High BMP4 expression in low/intermediate risk BCP-ALL identifies children with poor outcomes.

Pediatric B-cell precursor acute lymphoblastic leukemia (BCP-ALL) outcome has improved in the last decades, but leukemic relapses are still one of the main problems of this disease. Bone morphogenetic protein 4 (BMP4) was investigated as a new candidate biomarker with potential prognostic relevance, and its pathogenic role was assessed in the development of disease. A retrospective study was performed with 115 pediatric patients with BCP-ALL, and BMP4 expression was analyzed by quantitative reverse transcription polymerase chain reaction in leukemic blasts at the time of diagnosis. BMP4 mRNA expression levels in the third (upper) quartile were associated with a higher cumulative incidence of relapse as well as a worse 5-year event-free survival and central nervous system (CNS) involvement. Importantly, this association was also evident among children classified as having a nonhigh risk of relapse. A validation cohort of 236 patients with BCP-ALL supported these data. Furthermore, high BMP4 expression promoted engraftment and rapid disease progression in an NSG mouse xenograft model with CNS involvement. Pharmacological blockade of the canonical BMP signaling pathway significantly decreased CNS infiltration and consistently resulted in amelioration of clinical parameters, including neurological score. Mechanistically, BMP4 favored chemoresistance, enhanced adhesion and migration through brain vascular endothelial cells, and promoted a proinflammatory microenvironment and CNS angiogenesis. These data provide evidence that BMP4 expression levels in leukemic cells could be a useful biomarker to identify children with poor outcomes in the low-/intermediate-risk groups of BCP-ALL and that BMP4 could be a new therapeutic target to blockade leukemic CNS disease.

Monitoring of Serological, Cellular and Genomic Biomarkers in Transplantation, Computational Prediction Models and Role of Cell-Free DNA in Transplant Outcome.

The process and evolution of an organ transplant procedure has evolved in terms of the prevention of immunological rejection with the improvement in the determination of immune response genes. These techniques include considering more important genes, more polymorphism detection, more refinement of the response motifs, as well as the analysis of epitopes and eplets, its capacity to fix complement, the PIRCHE algorithm and post-transplant monitoring with promising new biomarkers that surpass the classic serum markers such as creatine and other similar parameters of renal function. Among these new biomarkers, we analyze new serological, urine, cellular, genomic and transcriptomic biomarkers and computational prediction, with particular attention to the analysis of donor free circulating DNA as an optimal marker of kidney damage.

Early Cytomegalovirus Reactivation in Renal Recipients Is Associated with High Levels of B Cell Maturation Antigen Transcript Expression Prior to Transplantation.

Cytomegalovirus (CMV) infection is the most frequent infection episode in kidney transplant (KT) recipients. Reactivation usually occurs in the first three months after transplantation and is associated with higher cellular and/or antibody-mediated rejection rates and poorer graft performance. CMV induces the expression of BAFF (B-cell-activating factor, a cytokine involved in the homeostasis of B cells), which communicates signals for survival and growth to B cells and virus-specific plasma cells via the R-BAFF (BAFF receptor), TACI (the calcium modulator, the cyclophilin ligand interactor), and BCMA (B cell maturation antigen) receptors. These molecules of the BAFF system have also been suggested as biomarkers for the development of alloantibodies and graft dysfunction. This prospective study included 30 CMV-IgG seropositive KT recipients. The expression levels of the genes BAFF-R, transmembrane activator and CAML interactor (TACI), and B cell maturation antigen (BCMA) in peripheral blood leukocytes (PBL) pre-KT were determined using qPCR. qPCR was also used to monitor CMV reactivation in the first three months following KT. The remainder of the KT recipients were classified as CMV- reactivation, and those with more than 500 copies/mL in at least one sample were classified as CMV+ reactivation. There were no discernible variations in the BAFF-R and TACI transcript expression levels. In the CMV+ group, we examined the relationship between the transcript levels and peak viremia. Peak viremia levels and BCMA transcript levels showed a strong correlation. BAFF-R and TACI expressions showed no measurable differences. In patients with early CMV reactivation, high BCMA receptor expression was associated with increased plasmablast, lymphocyte B cell class-switched levels (LBCS), and viral load. Our findings demonstrate that pre-KT BCMA transcript levels increased in KT recipients with early CMV reactivation. These transcript levels positively correlate with peak viremia and weakly with plasmablast and LBCS levels in PBLs.

