Cytomegalovirus in the transplant setting: Where are we now and what happens next? A report from the International CMV Symposium 2021.

The CMV Symposium in September 2021 was an international conference dedicated to cytomegalovirus (CMV) infection after solid organ or hematopoietic stem cell transplantation. This review provides an overview of the presentations given by the expert faculty, supplemented with educational clinical cases. Topics discussed include CMV epidemiology and diagnosis, the burden of CMV infection and disease, CMV-specific immunity and management of CMV in transplant settings. Major advances in the prevention and treatment of CMV in the past decade and increased understanding of CMV immunity have led to improved patient outcomes. In the future, management algorithms may be individualized based on the transplant recipient's immune profile, which will mark the start of a new era for patients with CMV.

Executive Summary of the Consensus Document on the Diagnosis and Management of Patients with Primary Immunodeficiencies.

Primary immunodeficiencies (PIDs) are rare, undiagnosed and potentially fatal diseases. Clinical manifestations of PID can be fatal or leave sequelae that worsen the quality of life of patients. Traditionally, the treatment of PIDs has been largely supportive, with the exception of bone marrow transplantation and, more recently, gene therapy. The discovering of new affected pathways, the development of new molecules and biologics, and the increasing understanding of the molecular basis of these disorders have created opportunities in PIDs therapy. This document aims to review current knowledge and to provide recommendations about the diagnosis and clinical management of adults and children with PIDs based on the available scientific evidence taking in to account current practice and future challenges. A systematic review was conducted, and evidence levels based on the available literature are given for each recommendation where available.

Executive Summary of the Consensus Document on the Diagnosis and Management of Patients with Primary Immunodeficiencies.

Primary immunodeficiencies (PIDs) are rare, undiagnosed and potentially fatal diseases. Clinical manifestations of PID can be fatal or leave sequelae that worsen the quality of life of patients. Traditionally, the treatment of PIDs has been largely supportive, with the exception of bone marrow transplantation and, more recently, gene therapy. The discovering of new affected pathways, the development of new molecules and biologics, and the increasing understanding of the molecular basis of these disorders have created opportunities in PIDs therapy. This document aims to review current knowledge and to provide recommendations about the diagnosis and clinical management of adults and children with PIDs based on the available scientific evidence taking in to account current practice and future challenges. A systematic review was conducted, and evidence levels based on the available literature are given for each recommendation where available.

The Expanding Field of Secondary Antibody Deficiency: Causes, Diagnosis, and Management.

Antibody deficiency or hypogammaglobulinemia can have primary or secondary etiologies. Primary antibody deficiency (PAD) is the result of intrinsic genetic defects, whereas secondary antibody deficiency may arise as a consequence of underlying conditions or medication use. On a global level, malnutrition, HIV, and malaria are major causes of secondary immunodeficiency. In this review we consider secondary antibody deficiency, for which common causes include hematological malignancies, such as chronic lymphocytic leukemia or multiple myeloma, and their treatment, protein-losing states, and side effects of a number of immunosuppressive agents and procedures involved in solid organ transplantation. Secondary antibody deficiency is not only much more common than PAD, but is also being increasingly recognized with the wider and more prolonged use of a growing list of agents targeting B cells. SAD may thus present to a broad range of specialties and is associated with an increased risk of infection. Early diagnosis and intervention is key to avoiding morbidity and mortality. Optimizing treatment requires careful clinical and laboratory assessment and may involve close monitoring of risk parameters, vaccination, antibiotic strategies, and in some patients, immunoglobulin replacement therapy (IgRT). This review discusses the rapidly evolving list of underlying causes of secondary antibody deficiency, specifically focusing on therapies targeting B cells, alongside recent advances in screening, biomarkers of risk for the development of secondary antibody deficiency, diagnosis, monitoring, and management.

Monitoring of early humoral immunity to identify lung recipients at risk for development of serious infections: A multicenter prospective study.

