase 3 trial of the PI3Kδ inhibitor leniolisib for activated PI3Kδ syndrome.

Activated phosphoinositide 3-kinase delta (PI3Kδ) syndrome (APDS) is an inborn error of immunity with clinical manifestations including infections, lymphoproliferation, autoimmunity, enteropathy, bronchiectasis, increased risk of lymphoma, and early mortality. Hyperactive PI3Kδ signaling causes APDS and is selectively targeted with leniolisib, an oral, small molecule inhibitor of PI3Kδ. Here, 31 patients with APDS aged ≥12 years were enrolled in a global, phase 3, triple-blinded trial and randomized 2:1 to receive 70 mg leniolisib or placebo twice daily for 12 weeks. Coprimary outcomes were differences from baseline in the index lymph node size and the percentage of naïve B cells in peripheral blood, assessed as proxies for immune dysregulation and deficiency. Both primary outcomes were met: the difference in the adjusted mean change (95% confidence interval [CI]) between leniolisib and placebo for lymph node size was -0.25 (-0.38, -0.12; P = .0006; N = 26) and for percentage of naïve B cells, was 37.30 (24.06, 50.54; P = .0002; N = 13). Leniolisib reduced spleen volume compared with placebo (adjusted mean difference in 3-dimensional volume [cm3], -186; 95% CI, -297 to -76.2; P = .0020) and improved key immune cell subsets. Fewer patients receiving leniolisib reported study treatment-related adverse events (AEs; mostly grades 1-2) than those receiving placebo (23.8% vs 30.0%). Overall, leniolisib was well tolerated and significant improvement over placebo was notable in the coprimary endpoints, reducing lymphadenopathy and increasing the percentage of naïve B cells, reflecting a favorable impact on the immune dysregulation and deficiency seen in patients with APDS. This trial was registered at www.clinicaltrials.gov as #NCT02435173.

Interim analysis: Open-label extension study of leniolisib for patients with APDS.

BACKGROUND: Activated phosphoinositide 3-kinase delta (PI3Kδ) syndrome (APDS; or p110δ-activating mutations causing senescent T cells, lymphadenopathy, and immunodeficiency) is an inborn error of immunity caused by PI3Kδ hyperactivity. Resultant immune deficiency and dysregulation lead to recurrent sinopulmonary infections, herpes viremia, autoimmunity, and lymphoproliferation. OBJECTIVE: Leniolisib, a selective PI3Kδ inhibitor, demonstrated favorable impact on immune cell subsets and lymphoproliferation over placebo in patients with APDS over 12 weeks. Here, we report results from an interim analysis of an ongoing open-label, single-arm extension study. METHODS: Patients with APDS aged 12 years or older who completed NCT02435173 or had previous exposure to PI3Kδ inhibitors were eligible. The primary end point was safety, assessed via investigator-reported adverse events (AEs) and clinical/laboratory evaluations. Secondary and exploratory end points included health-related quality of life, inflammatory markers, frequency of infections, and lymphoproliferation. RESULTS: Between September 2016 and August 2021, 37 patients (median age, 20 years; 42.3% female) were enrolled. Of these 37 patients, 26, 9, and 2 patients had previously received leniolisib, placebo, or other PI3Kδ inhibitors, respectively. At the data cutoff date (December 13, 2021), median leniolisib exposure was 102 weeks. Overall, 32 patients (87%) experienced an AE. Most AEs were grades 1 to 3; none were grade 4. One patient with severe baseline comorbidities experienced a grade 5 AE, determined as unrelated to leniolisib treatment. While on leniolisib, patients had reduced annualized infection rates (P = .004), and reductions in immunoglobulin replacement therapy occurred in 10 of 27 patients. Other observations include reduced lymphadenopathy and splenomegaly, improved cytopenias, and normalized lymphocyte subsets. CONCLUSIONS: Leniolisib was well tolerated and maintained durable outcomes with up to 5 years of exposure in 37 patients with APDS. CLINICALTRIALS: gov identifier: NCT02859727.

DOCK8 functions as an adaptor that links TLR-MyD88 signaling to B cell activation.