Killer Cell Immunoglobulin-like Receptors (KIR) and Human Leucocyte Antigen C (HLA-C) Increase the Risk of Long-Term Chronic Liver Graft Rejection.

Chronic liver rejection (CR) represents a complex clinical situation because many patients do not respond to increased immunosuppression. Killer cell immunoglobulin-like receptors/Class I Human Leukocyte Antigens (KIR/HLA-I) interactions allow for predicting Natural Killer (NK) cell alloreactivity and influence the acute rejection of liver allograft. However, its meaning in CR liver graft remains controversial. KIR and HLA genotypes were studied in 513 liver transplants using sequence-specific oligonucleotides (PCR-SSO) methods. KIRs, human leucocyte antigen C (HLA-C) genotypes, KIR gene mismatches, and the KIR/HLA-ligand were analyzed and compared in overall transplants with CR (n = 35) and no-chronic rejection (NCR = 478). Activating KIR (aKIR) genes in recipients (rKIR2DS2+ and rKIR2DS3+) increased CR compared with NCR groups (p = 0.013 and p = 0.038). The inhibitory KIR (iKIR) genes in recipients rKIR2DL2+ significantly increased the CR rate compared with their absence (9.1% vs. 3.7%, p = 0.020). KIR2DL3 significantly increases CR (13.1% vs. 5.2%; p = 0.008). There was no influence on NCR. CR was observed in HLA-I mismatches (MM). The absence of donor (d) HLA-C2 ligand (dC2-) ligand increases CR concerning their presence (13.1% vs. 5.6%; p = 0.018). A significant increase of CR was observed in rKIR2DL3+/dC1- (p = 0.015), rKIR2DS4/dC1- (p = 0.014) and rKIR2DL3+/rKIR2DS4+/dC1- (p = 0.006). Long-term patient survival was significantly lower in rKIR2DS1+rKIR2DS4+/dC1- at 5-10 years post-transplant. This study shows the influence of rKIR/dHLA-C combinations and aKIR gene-gene mismatches in increasing CR and KIR2DS1+/C1-ligands and the influence of KIR2DS4+/C1-ligands in long-term graft survival.

Activating Killer-Cell Immunoglobulin-Like Receptors Are Associated With the Severity of Coronavirus Disease 2019.

BACKGROUND: Etiopathogenesis of the clinical variability of the coronavirus disease 2019 (COVID-19) remains mostly unknown. In this study, we investigate the role of killer cell immunoglobulin-like receptor (KIR)/human leukocyte antigen class-I (HLA-I) interactions in the susceptibility and severity of COVID-19. METHODS: We performed KIR and HLA-I genotyping and natural killer cell (NKc) receptors immunophenotyping in 201 symptomatic patients and 210 noninfected controls. RESULTS: The NKcs with a distinctive immunophenotype, suggestive of recent activation (KIR2DS4low CD16low CD226low CD56high TIGIThigh NKG2Ahigh), expanded in patients with severe COVID-19. This was associated with a higher frequency of the functional A-telomeric activating KIR2DS4 in severe versus mild and/or moderate patients and controls (83.7%, 55.7% and 36.2%, P < 7.7 × 10-9). In patients with mild and/or moderate infection, HLA-B*15:01 was associated with higher frequencies of activating B-telomeric KIR3DS1 compared with patients with other HLA-B*15 subtypes and noninfected controls (90.9%, 42.9%, and 47.3%; P < .002; Pc = 0.022). This strongly suggests that HLA-B*15:01 specifically presenting severe acute respiratory syndrome coronavirus 2 peptides could form a neoligand interacting with KIR3DS1. Likewise, a putative neoligand for KIR2DS4 could arise from other HLA-I molecules presenting severe acute respiratory syndrome coronavirus 2 peptides expressed on infected an/or activated lung antigen-presenting cells. CONCLUSIONS: Our results support a crucial role of NKcs in the clinical variability of COVID-19 with specific KIR/ligand interactions associated with disease severity.

Low-affinity immunoglobulin gamma Fc region receptor III-B (FcγRIIIB, CD16B) deficiency in patients with blood and immune system disorders.

