Back to basics: likelihood ratios for olive and grass pollen specific IgE in seasonal allergic rhinitis.

Introduction: Specific IgE (sIgE) is merely a sensitization marker that cannot be used for allergy diagnosis if there are no associated clinical symptoms. As of 2023, there is still no evidence regarding the quantity of sIgE necessary to confirm or exclude clinical disease. Therefore, this study aimed to calculate cut-offs for sIgE, allowing us to effectively diagnose olive or grass pollen allergy and select allergenic immunotherapy (AIT) candidate patients in a region under high olive and grass allergenic pressure. Methods: An observational retrospective study consisting of the review of electronic medical records from 1,172 patients diagnosed with seasonal rhino-conjunctivitis and suspected allergy to olive or grass pollen. Symptoms correlated with sIgE to Poaceae and Oleaceae whole extracts and sIgE to genuine allergenic components were evaluated. Optimal cut-off values were calculated using receiver operating characteristic curves. Relevant clinical symptoms and AIT indications were taken into consideration when determining the clinical allergy diagnosis. Results: sIgE to Lolium showed the best area under the curve (AUC) for both diagnosis (0.957) and an indication of AIT (0.872). The optimal cut-off values for grass diagnosis and AIT indication were 1.79 kUA/L and 8.83 kUA/L, respectively. A value of 5.62 kUA/L was associated with a positive likelihood ratio (LR) of 10.08 set for grass allergy. Olea sIgE showed the best AUC for the diagnosis (0.950). The optimal cut-off for diagnosis was 2.41 kUA/L. A value of 6.49 kUA/L was associated with a positive LR of 9.98 to confirm olive pollen allergy. In regard to immunotherapy, Ole e 1 sIgE showed the best AUC (0.860). The optimal cut-off was 14.05 kUA/L. Ole e 1 sIgE value of 4.8 kUA/L was associated with a 0.09 negative LR to exclude olive AIT indication. Conclusions: The sIgE cut-offs found in this population under high olive and grass allergenic pressure reduce the gap between sensitization and clinical allergy, providing a new tool for the diagnosis of seasonal allergic rhinitis/asthma and helping to discriminate patients who will benefit from AIT.

Natural and Induced Tolerance to Hymenoptera Venom: A Single Mechanism?

Inducing tolerance in Hymenoptera-allergic patients, bee venom immunotherapy (BVIT) is a widely accepted method to treat severe allergy to bee stings. In order to increase the existing knowledge on the underlying immunological mechanisms and look for possible biomarkers predictive of efficacy, a group of 20 bee-venom-allergic patients (AG) were thoroughly examined during their first year of BVIT. In addition, the results of treated patients with those of an untreated group of 20 tolerant beekeepers (TG) who had previously shown a firm suppressor-regulatory profile were compared. Tolerance in AG patients was invariably associated with a significant regulatory response characterised by the expansion of Helios- subpopulation and increased IL-10, specific IgG4 (sIgG4), and kynurenine levels. Although specific IgE (sIgE) levels increased transiently, surprisingly, the T helper type 2 (Th2) population and IL-4 levels rose significantly after one year of immunotherapy. Thus, the picture of two parallel phenomena emerges: a tolerogenic response and an allergenic one. Comparing these results with those obtained from the TG, different immunological mechanisms appear to govern natural and acquired tolerance to immunotherapy. Of particular interest, the kynurenine levels and T regulatory (Treg) Helios- population could be proposed as new biomarkers of response to BVIT.

Impact of Cytomegalovirus and Age on T-Cell Subsets Defined by CD161, CD300a, and/or CD57 Expression in Healthy Andalusians.

Immunosenescence affects innate and adaptive immunity impairing the response to pathogens and vaccines. Chronic infection with cytomegalovirus (CMV) has been shown to drive "early immunosenescence" and can considerably affect both the function and phenotype of immune cells, especially T cells. We have previously shown that the expression of CD57, CD300a, and CD161 was differentially affected by age and chronic CMV infection, indicating that these markers are a hallmark of CMV infection and T-cell aging. The aim of this present study was to clarify whether these 3 markers define distinct T-cell subpopulations with a specific functional and molecular signature. Specifically, we analyzed the effect of age and chronic CMV infection on the functionality of T cells according to CD161, CD300a, and CD57 expression. We found that these markers defined different T-cell subsets, both at the phenotypic and functional levels. CD57 was the best biomarker for CD4+ T-cell cytotoxicity and was a hallmark of CMV infection. CD300a+ T cells were heterogeneous and included different cell subsets. The population of CD161+ T cells dramatically decreased with age, independently of CMV infection, and represented a sign of age-associated immune system alterations. The latter could contribute to an increased risk of autoimmune disease and infection in older adults. Our results underline the importance of better understanding the factors involved in the immunosenescence process to be able to uncover new biomarkers and open new avenues for the investigation and development of novel age-related disease therapies.