The adaptors DOCK8 and MyD88 have been linked to serological memory. Here we report that DOCK8-deficient patients had impaired antibody responses and considerably fewer CD27(+) memory B cells. B cell proliferation and immunoglobulin production driven by Toll-like receptor 9 (TLR9) were considerably lower in DOCK8-deficient B cells, but those driven by the costimulatory molecule CD40 were not. In contrast, TLR9-driven expression of AICDA (which encodes the cytidine deaminase AID), the immunoglobulin receptor CD23 and the costimulatory molecule CD86 and activation of the transcription factor NF-κB, the kinase p38 and the GTPase Rac1 were intact. DOCK8 associated constitutively with MyD88 and the tyrosine kinase Pyk2 in normal B cells. After ligation of TLR9, DOCK8 became tyrosine-phosphorylated by Pyk2, bound the Src-family kinase Lyn and linked TLR9 to a Src-kinase Syk-transcription factor STAT3 cascade essential for TLR9-driven B cell proliferation and differentiation. Thus, DOCK8 functions as an adaptor in a TLR9-MyD88 signaling pathway in B cells.

CVID-Associated B Cell Activating Factor Receptor Variants Change Receptor Oligomerization, Ligand Binding, and Signaling Responses.

PURPOSE: Binding of the B cell activating factor (BAFF) to its receptor (BAFFR) activates in mature B cells many essential pro-survival functions. Null mutations in the BAFFR gene result in complete BAFFR deficiency and cause a block in B cell development at the transition from immature to mature B cells leading therefore to B lymphopenia and hypogammaglobulinemia. In addition to complete BAFFR deficiency, single nucleotide variants encoding BAFFR missense mutations were found in patients suffering from common variable immunodeficiency (CVID), autoimmunity, or B cell lymphomas. As it remained unclear to which extent such variants disturb the activity of BAFFR, we performed genetic association studies and developed a cellular system that allows the unbiased analysis of BAFFR variants regarding oligomerization, signaling, and ectodomain shedding. METHODS: In addition to genetic association studies, the BAFFR variants P21R, A52T, G64V, DUP92-95, P146S, and H159Y were expressed by lentiviral gene transfer in DG-75 Burkitt's lymphoma cells and analyzed for their impacts on BAFFR function. RESULTS: Binding of BAFF to BAFFR was affected by P21R and A52T. Spontaneous oligomerization of BAFFR was disturbed by P21R, A52T, G64V, and P146S. BAFF-dependent activation of NF-κB2 was reduced by P21R and P146S, while interactions between BAFFR and the B cell antigen receptor component CD79B and AKT phosphorylation were impaired by P21R, A52T, G64V, and DUP92-95. P21R, G64V, and DUP92-95 interfered with phosphorylation of ERK1/2, while BAFF-induced shedding of the BAFFR ectodomain was only impaired by P21R. CONCLUSION: Although all variants change BAFFR function and have the potential to contribute as modifiers to the development of primary antibody deficiencies, autoimmunity, and lymphoma, P21R is the only variant that was found to correlate positively with CVID.

Follicular helper T cell signature of replicative exhaustion, apoptosis, and senescence in common variable immunodeficiency.

Common variable immunodeficiency (CVID) is the most frequent primary antibody deficiency whereby follicular helper T (Tfh) cells fail to establish productive responses with B cells in germinal centers. Here, we analyzed the frequency, phenotype, transcriptome, and function of circulating Tfh (cTfh) cells in CVID patients displaying autoimmunity as an additional phenotype. A group of patients showed a high frequency of cTfh1 cells and a prominent expression of PD-1 and ICOS as well as a cTfh mRNA signature consistent with highly activated, but exhausted, senescent, and apoptotic cells. Plasmatic CXCL13 levels were elevated in this group and positively correlated with cTfh1 cell frequency and PD-1 levels. Monoallelic variants in RTEL1, a telomere length- and DNA repair-related gene, were identified in four patients belonging to this group. Their blood lymphocytes showed shortened telomeres, while their cTfh were more prone to apoptosis. These data point toward a novel pathogenetic mechanism in CVID, whereby alterations in DNA repair and telomere elongation might predispose to antibody deficiency. A Th1, highly activated but exhausted and apoptotic cTfh phenotype was associated with this form of CVID.

B cell-helper neutrophils stimulate the diversification and production of immunoglobulin in the marginal zone of the spleen.

Neutrophils use immunoglobulins to clear antigen, but their role in immunoglobulin production is unknown. Here we identified neutrophils around the marginal zone (MZ) of the spleen, a B cell area specialized in T cell-independent immunoglobulin responses to circulating antigen. Neutrophils colonized peri-MZ areas after postnatal mucosal colonization by microbes and enhanced their B cell-helper function after receiving reprogramming signals, including interleukin 10 (IL-10), from splenic sinusoidal endothelial cells. Splenic neutrophils induced immunoglobulin class switching, somatic hypermutation and antibody production by activating MZ B cells through a mechanism that involved the cytokines BAFF, APRIL and IL-21. Neutropenic patients had fewer and hypomutated MZ B cells and a lower abundance of preimmune immunoglobulins to T cell-independent antigens, which indicates that neutrophils generate an innate layer of antimicrobial immunoglobulin defense by interacting with MZ B cells.