Low-affinity immunoglobulin gamma Fc region receptor III-B (FcγRIIIB) deficiency is present in ˜0·05% of the general population. Among our patients, FcγRIIIB deficiency was less frequent in those with immune-system disorders (one of 1815 patients, 0·05%) than in those with blood disorders (nine of 2147 patients, 0·42%, P = 0·023): mainly primary immune thrombocytopenia (4·34%), therapy related myeloid neoplasms (1·16%) and myelodysplastic syndrome with excess blasts (1·28%). Four of the nine (44·4%) patients with blood disorders were diagnosed with or quickly evolved to acute myeloid leukaemia (AML), suggesting that FcγRIIIB deficiency could be an adverse prognostic factor for progression to AML that should be confirmed in large multicentre studies.

The roles of Cdc42 and Rac1 in the formation of plasma membrane protrusions in cancer epithelial HeLa cells.

The inducible model of clones generated from the cervical cancer epithelial HeLa cell line has shown the role of DOCK10 as a guanine-nucleotide exchange factor for Rho GTPases Cdc42 and Rac1 and as an inducer of filopodia and plasma membrane (PM) ruffles. In this model, constitutively active (CA) mutants of Cdc42 and Rac1 promote filopodia and ruffles, respectively, as in other models. DOCK9 also induces filopodia and ruffles, although ruffling activity is less prominent. By exploiting this model further, the aim of this work is to provide a more complete understanding of the role of Cdc42 and Rac1, and their interactions with DOCK10 and DOCK9, in regulation of PM protrusions. New clones have been generated from HeLa, including single clones expressing one form of wild-type (WT) or dominant negative (DN) Cdc42 or Rac1, and double clones co-expressing one of them together with either DOCK10 or DOCK9. Expression of WT- and DN-Cdc42 induced filopodia. WT-Cdc42 and, especially, DN-Cdc42 also gave rise to veil protrusions, which were neutralized by DOCK10. Moreover, DN-Cdc42 stimulated the emergence of ruffles, further increased by DOCK10, and WT-Cdc42 also augmented ruffles in presence of DOCK9 and DOCK10. WT-Rac1 greatly increased PM blebbing, as did DN-Rac1 more moderately. In both cases, blebs were enhanced by DOCK10. DN-Rac1 and CA-Rac1 moderately raised filopodia, and DOCK10 and DOCK9 had opposed effects on filopodia (up and down, respectively) in presence of WT-Rac1. As conclusions, we highlight that Cdc42 promotes filopodia regardless of its conformational state, and Rac1 induces blebs in conformations other than CA, especially WT-Rac1, in the inducible HeLa clones. The model could be useful to learn more about the mechanisms underlying PM protrusions.

Proliferation to Apoptosis Tumor Cell Ratio as a Biomarker to Improve Clinical Management of Pre-Malignant and Symptomatic Plasma Cell Neoplasms.

Proliferation and apoptosis of neoplastic cells are prognostic biomarkers in plasma cell neoplasms (PCNs). The prognostic capacity of proliferation to apoptosis ratio (Ratio-PA) in the era of immunomodulatory treatments is re-evaluated in 316 gammopathy of undetermined significance (MGUS), 57 smoldering multiple myeloma (SMM), and 266 multiple myeloma (MM) patients. Ratio-PA of 0.77 ± 0.12, 1.94 ± 0.52, and 11.2 ± 0.7 (p < 0.0001) were observed in MGUS, SMM, and MM patients. Ten-year overall survival (10y-OS) rates for patients with low/high Ratio-PA were 93.5%/77.3% p < 0.0001) for MGUS, 82.5%/64.7% (p < 0.05) for SMM, and 62.3%/47.0% (p < 0.05) for MM. For patients with low, intermediate, and high risk, 10y-OS for low/high Ratio-PA were 95.5%/72.9% (p < 0.0001), 74.2%/50.4% (p < 0.0001), and 35.3%/20.0% (p = 0.836), respectively. Ratio-PA was an independent prognostic factor for OS (HR = 2.119, p < 0.0001, Harrell-C-statistic = 0.7440 ± 0.0194) when co-analyzed with sex, age, and standard risk. In patients with Ratio-PAhigh, only first-line therapy with VRd/VTd, but not PAD/VCD, coupled with ASCT was associated with high 10y-OS (82.7%). Tumor cell Ratio-PA estimated at diagnosis offers a prognostic biomarker that complements standard risk stratification and helps to guide the clinical management of pre-malignant and symptomatic PCNs. Every effort should be made to provide first-line therapies including VTd or VRd associated with ASCT to patients with Ratio-PAhigh at higher risk of progression and death.

High frequency of central memory regulatory T cells allows detection of liver recipients at risk of early acute rejection within the first month after transplantation.