Characterization of the DNAM-1, TIGIT and TACTILE Axis on Circulating NK, NKT-Like and T Cell Subsets in Patients with Acute Myeloid Leukemia.

Background: Acute myeloid leukemia (AML) remains a major clinical challenge due to poor overall survival, which is even more dramatic in elderly patients. TIGIT, an inhibitory receptor that interacts with CD155 and CD112 molecules, is considered as a checkpoint in T and NK cell activation. This receptor shares ligands with the co-stimulatory receptor DNAM-1 and with TACTILE. The aim of this work was to analyze the expression of DNAM-1, TIGIT and TACTILE in NK cells and T cell subsets in AML patients. Methods: We have studied 36 patients at the time of diagnosis of AML and 20 healthy volunteers. The expression of DNAM-1, TIGIT and TACTILE in NK cells and T cells, according to the expression of CD3 and CD56, was performed by flow cytometry. Results: NK cells, CD56- T cells and CD56+ T (NKT-like) cells from AML patients presented a reduced expression of DNAM-1 compared with healthy volunteers. An increased expression of TIGIT was observed in mainstream CD56- T cells. No differences were observed in the expression of TACTILE. Simplified presentation of incredibly complex evaluations (SPICE) analysis of the co-expression of DNAM-1, TIGIT and TACTILE showed an increase in NK and T cells lacking DNAM-1 and co-expressing TIGIT and TACTILE. Low percentages of DNAM-1-TIGIT+TACTILE+ NK cells and DNAM-1- TIGIT+TACTILE+ CD56- T cells were associated with a better survival of AML patients. Conclusions: The expression of DNAM-1 is reduced in NK cells and in CD4+ and CD8+ T cells from AML patients compared with those from healthy volunteers. An increased percentage of NK and T cells lacking DNAM-1 and co-expressing TIGIT and TACTILE is associated with patient survival, supporting the role of TIGIT as a novel candidate for checkpoint blockade.

Hemodiafiltration with ultrafiltrate regeneration reduces free light chains without albumin loss in multiple myeloma patients.

BACKGROUND: Acute kidney injury (AKI) occurs in 12-20% of multiple myeloma (MM) patients. Several studies have shown a reduction of free light chains (FLC) using hemodialysis with High-Cut-Off membranes. However, this technique entails albumin loss. Hemodiafiltration with ultrafiltrate regeneration is a technique that includes a process of adsorption. The aim of this study was to evaluate the effectiveness of hemodiafiltration with ultrafiltrate regeneration in reducing FLC levels without causing albumin loss. METHODS: This is an observational study (2012 to 2018) including nine patients with MM (5 kappa, 4 lambda) and AKI. All patients were treated with chemotherapy and hemodiafiltration with ultrafiltrate regeneration. Blood Samples (pre and post-dialysis) and ultrafiltrate were collected pre and post-resin at 5 min after initiation of the session and 5 min before the end of the procedure. RESULTS: The serum levels of kappa and lambda were reduced by a 57.6 ± 10% and 33.5 ± 25% respectively. Serum albumin concentration remained unchanged after the procedure. In the ultrafiltrate, the mean FLC reduction ratio shortly after initiation of the dialysis procedure was: 99.2 and 97.06% for kappa and lambda respectively, and only 0.7% for albumin; and at the end of the session the percent reduction was: 63.7 and 33.62% for kappa and lambda respectively, and 0.015% for albumin. Patients clinical outcome was: 33.3% recovered renal function, 22.2% died during the first year and 44.4% required maintenance dialysis. CONCLUSIONS: Hemodiafiltration with ultrafiltrate regeneration reduces FLC levels without producing a significant loss of albumin; and, FLC removal is maintained throughout the session. Therefore, hemodiafiltration with ultrafiltrate regeneration may be considered an effective adjunctive therapy in patients with MM.

Current progress in NK cell biology and NK cell-based cancer immunotherapy.