Clinical and transcriptomic characteristics of a novel SMARCD2 mutation that disrupts neutrophil maturation and function.

We report a novel case of SMARCD2 (SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin, subfamily D, member 2) mutation successfully treated with hematopoietic stem cell transplantation. The female patient presented delayed cord separation, chronic diarrhea, skin abscesses, skeletal dysmorphisms, and neutropenia with specific granule deficiency. Analysis of the transcriptomic profile of peripheral blood sorted mature and immature SMARCD2 neutrophils showed defective maturation process that associated with altered expression of genes related to specific, azurophilic, and gelatinase granules, such as LTF, CRISP3, PTX3, and CHI3L1. These abnormalities account for the prevalence of immature neutrophils in the peripheral blood, impaired function, and deregulated inflammatory responses.

Lack of DOCK8 impairs the primary biologic functions of human NK cells and abrogates CCR7 surface expression in a WASP-independent manner.

Dedicator of Cytokinesis 8 (DOCK8) deficiency is a rare form of autosomal recessive combined immunodeficiency. The effect of DOCK8 deficiency on Natural Killer cell biology has not been fully elucidated yet. Thus, we undertook a detailed phenotypic and functional evaluation of NK cells from seven patients with DOCK8 deficiency. Patients' immature CD56bright NK cells were defective in IFN-γ secretion, while their mature CD56dim NK cells showed impaired cytotoxicity, partially rescued upon rIL-2 addition. Cross-linking of NK cell receptors revealed a specific defect in the CD3 zeta chain-dependent activation pathway in DOCK8 deficiency. Lack of DOCK8, but not of WASP, impaired CCR7 expression on human CD56bright NK cells, a critical receptor for their migration to secondary lymph nodes. Evaluation of a patient's lymph node showed a severe reduction in NK cells that showed increased intracellular expression of CCR7. Our data suggest that DOCK8 deficiency variably affects NK cell homeostasis in humans.

Lymphocyte alterations in patients with Common Variable Immunodeficiency (CVID) and autoimmune manifestations.

INTRODUCTION: Autoimmunity is a common feature in CVID patients. To date the mechanisms leading to the development of such complications are not fully elucidated. MATERIALS AND METHODS: Data from 122 CVID patients subdivided in three groups based on the absence of autoimmunity (n-AI) or the presence of hematologic autoimmune phenomena (Cy-AI) or non-hematologic autoimmune phenomena (n-Cy-AI) were evaluated. RESULTS: We identified a total of 128 autoimmune manifestations in 55/122 patients (45.1%). 30/122 (24.6%) patients presented hematologic autoimmune phenomena while 29/122 (23.8%) presented gastrointestinal autoimmune involvement. Immune thrombocytopenia was the most common manifestation (27/122; 22.1%), followed by autoimmune hemolytic anemia (18/122; 14.8%) and autoimmune enteropathy (17/122; 13.9%). Cy-AI patients displayed higher CD4+ effector memory and terminally differentiated CD8+ cells with lower percentages of naïve and recent thymic emigrants (RTEs) CD4+ cells and a significant expansion of the CD19hiCD21low population. CONCLUSIONS: CVID patients developing autoimmune cytopenias display characteristic immune phenotypic features.

Immunological Evaluation of Patients Affected with Jacobsen Syndrome Reveals Profound Not Age-Related Lymphocyte Alterations.

PURPOSE: Jacobsen syndrome (JS) is a rare form of genetic disorder that was recently classified as a syndromic immunodeficiency. Available detailed immunological data from JS patients are limited. METHODS: Clinical and immunological presentation of twelve pediatric patients with JS by means of revision of clinical records, flow cytometry, real-time PCR, and lymphocyte functional testing were collected. RESULTS: Recurrent infections were registered in 6/12 patients (50%), while bleeding episodes in 2/12 (16.7%). White blood cell and absolute lymphocyte counts were reduced in 8/12 (66.7%) and 7/12 (58.3%) patients, respectively. Absolute numbers of CD3+ and CD4+ T cells were reduced in 8/12 (66.7%) and 7/12 (58.3%), respectively. Of note, recent thymic emigrants (RTE) were reduced in all tested patients (9/9), with T-cell receptor excision circle analysis (TRECs) showing a similar trend in 8/9 patients; naïve CD4+ T cells were low only in 5/11 patients (45.4%). Interestingly, B-cell counts, IgM memory B cells, and IgM serum levels were reduced in 10/12 (83.3%) patients. Natural killer (NK) cell counts were mostly normal but the percentages of CD16+CD56low/- cells were expanded in 7/7 patients tested. The observed immunological alterations did not correlate with patients' age. Finally, responses to proliferative stimuli were normal at presentation for all patients, although they may deteriorate over time. CONCLUSIONS: Our data suggest that patients affected with JS may display important numeric and maturational alterations in the T-, B-, and NK-cell compartments. These findings suggest that JS patients should be regularly monitored from an immunological point of view.