Several studies have analyzed the potential of T regulatory cells (Treg cells) as biomarkers of acute rejection (AR). The aim of the present multicenter study was to correlate the percentage of peripheral Treg cells in liver graft recipients drawn at baseline up to 12 months after transplantation with the presence of AR. The percentage of central memory (cm) Treg cells (CD4(+)CD25(high)CD45RO(+)CD62L(+)) was monitored at pre-transplant and at 1 and 2 weeks, and 1, 2, 3 and 6 months and 1 year post-transplantation. The same validation standard operating procedures were used in all participating centers. Fifteen patients developed AR (23.4%). Hepatitis C virus recurrence was observed in 16 recipients, who displayed low peripheral blood cmTreg levels compared with patients who did not. A steady increase of cmTregs was observed during the first month after transplantation with statistically significant differences between AR and non-AR patients. The high frequency of memory Treg cells allowed us to monitor rejection episodes during the first month post-transplantation. On the basis of these data, we developed a prediction model for assessing risk of AR that can provide clinicians with useful information for managing patients individually and customizing immunosuppressive therapies.

Killer immunoglobulin-like receptor repertoire analysis in a Caucasian Spanish cohort with inflammatory bowel disease.

Immunological molecules are implicated in inflammatory disorders, including inflammatory bowel disease (IBD; Crohn disease [CD] and ulcerative colitis [UC]). Killer cell immunoglobulin-like receptors (KIRs) are also genetically variable proteins involved in immune function. They are expressed by NK cells and certain T lymphocytes, regulate specificity and function by interaction with HLA Class I molecules, may be either inhibitory or activating and are polymorphic both in terms of alleles and haplotype gene content. Genetic associations between activating KIRs and certain autoimmune and inflammatory diseases have been reported; however, a possible association between KIR and IBD remains unclear. The aim of this study was to determine the relationship between KIR repertoire and IBD pathologies in a Spanish cohort. KIR variability was analyzed using PCR-sequence specific oligonucleotide probes (SSOP). Inhibitory KIR2DL5 was found more frequently in UC and IBD patient groups than in healthy controls (P = 0.028 and P = 0.01, respectively), as was activating KIR2DS1 (P = 0.02, Pc > 0.05, UC vs. Controls; P = 0.001, Pc = 0.01, IBD vs Controls; P = 0.01, Pc > 0.05, Controls vs CR), KIR2DS5 (P = 0.0028, Pc = 0.04, Controls vs UC; P = 0.0001, Pc = 0.0017, Controls vs IBD; P = 0.01, Pc > 0.05, Controls vs CD) and KIR3DS1 (P = 0.012, Pc > 0.05, Controls vs IBD). Our data suggest that imbalance between activating and inhibitory KIR may partially explain the different pathogeneses of these IBDs and that there is a hypothetical role for the telomeric B region (which contains both KIR2DS5 and KIR2DS1) in these diseases.

Measurable residual disease study through three different methods can anticipate relapse and guide early interventions in childhood acute lymphoblastic leukemia.

INTRODUCTION: Acute lymphoblastic leukemia (ALL) is the most common cancer among children. Measurable residual disease (MRD, previously named minimal residual disease) study can guide therapy adjustments or preemptive interventions that might avoid hematological relapse. METHODS: Clinical decision making and patient outcome were evaluated in 80 real-life childhood ALL patients, according to the results observed in 544 bone marrow samples analyzed with three MRD methods: multiparametric flow cytometry (MFC), fluorescent in-situ hybridization (FISH) on B or T-purified lymphocytes and patient-specific nested reverse transcription polymerase chain reaction (RT-PCR). RESULTS: Estimated 5 year overall survival and event-free survival were 94% and 84.1%, respectively. A total of 12 relapses in 7 patients were associated with positive MRD detection with at least one of the three methods: MFC (p < 0.00001), FISH (p < 0.00001) and RT-PCR (p = 0.013). MRD assessment allowed the anticipation of relapse and adapted early interventions with different approaches including chemotherapy intensification, blinatumomab, HSCT and targeted therapy to halt relapse in five patients, although two of them relapsed afterwards. CONCLUSION: MFC, FISH and RT-PCR are complementary methods for MRD monitoring in pediatric ALL. Although, our data clearly show that MDR positive detection is associated with relapse, continuation of standard treatment, intensification or other early interventions were able to halt relapse in patients with different risks and genetic background. More sensitive and specific methods are warranted to enhance this approach. However, whether early treatment of MRD can improve overall survival in patients with childhood ALL needs to be evaluated in adequately controlled clinical trials.