A better understanding of the complex interactions between the immune system and tumour cells from different origins has opened the possibility to design novel procedures of antitumoral immunotherapy. One of these novel approaches is based on the use of autologous or allogeneic natural killer (NK) cells to treat cancer. In the last decade, different strategies to activate NK cells and their use in adoptive NK cell-based therapy have been established. Although NK cells are often considered as a uniform cell population, several phenotypic and functionally distinct NK cells subsets exist in healthy individuals, that are differentially affected by ageing or by apparently innocuous viruses such as cytomegalovirus (CMV). In addition, further alterations in the expression of activating and inhibitory receptors are found in NK cells from cancer patients, likely because of their interaction with tumour cells. Thus, NK cells represent a promising strategy for adoptive immunotherapy of cancer already tested in phase 1/2 clinical trials. However, the existence of NK cell subpopulations expressing different patterns of activating and inhibitory receptors and different functional capacities, that can be found to be altered not only in cancer patients but also in healthy individuals stratified by age or CMV infection, makes necessary a personalized definition of the procedures used in the selection, expansion, and activation of the relevant NK cell subsets to be successfully used in NK cell-based immunotherapy.

Characterization of the C1q-Binding Ability and the IgG1-4 Subclass Profile of Preformed Anti-HLA Antibodies by Solid-Phase Assays.

Humoral alloimmunity, particularly that triggered by preformed antibodies against human leukocyte antigens (HLA), is associated with an increased prevalence of rejection and reduced transplant survival. The high sensitivity of solid phase assays, based on microbeads coated with single antigens (SAB), consolidated them as the gold-standard method to characterize anti-HLA antibodies, ensuring a successful allograft allocation. Mean fluorescence intensity (MFI) provided by SAB is regularly used to stratify the immunological risk, assuming it as a reliable estimation of the antibody-level, but it is often limited by artifacts. Beyond MFI, other properties, such as the complement-binding ability or the IgG1-4 subclass profile have been examined to more accurately define the clinical relevance of antibodies and clarify their functional properties. However, there are still unresolved issues. Neat serum-samples from 20 highly-sensitized patients were analyzed by SAB-panIgG, SAB-IgG1-4 subclass and SAB-C1q assays. All 1:16 diluted serum-samples were additionally analyzed by SAB-panIgG and SAB-IgG1-4 subclass assays. A total of 1,285 anti-HLA antibodies were identified as positive, 473 (36.8%) of which were C1q-binding. As expected, serum-dilution enhanced the correlation between the C1q-binding ability and the antibody-strength, measured as the MFI (rneat = 0.248 vs. rdiluted = 0.817). SAB-subclass assay revealed at least one IgG1-4 subclass in 1,012 (78.8%) positive antibody-specificities. Among them, strong complement-binding subclasses, mainly IgG1, were particularly frequent (98.9%) and no differences were found between C1q- and non-C1q-binding antibodies regarding their presence (99.4 vs. 98.5%; p = 0.193). In contrast, weak or non-C1q-binding subclasses (IgG2/IgG4) were more commonly detected in C1q-binding antibodies (78.9 vs. 38.6%; p < 0.001). Interestingly, a strong association was found between the C1q-binding ability and the IgG1 strength (rIgG1dil = 0.796). Though lower, the correlation between the IgG2 strength and the C1q-binding ability was also strong (rIgG2dil = 0.758), being both subclasses closely related (rIgG1-IgG2 = 0.817). We did not find any correlation with the C1q-binding ability considering the remaining subclasses. In conclusion, we demonstrate that a particular profile of IgG subclasses (IgG1/IgG3) itself does not determine at all the ability to bind complement of anti-HLA antibodies assessed by SAB-C1q assay. It is the IgG subclass strength, mainly of IgG1, which usually appears in combination with IgG2, that best correlates with it.

DNAM-1 and the TIGIT/PVRIG/TACTILE Axis: Novel Immune Checkpoints for Natural Killer Cell-Based Cancer Immunotherapy.