The Impact of SARS-CoV-2 Infection in Patients with Inborn Errors of Immunity: the Experience of the Italian Primary Immunodeficiencies Network (IPINet).

COVID-19 manifestations range from asymptomatic to life-threatening infections. The outcome in different inborn errors of immunity (IEI) is still a matter of debate. In this retrospective study, we describe the experience of the of the Italian Primary Immunodeficiencies Network (IPINet). Sixteen reference centers for adult or pediatric IEI were involved. One hundred fourteen patients were enrolled including 35 pediatric and 79 adult patients. Median age was 32 years, and male-to-female ratio was 1.5:1. The most common IEI were 22q11.2 deletion syndrome in children (26%) and common variable immunodeficiency (CVID) in adults (65%). Ninety-one patients did not require hospital admission, and among these, 33 were asymptomatic. Hospitalization rate was 20.17%. Older age (p 0.004) and chronic lung disease (p 0.0008) represented risk factors for hospitalization. Hospitalized patients mainly included adults suffering from humoral immunodeficiencies requiring immunoglobulin replacement therapy and as expected had lower B cell counts compared to non-hospitalized patients. Infection fatality rate in the whole cohort was 3.5%. Seroconversion was observed is 86.6% of the patients evaluated and in 83.3% of CVID patients. 16.85% of the patients reported long-lasting COVID symptoms. All but one patient with prolonged symptoms were under IgRT. The fatality rate observed in IEI was slightly similar to the general population. The age of the patients who did not survive was lower compared to the general population, and the age stratified mortality in the 50-60 age range considerable exceeded the mortality from 50 to 60 age group of the Italian population (14.3 vs 0.6%; p < 0.0001). We hypothesize that this is due to the fact that comorbidities in IEI patients are very common and usually appear early in life.

Progressive Depletion of B and T Lymphocytes in Patients with Ataxia Telangiectasia: Results of the Italian Primary Immunodeficiency Network.

Ataxia telangiectasia (AT) is a rare neurodegenerative genetic disorder due to bi-allelic mutations in the Ataxia Telangiectasia Mutated (ATM) gene. The aim of this paper is to better define the immunological profile over time, the clinical immune-related manifestations at diagnosis and during follow-up, and to attempt a genotype-phenotype correlation of an Italian cohort of AT patients. Retrospective data of 69 AT patients diagnosed between December 1984 and November 2019 were collected from the database of the Italian Primary Immunodeficiency Network. Patients were classified at diagnosis as lymphopenic (Group A) or non-lymphopenic (Group B). Fifty eight out of 69 AT patients (84%) were genetically characterized and distinguished according to the type of mutations in truncating/truncating (TT; 27 patients), non-truncating (NT)/T (28 patients), and NT/NT (5 patients). In 3 patients, only one mutation was detected. Data on age at onset and at diagnosis, cellular and humoral compartment at diagnosis and follow-up, infectious diseases, signs of immune dysregulation, cancer, and survival were analyzed and compared to the genotype. Lymphopenia at diagnosis was related per se to earlier age at onset. Progressive reduction of cellular compartment occurred during the follow-up with a gradual reduction of T and B cell number. Most patients of Group A carried bi-allelic truncating mutations, had a more severe B cell lymphopenia, and a reduced life expectancy. A trend to higher frequency of interstitial lung disease, immune dysregulation, and malignancy was noted in Group B patients. Lymphopenia at the onset and the T/T genotype are associated with a worst clinical course. Several mechanisms may underlie the premature and progressive immune decline in AT subjects.

The transmembrane activator TACI triggers immunoglobulin class switching by activating B cells through the adaptor MyD88.