MicroRNAs as Potential Graft Rejection or Tolerance Biomarkers and Their Dilemma in Clinical Routines Behaving like Devilish, Angelic, or Frightening Elements.

Allograft rejection is a widespread complication in allograft recipients with chronic kidney disease. Undertreatment of subclinical and clinical rejection and later post-transplant problems are caused by an imperfect understanding of the mechanisms at play and a lack of adequate diagnostic tools. Many different biomarkers have been analyzed and proposed to detect and monitor these crucial events in transplant outcomes. In this sense, microRNAs may help diagnose rejection or tolerance and indicate appropriate treatment, especially in patients with chronic allograft rejection. As key epigenetic regulators of physiological homeostasis, microRNAs have therapeutic potential and may indicate allograft tolerance or rejection. However, more evidence and clinical validation are indispensable before microRNAs are ready for clinical prime time.

HLA-C*07 is associated with symptomatic HIV-1-associated neurocognitive disorders (HAND) and immune dysregulation.

BACKGROUND: HIV-1-associated neurocognitive disorders (HAND) in stable patients undergoing antiretroviral therapy (ART) may result from ongoing immune dysregulation and chronic inflammation. A contributing factor may result from the unstable HLA class I allele, HLA-C*07. OBJECTIVE: To assess the genetic profile of killer-cell immunoglobulin-like receptors (KIR), human leukocyte antigens (HLA), and immune activation or senescence markers and their association with HAND in stable HIV-1 patients receiving ART. METHODS: An observational cross-sectional study was carried out with 96 patients with asymptomatic or symptomatic HAND. HLA and KIR as well as immune activation/senescence biomarkers in peripheral blood cells were assessed by SSO-Luminex typing and flow cytometry, respectively. RESULTS: HLA-C*07 is associated with symptomatic HAND. The frequency of two copies of HLA-C*07 was higher in patients with symptomatic than with asymptomatic HAND (12.0 vs. 2.2%, ρ < 0.001). The percentage of senescent CD8+CD28- T-cells was higher in patients with two copies of HLA-C*07 (ρ < 0.05). In patients with symptomatic HAND, the percentages of non-senescent CD8+CD28+ T cells were inversely proportional to the number of copies of the HLA-C*07 (ρ < 0.05). CONCLUSION: Patients with symptomatic HAND showed a higher frequency of the homozygotic unstable HLA-C*07 allotype, which could be associated with neurocognitive complications. Two copies of HLA-C*07 were associated with immune senescent T lymphocyte profiles characterized by the loss of CD28 expression.

KIR gene variability in cutaneous malignant melanoma: influence of KIR2D/HLA-C pairings on disease susceptibility and prognosis.

Natural killer and CD8(+) T cells are believed to be involved in the immune protection against melanoma. Their function may be regulated by a group of receptors defined as killer immunoglobulin-like receptors (KIRs) and their cognate HLA class I ligands. In this study, we analyzed the influence of KIR genes and KIR/HLA-I combinations on melanoma susceptibility and/or prognosis in a Spanish Caucasian population. For this purpose, KIR genotyping by PCR-SSP and HLA-C genotyping by reverse PCR-SSO were performed in 187 melanoma patients and 200 matched controls. We found a significantly low frequency of KIR2DL3 in nodular melanoma (NM) patients (P = 0.001) and in ulcerated melanoma patients (P < 0.0001). Similarly, the KIR2DL3/C1 combination was significantly decreased in melanoma patients (Pc = 0.008) and in patients with sentinel lymph node (SLN) melanoma metastasis (Pc = 0.002). Multivariate logistic regression models showed that KIR2DL3 behaves as a protective marker for NM and ulcerated melanoma (P = 0.02, odds ratio (OR) = 0.14 and P = 0.04, OR = 0.28, respectively), whereas the KIR2DL3/C1 pair acts as a protective marker for melanoma (P = 0.017, OR = 0.54), particularly superficial spreading melanoma (P = 0.02, OR = 0.52), and SLN metastasis (P = 0.0004, OR = 0.14). In contrast, the KIR2DL3(-)/C1C2 genotype seems to be correlated with NM and ulceration. We also report that the KIR2DL1(+)/S1(-)/C2C2 genotype is associated with susceptibility to melanoma and SLN metastasis. Altogether, the study of KIR2D genes and HLA-C ligands may help in assessing cutaneous melanoma risk and prognosis.