Natural killer (NK) cells are lymphocytes of the innate immune response characterized by their role in the destruction of tumor cells. Activation of NK cells depend on a fine balance between activating and inhibitory signals mediated by different receptors. In recent years, a family of paired receptors that interact with ligands of the Nectin/Nectin-like (Necl) family has attracted great interest. Two of these ligands, Necl-5 (usually termed CD155 or PVR) and Nectin-2 (CD112), frequently expressed on different types of tumor cells, are recognized by a group of receptors expressed on T and NK cells that exert opposite functions after interacting with their ligands. These receptors include DNAM-1 (CD226), TIGIT, TACTILE (CD96) and the recently described PVRIG. Whereas activation through DNAM-1 after recognition of CD155 or CD112 enhances NK cell-mediated cytotoxicity against a wide range of tumor cells, TIGIT recognition of these ligands exerts an inhibitory effect on NK cells by diminishing IFN-γ production, as well as NK cell-mediated cytotoxicity. PVRIG has also been identified as an inhibitory receptor that recognizes CD112 but not CD155. However, little is known about the role of TACTILE as modulator of immune responses in humans. TACTILE control of tumor growth and metastases has been reported in murine models, and it has been suggested that it negatively regulates the anti-tumor functions mediated by DNAM-1. In NK cells from patients with solid cancer and leukemia, it has been observed a decreased expression of DNAM-1 that may shift the balance in favor to the inhibitory receptors TIGIT or PVRIG, further contributing to the diminished NK cell-mediated cytotoxic capacity observed in these patients. Analysis of DNAM-1, TIGIT, TACTILE and PVRIG on human NK cells from solid cancer or leukemia patients will clarify the role of these receptors in cancer surveillance. Overall, it can be speculated that in cancer patients the TIGIT/PVRIG pathways are upregulated and represent novel targets for checkpoint blockade immunotherapy.

Modulation of NK cells with checkpoint inhibitors in the context of cancer immunotherapy.

The incidence of some types of tumours has increased progressively in recent years and is expected to continue growing in the coming years due in part to the aging of the population. The design of new therapies based on natural killer (NK) cells opens new possibilities especially for the treatment of elderly patients who are particularly susceptible to the toxicity of conventional chemotherapy treatments. In recent years, the potential use of NK cells in cancer immunotherapy has been of great interest thanks to advances in the study of NK cell biology. The identification of key points (checkpoints) in the activation of NK cells that can be regulated by monoclonal antibodies has allowed the design of new therapeutic strategies based on NK cells. However, there are still limitations for its use and the first clinical trials blocking KIR inhibitory receptors have shown little efficacy by inhibiting the maturation of NK cells. Blockade of other inhibitory receptors such as TIGIT, TIM3, LAG3 and PD1 may represent novel strategies to increase NK function in cancer patients. Altogether, the identification of NK cell and tumour cell markers of resistance or susceptibility to the action of NK cells will contribute to identifying those patients that will most likely benefit from NK cell-based immunotherapy.

Comparación de dos métodos para la cuantificación en suero de subclases de inmunoglobulinas / Comparison of two methods for the quantification of immunoglobulin subclasses in serum samples

Antecedentes y objetivo: La determinación de inmunoglobulinas en suero y, concretamente de IgG y de subclases de IgG, es fundamental para el diagnóstico clínico de numerosas patologías. Los métodos de detección habituales proporcionan resultados diferentes según el analizador utilizado. El objetivo de este estudio fue comparar los resultados obtenidos mediante dos analizadores diferentes para la concentración de IgG y de subclases de IgG. Materiales y métodos: Se analizaron un total de 116 muestras de suero, independientemente del diagnóstico clínico de los pacientes a los que pertenecían dichas muestras. Los análisis se realizaron sobre las plataformas BNII(R) System (Siemens Healthcare GmbH, Alemania) y Optilite(R) (The Binding Site Group Ltd., Birmingham). Resultados: La correlación entre la concentración de IgG total (mg/dl) y el sumatorio de las concentraciones de subclases de IgG detectadas de manera individual fue mayor usando el analizador Optilite(R) (0,976 vs. 0,866). El porcentaje de concordancia varió del 43% hasta 71%, siendo el límite inferior para la concordancia de IgG3. Se detectó una ausencia de la proporción fisiológica normal de subclases de IgG (IgG1>IgG2>IgG3>IgG4) al utilizar BNII(R). Dichos resultados fueron consecuencia de que la concentración de IgG3 por BNII(R) fue significativamente inferior a la obtenida por Optilite(R) (p<0,001), mientras que la concentración de IgG4 no fue significativamente diferente entre analizadores (p=0,117). Conclusiones: Las diferencias existentes entre los resultados obtenidos por ambos métodos analíticos utilizados sugieren que dichos ensayos no deben ser intercambiables, sino que cada laboratorio debe utilizar un único analizador y estandarizar los rangos de referencia según sus resultados

