Indoleamine, 2-3 dioxygenase activity could be an early marker of graft rejection in heart transplantation

[Abstract] Background. The indoleamine, 2-3 dioxygenase (IDO) is an inducible intracellular enzyme with immunosuppressive effects mainly on lymphocyte populations. It has been postulated that indirect determination of IDO serum activity may be a marker of renal graft rejection, but its potential usefulness in heart transplantation (HT) is unknown. Methods. This longitudinal study included 98 HT patients (83% males) who survived ≥1 year. Mean age was 54.14 ± 11.57 years. Serum IDO activity was analyzed one month after HT by means of high performance liquid chromatography and correlated with the cumulative incidence of acute rejection (AR) during one-year follow-up. AR was defined as biopsy-proven ≥ ISHLT grade 2R rejection or empirically treated non-biopsy-proven rejection. The study sample was divided into two groups: AR group (n = 51), including patients who experienced at least one AR episode during the first year after HT; No-AR group (N = 47), including the remaining patients. Results. Mean serum IDO activity one month after HT was significantly higher (P = .021) in the AR group (3.32 ± 1.56) than in the no-AR group (2.62 ± 1.35). No significant association between serum IDO activity and gender (male: 3.1 ± 1.56, women: 2.43 ± 0.99, P = .092), recipient age (r = −.07, P = .943) or donor age (r = 0.108, P = 0.293) was observed. By means of binary logistic regression, an odds ratio of 1.4 [CI 95%: 1.033-1.876, P = .03] per unit increase of act-IDO was estimated, with no significant modification upon forced adjustment for age and sex. Mean glomerular filtration rate 1 month after HT was 67.01 ± 28.51 mL/min/m2. No significant correlation between this parameter and serum IDO activity was observed (r = .160, P = .117). Conclusions. Our study suggests that serum IDO activity one month after HT might be associated with a higher risk of AR during one-year follow-up. This association seems to be independent of recipient gender, age or renal function

Circulating miR-181a-5p as a new biomarker for acute cellular rejection in heart transplantation

[Abstract] Background: Acute cellular rejection (ACR) is a major complication in heart transplantation (HTx). Endomyocardial biopsy is the reference method for early detection of ACR, but a new non-invasive approach is needed. Tentative candidates could be circulating microRNAs. This study aimed to discover and validate microRNAs in serum for ACR detection after HTx. Methods: This prospective, observational, single-center study included 121 HTx patients. ACR was graded according to International Society of Heart and Lung Transplantation classification (0R−3R). First, in the discovery phase, microRNA expression profile was carried out in serum samples from patients at pre-rejection, during, and post-rejection time (0RS1 → 2RS2 → 0RS3). Relative expression (2-ΔCq) of 179 microRNAs per sample was analyzed by reverse transcription quantitative polymerase chain reaction. Second, a microRNA with a significant rise and fall pattern during ACR was selected for the next validation phase, where it was analyzed (reverse transcription quantitative polymerase chain reaction) in serum samples from 2 groups of patients: the no-ACR group (0R grade) and the ACR group (≥2R grade). Finally, a sensitivity analysis (receiver operating characteristic curve) was done to assess microRNA accuracy for ACR detection in HTx. Results: A total of 21 ACR episodes (0RS1 → 2RS2 → 0RS3) with their respective serum samples (n = 63) were included in the discovery phase. Among the 179 microRNAs analyzed, only miR-181a-5p met the rise and fall criteria. In the validation phase, miR-181a-5p relative expression (2-ΔCq) in the ACR group (n = 45) was significantly overexpressed (p < 0.0001) vs the no-ACR group (n = 45). miR-181a-5p showed an area under the curve of 0.804 (95% confidence interval: 0.707-0.880); sensitivity and specificity of 78% and 76%, respectively; and a negative predicted value of 98%.Instituto de Salud Carlos III; PI15/0222

Polymorphisms in genes related to the complement system and antibody-mediated cardiac allograft rejection

[Abstract] Background. Heart transplantation (HT) is a life-saving treatment for patients with end-stage heart failure. One of the main problems after HT is the humoral response termed antibody-mediated rejection (AMR). Complement activation plays a key role in AMR contributing to graft damage. The aim of this study was to analyze genetic variants in genes related to the complement pathways that could be associated with the development of AMR. Methods. Analysis of 51 genes related to the complement pathway was performed by next-generation sequencing in 46 HT recipients, 23 with and 23 without AMR. Statistical analysis was performed with SNPstats and R. Results. We identified 2 single nucleotide polymorphisms, 1 in the mannose-binding lectin 2 gene (p.Gly54Asp-MBL2) and 1 in the complement factor properdin gene (p.Asn428(p=)-CFP), that showed significant association with the absence and development of AMR, respectively. Moreover, the presence of the rare allele in p.Gly54Asp-MBL2 control patients correlated with an immunodeficiency of mannose-binding lectin (6.24 ng/ml vs 207.50 ng/ml, p < 0.01), whereas the presence of the rare allele p.Asn428(p=)-CFP in patients with AMR correlated with higher levels of properdin protein (14.65 μg/ml vs 10.77 μg/ml, p < 0.05). Conclusions. AMR is a complex phenotype affected by many recipient factors. Variants in p.Gly54Asp-MBL2 and p.Asn428(p=)-CFP genes, encoding mannose-binding lectin 2 and properdin, may influence the risk of AMR.Instituto de Salud Carlos III; PI13/0217