HLA-DRB1 and HLA-DQB1 genes on susceptibility to and protection from allergic bronchopulmonary aspergillosis in patients with cystic fibrosis.

Allergic bronchopulmonary aspergillosis (ABPA) is a hypersensitivity pulmonary disease that affects both patients with cystic fibrosis (CF) and those with asthma. HLA-DRB1 alleles have previously been associated with ABPA-CF susceptibility; however, HLA-DQB1 allele associations have not been clearly established. The aim of the present study was to investigate HLA class II associations in patients with ABPA-CF and determine their roles in susceptibility or protection. Patients with ABPA-CF, patients with CF without ABPA, patients with asthma without ABPA (AST), and healthy controls were included in this study. DNA was extracted by automatic extractor. HLA-DRB1 and -DQB1 genotyping was performed by the Luminex PCR-SSOP method (One Lambda, Canoga Park, CA, USA). Allele specific PCR-SSP was also performed by high-resolution analysis (One Lambda). Statistical analysis was performed with SSPS and Arlequin software. Both HLA-DRB1*5:01 and -DRB1*11:04 alleles occurred with greater frequency in patients with ABPA-CF than in those with AST and CF and control subjects, corroborating previously published data. On the other hand, analysis of haplotypes revealed that almost all patients with ABPA-CF lacking DRB1*15:01 or DRB1*11:04 carry either DRB1*04, DRB1*11:01, or DRB1*07:01 alleles. In the HLA-DQB1 region, the HLA-DQB1*06:02 allele occurred more frequently in patients with ABPA-CF than in those with AST and CF and healthy controls, whereas HLA-DQB1*02:01 occurred less frequently in patients with ABPA-CF. These data confirm that there is a correlation between HLA-DRB1*15:01, -DRB1*11:04, DRB1*11:01, -DRB1*04 and -DRB1*07:01 alleles and ABPA-CF susceptibility and suggest that HLA-DQB1*02:01 is an ABPA-CF resistance allele.

Role of vaccination and anti-SARS-CoV-2 antibodies in the clinical outcome of hospitalized COVID-19 patients.

BACKGROUND: Although vaccination has considerably reduced the risk of hospitalization and death from COVID19, the impact of vaccination and anti-SARS-CoV-2 antibody status on the outcome of patients who required hospitalization has been poorly investigated. MATERIAL AND METHODS: A prospective observational study in 232 patients hospitalized for COVID19 was carried out from October 2021 to January 2022 to evaluate the role on patient outcome of their vaccination and anti-SARS-CoV-2 antibody status and titer, comorbidities, analytical determinations, clinical presentation at admission, treatments and requirements for respiratory support. Cox regression and survival analyzes were performed. The SPSS and "R" programs were used. RESULTS: Patients with complete vaccination schedule had higher S-protein antibody titers (log10 3.73 [2.83-4.6]UI/ml vs 1.6 [2.99-2.61]UI/ml; p<0.001), lower probability of radiographic worsening (21.6% vs. 35.4%; p=0.005), less likely required high doses of dexamethasone (28.4% vs. 45.4%; p=0.012), high-flow oxygen (20.6% vs. 35.4%; p=0.02), ventilation (13.7% vs, 33.8%; p=0.001) and intensive care admissions (10.8% vs. 32.6%; p<0.001). Remdesivir (HR=0.38; p<0.001) and complete vaccination schedule (HR=0.34; p=0.008) were protective factors. No differences in antibody status were detected between groups (HR=0.58; p=0.219). CONCLUSIONS: SARS-CoV-2 vaccination was associated with higher S-protein antibody titers and lower probability of radiological progression, immunomodulators requirement and respiratory support or death. However, vaccination but not antibody titters protected from adverse events pointing a role of immune-protective mechanisms in addition to humoral response.

Role of vaccination and anti-SARS-CoV-2 antibodies in the clinical outcome of hospitalized COVID-19 patients.