Background and aim: The quantification of serum immunoglobulins, and particularly of IgG and IgG subclasses, is of interest for the diagnosis of numerous diseases. The usual detection methods provide different results according to the analyser used. The aim of this study was to compare the results obtained with two different analysers in the measurement of the concentration of IgG and IgG subclasses. Material and methods: A total of 116 serum samples, regardless of the clinical diagnosis of the patients to whom the samples belonged, were analysed. The analyses were performed on a BNII(R) System (Siemens Healthcare GmbH, Germany) and Optilite(R) system (The Binding Site Group Ltd., Birmingham). Results: The correlation between total IgG concentration (mg/dl) and the sum of the individual IgG subclasses detected was higher using the Optilite(R) analyser (0.976 vs. 0.866). The percentage of agreement between assays ranged from 43% to 71%, with the lower limit being for the IgG3 agreement. An absence of the usual IgG subclass physiological proportion (IgG1>IgG2>IgG3>IgG4) was detected using BNII(R). These findings were a due to the significantly lower proportion of IgG3 obtained by BNII(R) compared to Optilite(R) (P<.001), whereas the IgG4 concentration was not significantly different between analysers (P=.117). Conclusions: Differences between the results obtained with the two different methods suggest that they should not be interchangeable, and that each clinical laboratory should only use one type of analyser. The reference ranges should be standardised according to the results obtained

Effect of Age on NK Cell Compartment in Chronic Myeloid Leukemia Patients Treated With Tyrosine Kinase Inhibitors.

Natural killer (NK) cells are a very important component of the innate immune response involved in the lysis of virus infected and tumor cells. Aging has a profound impact in the frequency, phenotype and function of NK cells. Chronic Myeloid Leukemia (CML) is caused by the BCR-ABL gene formation encoding aberrant oncoprotein tyrosine kinase. Treatment with tyrosine kinase inhibitors (TKIs) induces durable deep molecular response. The response to treatment and life expectancy is lower in older patients with chronic phase of CML than in younger patients. In this work we analyse NK cells from TKI-treated CML patients and healthy controls stratified according to age. We have analyzed the expression of NK receptors, activation markers, NK cell differentiation in CD56bright and CD56dim NK cell subsets and the expression of CD107a and IFN-γ in NK cells stimulated with K562. Whereas significant differences on the phenotype and function of NK cells were found between middle-aged (35-65 years old) and elderly (older than 65) healthy individuals, NK cells from TKI-treated CML patients do not show significant differences related with age in most parameters studied, indicating that age is not a limitation of the NK cell recovery after treatment with TKI. Our results also revealed differences in the expression of NK receptors, activation markers and functional assays in NK cells from TKI-treated CML patients compared with age-matched healthy controls. These results highlight the relevance of NK cells in TKI-treated patients and the need of an extensive analysis of the effect of aging on NK cell phenotype and function in these patients in order to define new NK-cell based strategies directed to control CML progression and achieve long-term disease remission after TKI cessation.

Impact of Preformed Donor-Specific Anti-Human Leukocyte Antigen Antibody C1q-Binding Ability on Kidney Allograft Outcome.

The consolidation of single antigen beads (SAB-panIgG) assay in the detection of preformed anti-human leukocyte antigen (HLA) antibodies has improved transplantation success. However, its high sensitivity has limited the allograft allocation for sensitized patients, increasing their waiting time. A modification of the standard SAB-panIgG assay allows the detection of that subset of antibodies capable of binding C1q (SAB-C1q assay). However, the clinical usefulness of SAB-C1q assay for determining the unacceptable mismatches is under discussion. We retrospectively analyzed the impact of preformed donor-specific anti-HLA antibodies (DSA) according to the C1q-binding ability on allograft outcome, examining 389 single-kidney transplanted patients from deceased donors. Recipients with preformed C1q-binding DSA showed the lowest allograft survival up to 7 years (40.7%) compared to patients with preformed non-C1q-binding DSA (73.4%; p = 0.001) and without DSA (79.1%; p < 0.001). Allograft survival rate was similar between patients with preformed non-C1q-binding DSA and patients without preformed DSA (p = 0.403). Interestingly, among the high-mean fluorescence intensity DSA (≥10,000) population (n = 46), those patients whose DSA were further capable of binding C1q showed a poorer allograft outcome (38.4 vs. 68.9%; p = 0.041). Moreover, in our multivariate predictive model for assessing the risk of allograft loss, the presence of C1q-binding DSA (HR 4.012; CI 95% 2.326-6.919; p < 0.001) but not of non-C1q-binding DSA (HR 1.389; CI 95% 0.784-2.461; p = 0.260) remained an independent predictor after stratifying the DSA population according to the C1q-binding ability and adjusting the model for other pre-transplantation predictive factors including donor age, cold-ischemia time, and HLA-DR mismatches. In conclusion, the unacceptable mismatch definition according to the SAB-C1q assay would improve the risk stratification of allograft loss and increase the limited allograft allocation of highly sensitized patients, shortening their waiting time.