BACKGROUND: Infection is still a leading cause of death during the first year after lung transplantation. We performed a multicenter study among teaching hospitals to assess monitoring of early humoral immunity as a means of identifying lung recipients at risk of serious infections. METHODS: We prospectively analyzed 82 adult lung recipients at 5 centers in Spain. Data were collected before transplantation and at 7 and 30 days after transplantation. Biomarkers included IgG, IgM, IgA, complement factors C3 and C4, titers of antibodies to pneumococcal polysaccharide antigens (IgG, IgA, IgM) and antibodies to cytomegalovirus (IgG), and serum B-cell activating factor (BAFF) levels. The clinical follow-up period lasted 6 months. Clinical outcomes were bacterial infections requiring intravenous anti-microbial agents, cytomegalovirus (CMV) disease, and fungal infections requiring therapy. RESULTS: We found that 33 patients (40.2%) developed at least 1 serious bacterial infection, 8 patients (9.8%) had CMV disease, and 10 patients (12.2%) had fungal infections. Lower IgM antibody levels against pneumococcal polysaccharide antigens at Day 7 (defined as <5 mg/dl) were a risk factor for serious bacterial infection (adjusted odds ratio [OR] 3.96; 95% confidence interval [CI] 1.39 to 11.26; p = 0.0099). At Day 7 after transplantation, IgG hypogammaglobulinemia (defined as IgG <600 mg/dl) was associated with a higher risk of CMV disease (after adjustment for CMV mismatch: OR 8.15; 95% CI 1.27 to 52.55; p = 0.028) and fungal infection (adjusted OR 8.03, 95% CI 1.51 to 42.72; p = 0.015). Higher BAFF levels before transplantation were associated with a higher rate of development of serious bacterial infection and acute cellular rejection. CONCLUSION: Early monitoring of specific humoral immunity parameters proved useful for the identification of lung recipients who are at risk of serious infections.

Evaluation of humoral immunity profiles to identify heart recipients at risk for development of severe infections: A multicenter prospective study.

BACKGROUND: New biomarkers are necessary to improve detection of the risk of infection in heart transplantation. We performed a multicenter study to evaluate humoral immunity profiles that could better enable us to identify heart recipients at risk of severe infections. METHODS: We prospectively analyzed 170 adult heart recipients at 8 centers in Spain. Study points were before transplantation and 7 and 30 days after transplantation. Immune parameters included IgG, IgM, IgA and complement factors C3 and C4, and titers of specific antibody to pneumococcal polysaccharide antigens (anti-PPS) and to cytomegalovirus (CMV). To evaluate potential immunologic mechanisms leading to IgG hypogammaglobulinemia, before heart transplantation we assessed serum B-cell activating factor (BAFF) levels using enzyme-linked immunoassay. The clinical follow-up period lasted 6 months. Clinical outcome was need for intravenous anti-microbials for therapy of infection. RESULTS: During follow-up, 53 patients (31.2%) developed at least 1 severe infection. We confirmed that IgG hypogammaglobulinemia at Day 7 (defined as IgG <600 mg/dl) is a risk factor for infection in general, bacterial infections in particular, and CMV disease. At Day 7 after transplantation, the combination of IgG <600 mg/dl + C3 <80 mg/dl was more strongly associated with the outcome (adjusted odds ratio 7.40; 95% confidence interval 1.48 to 37.03; p = 0.014). We found that quantification of anti-CMV antibody titers and lower anti-PPS antibody concentrations were independent predictors of CMV disease and bacterial infections, respectively. Higher pre-transplant BAFF levels were a risk factor of acute cellular rejection. CONCLUSION: Early immunologic monitoring of humoral immunity profiles proved useful for the identification of heart recipients who are at risk of severe infection.

The Immunology of Posttransplant CMV Infection: Potential Effect of CMV Immunoglobulins on Distinct Components of the Immune Response to CMV.

The immune response to cytomegalovirus (CMV) infection is highly complex, including humoral, cellular, innate, and adaptive immune responses. Detection of CMV by the innate immune system triggers production of type I IFNs and inflammatory cytokines which initiate cellular and humoral responses that are critical during the early viremic phase of CMV infection. Sustained control of CMV infection is largely accounted for by cellular immunity, involving various T-cell and B-cell subsets. In solid organ transplant patients, global suppression of innate and adaptive immunities by immunosuppressive agents limits immunological defense, including inhibition of natural killer cell activity with ongoing lowering of Ig levels and CMV-specific antibody titers. This is coupled with a short-term suppression of CMV-specific T cells, the extent and duration of which can predict risk of progression to CMV viremia. CMV immunoglobulin (CMVIG) preparations have the potential to exert immunomodulatory effects as well as providing passive immunization. Specific CMVIG antibodies and virus neutralization might be enhanced by modulation of dendritic cell activity and by a decrease in T-cell activation, effects which are of importance during the initial phase of infection. In summary, the role of CMVIG in reconstituting specific anti-CMV antibodies may be enhanced by some degree of modulation of the innate and adaptive immune responses, which could help to control some of the direct and indirect effects of CMV infection.