Background: Although vaccination has considerably reduced the risk of hospitalization and death from COVID19, the impact of vaccination and anti-SARS-CoV-2 antibody status on the outcome of patients who required hospitalization has been poorly investigated. Material and methods: A prospective observational study in 232 patients hospitalized for COVID19 was carried out from October 2021 to January 2022 to evaluate the role on patient outcome of their vaccination and anti-SARS-CoV-2 antibody status and titer, comorbidities, analytical determinations, clinical presentation at admission, treatments and requirements for respiratory support. Cox regression and survival analyzes were performed. The SPSS and "R" programs were used. Results: Patients with complete vaccination schedule had higher S-protein antibody titers (log10 3.73 [2.83-4.6] UI/ml vs 1.6 [2.99-2.61] UI/ml; p < 0.001), lower probability of radiographic worsening (21.6% vs. 35.4%; p = 0.005), less likely required high doses of dexamethasone (28.4% vs. 45.4%; p = 0.012), high-flow oxygen (20.6% vs. 35.4%; p = 0.02), ventilation (13.7% vs, 33.8%; p = 0.001) and intensive care admissions (10.8% vs. 32.6%; p < 0.001). Remdesivir (HR = 0.38; p < 0.001) and complete vaccination schedule (HR = 0.34; p = 0.008) were protective factors. No differences in antibody status were detected between groups (HR = 0.58; p = 0.219). Conclusions: SARS-CoV-2 vaccination was associated with higher S-protein antibody titers and lower probability of radiological progression, immunomodulators requirement and respiratory support or death. However, vaccination but not antibody titters protected from adverse events pointing a role of immune-protective mechanisms in addition to humoral response.

Antecedentes: Aunque la vacunación ha reducido considerablemente el riesgo de hospitalización y muerte por COVID-19, se ha investigado poco el impacto de la vacunación y el estado de los anticuerpos anti-SARS-CoV-2 en la evolución de los pacientes que requieren hospitalización. Material y métodos: Se realizó un estudio observacional prospectivo en 232 pacientes hospitalizados por COVID-19 desde octubre del 2021 hasta enero del 2022 para evaluar el impacto en la evolución clínica del estado vacunal, el título de anticuerpos anti-SARS-CoV-2, la presencia de comorbilidades, analítica, la clínica al ingreso, tratamientos y soporte respiratorio. Se realizaron análisis de supervivencia y regresión de Cox. Se utilizaron los programas SPSS y «R¼. Resultados: Los pacientes con esquema de vacunación completo presentaron títulos de anticuerpos contra la proteína S más elevados (log10 3,73 [2,83-4,6] UI/mL vs. 1,6 [2,99-2,61] UI/mL; p < 0,001), menor probabilidad de empeoramiento radiográfico (21,6 vs. 35,4%; p = 0,005), requirieron con menor probabilidad dosis elevadas de dexametasona (28,4 vs. 45,4%; p = 0,012), oxígeno de alto flujo (20,6 vs. 35,4%; p = 0,02), ventilación (13,7 vs. 33,8%; p = 0,001) e ingresos en cuidados intensivos (10,8 vs. 32,6%; p < 0,001). El remdesivir (HR = 0,38; p < 0,001) y el esquema completo de vacunación (HR = 0,34; p = 0,008) fueron factores protectores de mala evolución. No se detectaron diferencias en el estado de los anticuerpos entre los grupos (HR = 0,58; p = 0,219). Conclusiones: La vacunación contra el SARS-CoV-2 se asoció con mayores títulos de anticuerpos contra la proteína S y menor probabilidad de progresión radiológica, requerimiento de inmunomoduladores y soporte respiratorio o muerte. Sin embargo, la vacunación, pero no los títulos de anticuerpos, protegió de los eventos adversos, lo que indica un papel de los mecanismos de protección inmunológica además de la respuesta humoral.

Higher Expression of Activated CD8+ T Lymphocytes (CD8+CD25+, CD8+CD69+ and CD8+CD95+) Mediate Early Post-Transplant Acute Tubular Injury in Kidney Recipients.