Effect of age and latent CMV infection on CD8+ CD56+ T cells (NKT-like) frequency and functionality.

Changes in the T cell pool caused by CMV infection have been proposed to contribute to immunosenescence, but it has been postulated that CMV can also have some beneficial effects in young individuals improving the immune response to other pathogens. T cells expressing CD56 (NKT-like cells) are cytotoxic effector cells with a significant role in the immune response against cancer. We have studied how age and latent CMV infection affect the frequency of NKT-like cells (CD8+ CD56+ T cells) and their response to Staphylococcal Enterotoxin B (SEB) in the context of CMV and ageing. NKT-like cell percentage increases with the combination of both CMV and age. The response to SEB and the polyfunctional index of NKT-like cells also increase with age in CMV-seropositive individuals. In young individuals, CMV infection induces a shift on the polyfunctional profile of CD8+ CD56- T cells not observed on the NKT-like cells response. NKT-like cells expressing CD57 are expanded in CMV-seropositive individuals and are more polyfunctional than their CD57- counterpart. In addition CD57- NKT-like cells are more polyfunctional than CD8+ CD56- CD57- T cells. The results support that the expansion of polyfunctional NKT-cells may have a beneficial effect on the immune response against pathogens.

Immunosenescence: Implications for response to infection and vaccination in older people.

People aged 60 and older represent over 11% of the world population and it is expected to rise 22% by 2050. Population aging is associated to an increased frequency of age-related diseases including higher susceptibility to infections, cancer, cardiovascular and neurodegenerative diseases. Immunosenescence refers to the decline of the immune system associated to aging. It affects both, innate and adaptive immunity limiting the response to pathogens and to vaccines. The analyses of the immune system in elderly individuals determined several immune signatures constituting an immune risk phenotype that predicts mortality. An inverse CD4/CD8 ratio, loss of naïve T cells, increased numbers of terminally-differentiated T cells and oligoclonal expansions of virus-specific T cells constitute hallmarks of immunosenescence. Natural killer (NK) cells are also found severely altered in the elderly. The contribution of latent cytomegalovirus infection to immunosenescence of T and NK cells has been shown. Considering the worldwide ageing of the population in the next decades, the impact of infections will be a real health problem for older individuals requiring preventive strategies. Thus, further studies are required to analyse the bases of immunosenescence and to establish protocols to overcome the age-associated alterations of the immune response in order to define effective vaccines against those pathogens, such as influenza, contributing to increased morbidity and mortality in the elderly.

Proinflammatory status influences NK cells subsets in the elderly.

Aging is associated to dysfunctional changes in the immune system, a process termed immunosenescence. Elderly individuals usually present chronic low level inflammation, likely as the consequence of continued exposure to antigens combined with poor immune function, increases in production of pro-inflammatory cytokines by effector memory and senescent T cells and macrophages. This condition not only results from, but also drives immunosenescence. Aging affects all cell components of the immune system, including NK cells and its different subsets (CD56dimCD16+, CD56brightCD16+/- and CD56-CD16+). In particular, the percentage of total NK cells is increased in healthy aging and centenarians, whereas there is a decrease in the CD56bright NK cell subset and an expansion of CD56-CD16+ NK cells. However, the causes of these alterations on NK cells in old donors are not fully understood. In this work we analyse NK cell subsets in the elderly in relation with markers of inflammation and health status. The results show that there is a positive correlation between the number of total NK cells and the body mass index (BMI), while the number of CD56bright NK cells negatively correlates with the levels of C-reactive protein (CRP), supporting that chronic inflammation is involved in the decrease of this NK cell subset.

Effect of age and CMV on NK cell subpopulations.