BAFF and APRIL are innate immune mediators that trigger immunoglobulin G (IgG) and IgA class-switch recombination (CSR) in B cells by engaging the receptor TACI. The mechanism that underlies CSR signaling by TACI remains unknown. Here we found that the cytoplasmic domain of TACI encompasses a conserved motif that bound MyD88, an adaptor that activates transcription factor NF-kappaB signaling pathways via a Toll-interleukin 1 (IL-1) receptor (TIR) domain. TACI lacks a TIR domain, yet triggered CSR via the DNA-editing enzyme AID by activating NF-kappaB through a Toll-like receptor (TLR)-like MyD88-IRAK1-IRAK4-TRAF6-TAK1 pathway. TACI-induced CSR was impaired in mice and humans lacking MyD88 or the kinase IRAK4, which indicates that MyD88 controls a B cell-intrinsic, TIR-independent, TACI-dependent pathway for immunoglobulin diversification.

Coronavirus disease 2019 in patients with inborn errors of immunity: An international study.

BACKGROUND: There is uncertainty about the impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in individuals with rare inborn errors of immunity (IEI), a population at risk of developing severe coronavirus disease 2019. This is relevant not only for these patients but also for the general population, because studies of IEIs can unveil key requirements for host defense. OBJECTIVE: We sought to describe the presentation, manifestations, and outcome of SARS-CoV-2 infection in IEI to inform physicians and enhance understanding of host defense against SARS-CoV-2. METHODS: An invitation to participate in a retrospective study was distributed globally to scientific, medical, and patient societies involved in the care and advocacy for patients with IEI. RESULTS: We gathered information on 94 patients with IEI with SARS-CoV-2 infection. Their median age was 25 to 34 years. Fifty-three patients (56%) suffered from primary antibody deficiency, 9 (9.6%) had immune dysregulation syndrome, 6 (6.4%) a phagocyte defect, 7 (7.4%) an autoinflammatory disorder, 14 (15%) a combined immunodeficiency, 3 (3%) an innate immune defect, and 2 (2%) bone marrow failure. Ten were asymptomatic, 25 were treated as outpatients, 28 required admission without intensive care or ventilation, 13 required noninvasive ventilation or oxygen administration, 18 were admitted to intensive care units, 12 required invasive ventilation, and 3 required extracorporeal membrane oxygenation. Nine patients (7 adults and 2 children) died. CONCLUSIONS: This study demonstrates that (1) more than 30% of patients with IEI had mild coronavirus disease 2019 (COVID-19) and (2) risk factors predisposing to severe disease/mortality in the general population also seemed to affect patients with IEI, including more younger patients. Further studies will identify pathways that are associated with increased risk of severe disease and are nonredundant or redundant for protection against SARS-CoV-2.

Simple Measurement of IgA Predicts Immunity and Mortality in Ataxia-Telangiectasia.

Patients with ataxia-telangiectasia (A-T) suffer from progressive cerebellar ataxia, immunodeficiency, respiratory failure, and cancer susceptibility. From a clinical point of view, A-T patients with IgA deficiency show more symptoms and may have a poorer prognosis. In this study, we analyzed mortality and immunity data of 659 A-T patients with regard to IgA deficiency collected from the European Society for Immunodeficiencies (ESID) registry and from 66 patients with classical A-T who attended at the Frankfurt Goethe-University between 2012 and 2018. We studied peripheral B- and T-cell subsets and T-cell repertoire of the Frankfurt cohort and survival rates of all A-T patients in the ESID registry. Patients with A-T have significant alterations in their lymphocyte phenotypes. All subsets (CD3, CD4, CD8, CD19, CD4/CD45RA, and CD8/CD45RA) were significantly diminished compared to standard values. Patients with IgA deficiency (n = 35) had significantly lower lymphocyte counts compared to A-T patients without IgA deficiency (n = 31) due to a further decrease of naïve CD4 T-cells, central memory CD4 cells, and regulatory T-cells. Although both patient groups showed affected TCR-ß repertoires compared to controls, no differences could be detected between patients with and without IgA deficiency. Overall survival of patients with IgA deficiency was significantly diminished. For the first time, our data show that patients with IgA deficiency have significantly lower lymphocyte counts and subsets, which are accompanied with reduced survival, compared to A-T patients without IgA deficiency. IgA, a simple surrogate marker, is indicating the poorest prognosis for classical A-T patients. Both non-interventional clinical trials were registered at clinicaltrials.gov 2012 (Susceptibility to infections in ataxia-telangiectasia; NCT02345135) and 2017 (Susceptibility to Infections, tumor risk and liver disease in patients with ataxia-telangiectasia; NCT03357978).