BACKGROUND: Acute kidney injury (AKI) is a leading cause of early post-transplant kidney damage. Furthermore, acute tubular necrosis (ATN) is appointed as the most prevalent form of AKI, a frequent multifactorial process associated with high morbidity and mortality, yet giving rise to delayed graft function (DGF) and, ultimately, allograft dysfunction. Common factors such as prolonged cold ischemia time, advanced donor age, cadaveric versus living donor, donor history of hypertension, as well as donation after cardiac death have all been deemed risk factors for ATN. With the increasing number of older cadaveric and cardiac donors in the donation process, ATN could have a detrimental impact on patient welfare. Therefore understanding the underlying process would benefit the transplant outcome. We aimed to prospectively monitor several T cell subsets in a cohort of kidney transplant recipients (KTrs) to investigate whether there is an adaptive immune-mediated involvement in the ATN process. METHODS: Peripheral blood was collected from 31 KTrs at different time points within the first-year post-transplantation for in vitro stimulation with Concanavalin-A (Con-A) in a humidified 5% CO2 incubator at 37 °C for 72 hours. Upon cell stimulation, flow cytometry was applied to quantify the surface expression through the median fluorescence intensity (MFI) of CD4+CD25+, CD8+CD25+, CD4+CD38+, CD8+CD38+, CD4+CD154+, CD8+CD154+, CD4+CD69+, CD8+CD69+, CD4+CD95+, and CD8+CD95+ T cells. Statistical analysis was carried out with SPSS Statistics IBM v.25 (IBM Corp, Armonk, NY, USA). MFIs values were compared using a univariate analysis by a nonparametric U-Mann Whitney test. ROC analysis was applied to define cut-off values most capable of stratifying patients at high risk of ATN. Spearman's rank-order coefficient test was applied to correlate biomarkers with allograft function. Multivariate regression independently validated CD8+ T lymphocytes as surrogate biomarkers of ATN. A p-value < 0.05 was considered statistically significant. RESULTS: KTrs who developed ATN upon transplantation had significantly higher expression of CD25, CD69, and CD95 on CD8+ and lower expression of CD95 on CD4+ T lymphocytes than patients with stable graft function. ROC curve analysis showed that MFIs ≥1015.20 for CD8+CD25+, ≥2489.05 for CD8+CD69+, ≥4257.28 for CD8+CD95+, and ≤1581.98 for CD4+CD95+ were capable of stratifying KTrs at high risk of ATN. Furthermore, patients with an MFI below any cut-off were significantly less likely to develop ATN than those with other values. The allograft function was correlated with the CD4+CD95+/CD8+CD95+ ratio in KTrs who developed ATN. The multivariate analysis confirmed that, within the first-month post-transplant, MFI values of CD8+CD25+, CD4+CD95+, and CD8+CD95+ T lymphocytes, along with donor age, serum creatinine, and GFR were independent risk factors to ATN. Moreover, we were also able to corroborate previous immune factors of importance in immune-mediated response to the allograft, such as the patient's maximum panel reactive antibody (PRA) or the maintenance immunosuppression therapy. CONCLUSIONS: Our results demonstrate evidence for the implication of CD8+ T lymphocytes in the development of ATN early in the post-transplant phase. Post-transplant monitoring of activated CD8+ T lymphocytes may help identify which patients require further clinical intervention to prevent graft damage.

Clinical Significance of the Pre-Transplant CXCR3 and CCR6 Expression on T Cells In Kidney Graft Recipients.

BACKGROUND: T cells play a fundamental role in the processes that mediate graft rejection, tolerance, and defense against infections. The CXCR3 and CCR6 receptors, highly expressed in Th1 (type 1 T helper cells)/Tc1 (T cytotoxic cells, type 1), Th1-Tc1, and Th17-Tc17 lymphocytes, respectively, participate in cell migration toward inflamed tissues. The altered expression level of CXCR3 and CCR6 has been associated with different clinical events after renal transplantation, such as acute rejection (AR) and chronic graft dysfunction, but data are still limited. In this study, we evaluated the expression of the receptor CXCR3 and CCR6 in peripheral blood T lymphocytes from kidney transplant recipients (KTR) and their association with viral infections, AR, and allograft function. METHODS: Through flow cytometry, the peripheral blood expression of CXCR3 and CCR6 in T cells was evaluated in a pretransplant collection of KTR. The levels of these T subpopulations and their association with the incidence of AR, kidney graft function, viral infections, cytomegalovirus, and BK virus were studied. Adverse clinical events and graft function were monitored during the first year post transplant. RESULTS: KTRs with low pretransplantation levels of Th17 (CD4+CXCR3-CCR6+) (tertile 1, Th17<16.4%) had a higher risk of suffering AR during the first year post transplantation (P = .033). KTRs with viral infections or reactivations during the first 3 months post transplantation had significantly lower levels of Tc17 (CD8+CXCR3-CCR6+) and higher levels of Th1 (CD4+CXCR3+CCR6-). In patients with cytomegalovirus reactivations, the viral peak correlates negatively with the pretransplant levels of Th1 (r = -0.606, P = .037). CONCLUSIONS: Pretransplantation assessment of Th1-Th17 and Tc1-Tc17 levels may help predict post-transplant clinical events such as AR and reactivation of viral infections.