NK cells represent an important component of the innate immune response against infection and tumors. Age-associated changes in NK cell phenotype have been previously reported that can be responsible of functional NK cell deficiency. The aim of this work was to analyze the effect CMV seropositivity and aging on the distribution of NK cell subsets with a focus on the expression of cytotoxicity-related molecules and on the expression of CD94/NKG2 heterodimers and CD57 on these NK cell subsets. Our results show that CMV seropositivity in young individuals does not significantly affect peripheral blood NK cell percentage and NK cell subsets defined by the use of CD56 and CD16 markers. In contrast a significant increase in the percentage of NK cells is observed in elderly donors, all of them are CMV seropositive, when compared with young CMV seropositive subjects. A decrease in the percentage of CD56bright NK cells, either fully immature CD16 negative or CD16+ and an increase in the CD56-CD16+ subset are also found in the elderly. CMV seropositivity either in healthy young or elderly individuals is associated to the expression of CD94/NKG2C dimers and high expression of CD57on the CD56dimCD16+ NK cell subset. CD56-CD16+ NK cells, which are expanded in the elderly, show a decreased expression of granzymes A and B and an increased expression of CD94/NKG2C and CD57 in CMV seropositive young donors when compared with CMV seronegative young individuals. These results indicate that CMV and age have a different effect on NK cell phenotype and emphasize the relevance of including the determination of CMV serostatus in those studies addressed to analyze the immune response in the elderly.

Eficacia de la hemodiafiltración con regeneración del ultrafiltrado en la reducción de cadenas ligeras en mieloma múltiple con insuficiencia renal / Effectiveness of haemodiafiltration with ultrafiltrate regeneration in the reduction of light chains in multiple myeloma with renal failure

El fracaso renal agudo en el mieloma múltiple (MM) ocurre en un 12-20 % y es un factor de mal pronóstico para la supervivencia del paciente. Estudios recientes muestran que la diálisis con membrana "High-Cut-Off" (HCO) depura eficazmente las cadenas ligeras libres (CLL), aunque con gran pérdida de albúmina. Otras técnicas basadas en la adsorción, como la hemodiafiltración con regeneración del ultrafiltrado mediante adsorción en resina (HFR SUPRA), no han sido estudiadas. Se presentan tres casos de MM, dependientes de hemodiálisis desde el diagnóstico: dos son IgG kappa y uno IgA lambda. Los tres recibieron quimioterapia y HFR SUPRA. El objetivo del estudio fue evaluar la eficacia de la HFR SUPRA en la reducción de CLL, así como su efecto sobre la albúmina. Se obtuvieron muestras sanguíneas pre y posdiálisis y muestras de ultrafiltrado (UF) pre y posresina a los 5 minutos de empezar la sesión y 5 minutos antes de finalizar. La tasa de reducción media por sesión de CLL en sangre en los tres pacientes fue del 53 % y del 63 % (kappa) y del 38 % (lambda). En el UF la tasa de reducción media de CLL fue cercana al 99 %, tanto al inicio como al final de la diálisis, sin eliminación de albúmina. Con los resultados obtenidos podemos concluir que con esta técnica se consigue una reducción eficaz de las CLL, que se mantiene durante toda la sesión, sin que se produzca saturación de la resina y sin pérdida de albúmina. Por tanto, la HFR SUPRA es eficaz como tratamiento coadyuvante del MM (AU)

Acute kidney failure in multiple myeloma (MM) occurs in 12%-20% of patients and is a poor prognostic factor for patient survival. Recent studies have shown that dialysis with a High-Cut-Off membrane (HCO) removes free light chains (FLC) effectively although with significant albumin loss. Other adsorption-based techniques, such as haemodiafiltration with ultrafiltrate regeneration by adsorption in resin (SUPRA-HFR), have not been studied. We present three cases of MM, all haemodialysis-dependent since diagnosis. Two cases were IgG kappa and one was IgA lambda. All patients were treated with chemotherapy and SUPRA-HFR. The aim of this study was to evaluate the effectiveness of SUPRA-HFR in the reduction of FLC and its effect on albumin. We collected blood samples pre- and post-dialysis, and ultrafiltrate (UF) samples pre- and post-resin 5 minutes into the session and 5 minutes from the end. The mean reduction rate of FLC in blood per session in the three patients was 53% and 63% (kappa) and 38% (lambda). In the UF, the mean FLC reduction rate was close to 99%, both at the start and at the end of dialysis, without the removal of albumin. With the results obtained we can conclude that this technique achieves an effective reduction of FLC, which is maintained throughout the session, without resin saturation and without albumin loss. Therefore, SUPRA-HFR is effective as an adjunctive therapy for MM (AU)

Effectiveness of haemodiafiltration with ultrafiltrate regeneration in the reduction of light chains in multiple myeloma with renal failure.