Potential role of serum BAFF as a biomarker in HIV infection.

We evaluated the potential role of serum B-cell activating factor (BAFF) as a biomarker in HIV infection and analyzed the relationship between BAFF concentration and the immunophenotypic activation status of T-cells. We tested the hypothesis that higher serum BAFF concentrations are associated with risk for development of AIDS in HIV positive individuals. Forty-one HIV patients (CDC category A 17, category B 24) were evaluated retrospectively. Serum BAFF concentrations were assessed using a commercial enzyme-linked immunosorbent assay. Cox regression was used to estimate the probability for development of AIDS. Patients with higher BAFF concentrations (> 2100 pg/mL) were at greater risk of developing AIDS (relative hazard 5.69; p = 0.0033). BAFF levels were independently associated with risk of AIDS after adjustment by clinical risk factors. Serum BAFF was correlated with activated T-cell subsets and with neopterin levels. BAFF is a good candidate for further evaluation as a nonspecific surrogate marker in HIV infection.

Altered microRNA expression after infection with human cytomegalovirus leads to TIMP3 downregulation and increased shedding of metalloprotease substrates, including MICA.

Proteolytic shedding of ligands for the NK group 2D (NKG2D) receptor is a strategy used by tumors to modulate immune recognition by NK cells and cytotoxic T cells. A number of metalloproteases, especially those of the A disintegrin and metalloprotease (ADAM) family, can mediate NKG2D ligand cleavage and this process can be modulated by expression of the thiol isomerase ERp5. In this article, we describe that an increased shedding of the NKG2D ligand MICA is observed postinfection with several strains of human CMV due to an enhanced activity of ADAM17 (TNF-α converting enzyme) and matrix metalloprotease 14 caused by a reduction in the expression of the endogenous inhibitor of metalloproteases tissue inhibitors of metalloproteinase 3 (TIMP3). This decrease in TIMP3 expression correlates with increased expression of a cellular miRNA known to target TIMP3, and we also identify a human CMV-encoded microRNA able to modulate TIMP3 expression. These observations characterize a novel viral strategy to influence the shedding of cell-surface molecules involved in immune response modulation. They also provide an explanation for previous reports of increased levels of various ADAM17 substrates in the serum from patients with CMV disease. Consistent with this hypothesis, we detected soluble MICA in serum of transplant recipients with CMV disease. Finally, these data suggest that it might be worthwhile to prospectively study ADAM17 activity in a larger group of patients to assay whether this might be a useful biomarker to identify patients at risk for development of CMV disease.

Alterations of naïve and memory B-cell subsets are associated with risk of rejection and infection in heart recipients.

Rejection and infection are relevant causes of mortality in heart recipients. We evaluated the kinetics of the maturation status of B lymphocytes and its relationship with acute cellular rejection and severe infection in heart recipients. We analyzed B-cell subsets using 4-color flow cytometry in a prospective follow-up study of 46 heart recipients. Lymphocyte subsets were evaluated at specific times before and up to 1 year after transplantation. Higher percentages of pretransplant class-switched memory B cells (CD19+CD27+IgM-IgD- >14%) were associated with a 74% decrease in the risk of severe infection [Cox regression relative hazard (RH) 0.26, 95% confidence interval (CI), 0.07-0.86; P = 0.027]. Patients with higher percentages of naïve B cells at day 7 after transplantation (CD19+CD27-IgM+IgD+ >58%) had a 91% decrease in the risk of developing acute cellular rejection (RH 0.09; 95% CI, 0.01-0.80; P = 0.02). Patients with infections showed a strong negative correlation between baseline serum B-cell-activating factor (BAFF) concentration and absolute counts of memory class-switched B cells (R = -0.81, P = 0.01). The evaluation of the immunophenotypic maturation status of B lymphocytes could prove to be a useful marker for identifying patients at risk of developing rejection or infection after heart transplantation.

Prostatic aspergillosis in a heart transplant recipient: case report and review.

In this study we report the first case of invasive prostatic aspergillosis (IPRA) in a heart recipient with post-transplantation antibody deficiency, and review the other 11 cases described in the medical literature. Seven patients were immunocompromised and 6 had dissemination to other sites. Examination of the prostate usually revealed enlargement, with or without nodular lesions. Transrectal ultrasonography or computed tomography scan can provide the diagnosis, although this should be confirmed with biopsy and culture of the lesion. Urine culture can be negative and treatment should include long-term systemic anti-fungal therapy and, in most cases, prostatectomy.