Immunoglobulin D enhances immune surveillance by activating antimicrobial, proinflammatory and B cell-stimulating programs in basophils.

Immunoglobulin D (IgD) is an enigmatic antibody isotype that mature B cells express together with IgM through alternative RNA splicing. Here we report active T cell-dependent and T cell-independent IgM-to-IgD class switching in B cells of the human upper respiratory mucosa. This process required activation-induced cytidine deaminase (AID) and generated local and circulating IgD-producing plasmablasts reactive to respiratory bacteria. Circulating IgD bound to basophils through a calcium-mobilizing receptor that induced antimicrobial, opsonizing, inflammatory and B cell-stimulating factors, including cathelicidin, interleukin 1 (IL-1), IL-4 and B cell-activating factor (BAFF), after IgD crosslinking. By showing dysregulation of IgD class-switched B cells and 'IgD-armed' basophils in autoinflammatory syndromes with periodic fever, our data indicate that IgD orchestrates an ancestral surveillance system at the interface between immunity and inflammation.

Known and potential molecules associated with altered B cell development leading to predominantly antibody deficiencies.

Predominantly antibody deficiencies (PADs) encompass a heterogeneous group of disorders characterized by low immunoglobulin serum levels in the presence or absence of peripheral B cells. Clinical presentation of affected patients may include recurrent respiratory and gastrointestinal infections, invasive infections, autoimmune manifestations, allergic reactions, lymphoproliferation, and increased susceptibility to malignant transformation. In the last decades, several genetic alterations affecting B-cell development/maturation have been identified as causative of several forms of PADs, adding important information on the genetic background of PADs, which in turn should lead to a better understanding of these disorders and precise clinical management of affected patients. This review aimed to present a comprehensive overview of the known and potentially involved molecules in the etiology of PADs to elucidate the pathogenesis of these disorders and eventually offer a better prognosis for affected patients.

Emergence of Letermovir-resistant HCMV UL56 mutant during rescue treatment in a liver transplant recipient with ganciclovir-resistant infection HCMV: a case report.

BACKGROUND: Human Cytomegalovirus (HCMV) still represents a crucial concern in solid organ transplant recipients (SOTRs) and the use of antiviral therapy are limited by side effects and the selection of viral mutations conferring antiviral drug resistance. CASE PRESENTATION: Here we reported the case of an HCMV seronegative patient with common variable immunodeficiency (CVID), multiple hepatic adenomatosis, hepatopulmonary syndrome and portal hypertension who received a liver transplant from an HCMV seropositive donor. The patient was treated with Valganciclovir (vGCV) and then IV Ganciclovir (GCV) at 5 week post-transplant for uncontrolled HCMV DNAemia. However, since mutation A594V in UL97 gene conferring resistance to ganciclovir was reported, GCV therapy was interrupted. Due to the high toxicity of Foscarnet (FOS) and Cidofovir (CDV), Letermovir (LMV) monotherapy at the dosage of 480 mg per day was administered, with a gradual viral load reduction. However, a relapse of HCMV DNAemia revealed the presence of mutation C325Y in HCMV UL56 gene conferring resistance to LMV. CONCLUSIONS: In conclusion, even if LMV is an effective and favorable safety molecule it might have a lower genetic barrier to resistance. A warning on the use of LMV monotherapy as rescue treatments for HCMV GCV-resistant infections in transplant recipients is warranted.

Consensus of the Italian Primary Immunodeficiency Network on transition management from pediatric to adult care in patients affected with childhood-onset inborn errors of immunity.

Medical advances have dramatically improved the long-term prognosis of children and adolescents with inborn errors of immunity (IEIs). Transfer of the medical care of individuals with pediatric IEIs to adult facilities is also a complex task because of the large number of distinct disorders, which requires involvement of patients and both pediatric and adult care providers. To date, there is no consensus on the optimal pathway of the transitional care process and no specific data are available in the literature regarding patients with IEIs. We aimed to develop a consensus statement on the transition process to adult health care services for patients with IEIs. Physicians from major Italian Primary Immunodeficiency Network centers formulated and answered questions after examining the currently published literature on the transition from childhood to adulthood. The authors voted on each recommendation. The most frequent IEIs sharing common main clinical problems requiring full attention during the transitional phase were categorized into different groups of clinically related disorders. For each group of clinically related disorders, physicians from major Italian Primary Immunodeficiency Network institutions focused on selected clinical issues representing the clinical hallmark during early adulthood.