Acute kidney failure in multiple myeloma (MM) occurs in 12%-20% of patients and is a poor prognostic factor for patient survival. Recent studies have shown that dialysis with a High-Cut-Off membrane (HCO) removes free light chains (FLC) effectively although with significant albumin loss. Other adsorption-based techniques, such as haemodiafiltration with ultrafiltrate regeneration by adsorption in resin (SUPRA-HFR), have not been studied. We present three cases of MM, all haemodialysis-dependent since diagnosis. Two cases were IgG kappa and one was IgA lambda. All patients were treated with chemotherapy and SUPRA-HFR. The aim of this study was to evaluate the effectiveness of SUPRA-HFR in the reduction of FLC and its effect on albumin. We collected blood samples pre- and post-dialysis, and ultrafiltrate (UF) samples pre- and post-resin 5 minutes into the session and 5 minutes from the end. The mean reduction rate of FLC in blood per session in the three patients was 53% and 63% (kappa) and 38% (lambda). In the UF, the mean FLC reduction rate was close to 99%, both at the start and at the end of dialysis, without the removal of albumin. With the results obtained we can conclude that this technique achieves an effective reduction of FLC, which is maintained throughout the session, without resin saturation and without albumin loss. Therefore, SUPRA-HFR is effective as an adjunctive therapy for MM.

Immunosenescence of human natural killer cells.

Natural killer (NK) cells are a key component of innate immunity involved not only in the elimination of virus-infected or tumor cells but also in the regulation of the immune response by producing cytokines and chemokines that can activate other cellular components of innate and adaptive immunity. NK cell subsets are differentially affected by aging. Whereas CD56(bright) cells are decreased in healthy elderly individuals, the CD56(dim) subset is expanded. The expression of CD57, a marker of highly differentiated NK cells, is increased in the elderly; this supports the notion that a remodeling process of NK cell subsets occurs in aging with a gradual decrease in more immature CD56(bright) NK cells and an increase in highly differentiated CD56(dim) CD57+ NK cells. This NK cell redistribution can explain many of the phenotypic and functional changes in NK cells associated with healthy aging such as decreased proliferation and the maintenance of CD16-dependent cytotoxicity.

Effect of ageing on CMV-specific CD8 T cells from CMV seropositive healthy donors.

BACKGROUND: Ageing is associated with changes in the immune system with substantial alterations in T-lymphocyte subsets. Cytomegalovirus (CMV) is one of the factors that affect functionality of T cells and the differentiation and large expansions of CMV pp65-specific T cells have been associated with impaired responses to other immune challenges. Moreover, the presence of clonal expansions of CMV-specific T cells may shrink the available repertoire for other antigens and contribute to the increased incidence of infectious diseases in the elderly. In this study, we analyse the effect of ageing on the phenotype and frequency of CMV pp65-specific CD8 T cell subsets according to the expression of CCR7, CD45RA, CD27, CD28, CD244 and CD85j. RESULTS: Peripheral blood from HLA-A2 healthy young, middle-aged and elderly donors was analysed by multiparametric flow cytometry using the HLA-A*0201/CMV pp65(495-504) (NLVPMVATV) pentamer and mAbs specific for the molecules analysed. The frequency of CMV pp65-specific CD8 T cells was increased in the elderly compared with young and middle-aged donors. The proportion of naïve cells was reduced in the elderly, whereas an age-associated increase of the CCR7(null) effector-memory subset, in particular those with a CD45RA(dim) phenotype, was observed, both in the pentamer-positive and pentamer-negative CD8 T cells. The results also showed that most CMV pp65-specific CD8 T cells in elderly individuals were CD27/CD28 negative and expressed CD85j and CD244. CONCLUSION: The finding that the phenotype of CMV pp65-specific CD8 T cells in elderly individuals is similar to the predominant phenotype of CD8 T cells as a whole, suggests that CMV persistent infections contributes to the age-related changes observed in the CD8 T cell compartment, and that chronic stimulation by other persistent antigens also play a role in T cell immunosenescence. Differences in subset distribution in elderly individuals showing a decrease in naive and an increase in effector-memory CD8 T cells may be relevant in the age-associated defective immune response.