Quantitative abnormalities of peripheral blood distinct T, B, and natural killer cell subsets and clinical findings in obstetric antiphospholipid syndrome.

OBJECTIVE: Few studies have assessed immunophenotypic abnormalities on lymphocyte subsets in patients with antiphospholipid syndrome (APS). We performed an extended immunological study to define alterations of distinct T, B, and natural killer (NK) cell subsets in obstetric patients with APS and their relationship with APS-associated complications. PATIENTS AND CONTROLS: 36 women with APS [Sydney criteria, Group A1 without thrombosis (n=26), Group A2 with thrombosis (n=10)]; and 36 age matched women with recurrent abortion without antiphospholipid antibodies (disease controls; Group B), 36 healthy parous women (healthy controls; Group C), and 36 healthy nonparous women (healthy controls; Group D). Thrombotic events occurred after history of abortions in all A2 women. Three-color whole-blood flow cytometry was used to characterize the distinct immunophenotypes. RESULTS: A1 patients had significantly higher percentages of CD4+CD45RA-CCR7+ central memory cells (A1 vs D), higher percentages of activated CD4+CD25+ T cells (A1 vs D), and lower percentages and absolute counts of CD4+CD45RA-CCR7- effector memory cells (A1 vs D). Group A2 patients had higher percentages and absolute numbers of CD19+CD27-IgD+ naive B cells (A2 vs A1 vs all controls), lower percentages and absolute numbers of CD3-CD56+CD16+ NK cells (A2 vs all controls), and higher percentages of activated CD4+DR+ (A2 vs all controls), CD8+DR+ (A2 vs A1 vs C vs D), CD4+CD38+DR+ (A2 vs D), and CD4+CD25+DR+ T cells (A2 vs all controls). Increased percentages of CD8+DR+ T cells [relative risk (RR) 2.43, 95% CI 1.09-5.44, p=0.02] and of naive B cells (RR 3.05, 95% CI 1.30-7.11, p=0.009) were associated with development of thrombosis. CONCLUSION: In obstetric patients with APS we documented significant changes in T, B, and NK cell homeostasis. Increased levels of CD8+DR+ and CD19+CD27-IgD+ cells might identify obstetric patients with APS at risk of having thrombosis.

Infectious pulmonary complications in patients treated with anti-TNF-alpha monoclonal antibodies and soluble TNF receptor.

Tumor necrosis factor (TNF)-alpha inhibitors (infliximab, adalimumab, and etanercept) used in immune-mediated inflammatory diseases such as rheumatoid arthritis, Crohn's disease, or psoriatic arthritis have the potential to increase the risk of infectious complications. Pulmonary infections are one of the most frequent complications associated with the use of TNF inhibitors. This article provides an overview of the distinct types of infectious pulmonary complications seen in patients using these anticytokine drugs.

[Mixed cryoglobulinemia and related immunological disorders after hepatic transplantation for hepatitis C cirrhosis. Case report]. / Crioglobulinemia mixta y otras alteraciones inmunologicas en trasplante hepatico por cirrosis por virus de la hepatitis C. Reporte de un caso.

Cryoglobulinemia may be found in up to 30% of patients that had received liver transplants after hepatitis C virus (HCV) cirrhosis. Three types of cryoglobulinemia are recognized: type I, composed of monoclonal immunoglobulins associated with lymphoproliferative diseases and myeloma; type II cryoglobulinemia are comprised of a monoclonal component which has rheumatoid factor activity and hence binds to polyclonal immunoglobulins (in certain parts of the world have been found to be associated with hepatitis C infection); and type III cryoglobulinemia consist exclusively of polyclonal immunoglobulins with rheumatoid factor activity (associated with connective tissue diseases and chronic infections including hepatitis C). Immunocompetence, autoimmunity and clonal expansion of B cell lymphocytes have not been analysed simultaneously in previous reports of patients with cryoglobulinemia after liver transplantation. We here describe immunological abnormalities associated with cryoglobulinemia in a patient who had received liver transplant for HCV cirrhosis. In addition, in the present work HCV RNA determination was performed directly in the cryocrit and not only in peripheral blood. We have observed enrichment of HCV RNA in the cryoprecipitates which might be a better demonstration of the possible role of HCV in the pathogenesis of the cryoglobulinemia.