Amiloidosis cardiaca por cadenas ligeras y por transtirretina: características clínicas, historia natural y predictores pronósticos

[Abstract] Introduction and objectives. Light-chain amyloidosis (AL-CA) and transthyretin amyloidosis (ATTR-CA) are the most common types of cardiac amyloidosis (CA). We sought to study the clinical characteristics and prognosis of both diseases. Methods. We conducted a single-centre, retrospective review of all patients diagnosed with CA between 1998 and 2018. Clinical characteristics, complementary tests, survival and other adverse clinical events were studied. Results. We identified 105 patients with CA, 65 ATTR-CA and 40 AL-CA. Mean age was 74.4 years; 24.8% were women. In both groups, heart failure was the most frequent clinical presentation (55.2%). The most prevalent electrocardiographic findings were the pseudoinfarct pattern (68.5%) and a Sokolow-Lyon index <1.5 mV (67.7%), with no differences between the two subtypes of CA. One-year, 3-year, and 5-year survival was 43.3%, 40.4% and 35.4%, respectively, in AC-AL patients, and 85.1%, 57.3% and 31.4% in AC-ATTR patients (p = .004). AL-CA subtype (HR 3.41, CI95% 1.45−8.06, p = .005), previous admission for heart failure (HR 4.25, 95% CI 1.63−11.09, p = .003) and a NYHA class III-IV (HR 2.76, 95% CI 1.09−7.03, p = .033) were independent predictors of mortality, while beta-blocker therapy was associated with longer survival (HR .23, 95% CI .09–.59, p = .002). Conclusions. Differences exist between the clinical presentation of AL-CA and ATTR-CA patients. Both diseases, particularly AL-CA, are associated with poor life prognosis.[Resumen] Antecedentes y objetivos. La amiloidosis cardiaca (AC) por cadenas ligeras (AC-AL) y por transtirretina (AC-ATTR) son los dos subtipos más frecuentes de la enfermedad. Nos propusimos caracterizar clínicamente estas entidades y analizar su pronóstico. Material y métodos. Realizamos una revisión retrospectiva de todos los pacientes diagnosticados de AC entre 1998 y 2018 en un centro español. Además de recoger las características clínicas y los resultados de las pruebas complementarias al diagnóstico, analizamos la supervivencia y la incidencia de desenlaces clínicos adversos. Resultados. Identificamos 105 pacientes con AC, 65 AC-ATTR y 40 AC-AL. La edad media era de 74,4 años; el 24,8% eran mujeres. En ambos grupos la insuficiencia cardiaca (IC) fue la forma de presentación clínica más frecuente (55,2%). Los hallazgos electrocardiográficos más prevalentes fueron el patrón de pseudoinfarto (68,5%) y un índice de Sokolow-Lyon <1,5 mV (67,7%), sin diferencias entre los dos subtipos. La supervivencia a 1, 3 y 5 años fue del 43,3%, 40,4% y 35,4%, respectivamente, en pacientes con AC-AL y de 85,1%, 57,3% y 31,4% en pacientes con AC-ATTR (p = 0,004). El subtipo AC-AL (HR 3,41, IC95% 1,45-8,06, p = 0,005), el ingreso previo por IC (HR 4,25, IC95% 1,63-11,09, p = 0,003) y una clase NYHA III-IV (HR 2,76, IC95% 1,09-7,03, p = 0,033) fueron predictores independientes de mortalidad, mientras que el tratamiento betabloqueante se asoció con una mayor supervivencia (HR 0,23, IC95% 0,09-0,59, p = 0,002). Conclusiones. Existen ciertas diferencias en la presentación clínica de los pacientes con AC-AL y AC-ATTR. Ambas entidades, y muy especialmente la AC-AL, presentan un pobre pronóstico vital

Galectina-3 circulante tras el trasplante cardiaco: dinámica a largo plazo y valor pronóstico

[Abstract] Introduction and objectives: Circulating galectin-3 (Gal-3) is elevated and significantly correlates with all-cause and cardiovascular mortality in patients with heart failure. However, the relationship between serum Gal-3 and heart transplant (HT) outcomes is unclear. The aim of this study was to describe the longitudinal trend and prognostic value of Gal-3 levels after HT. Methods: Banked serum samples were available from 122 HT recipients, collected before transplant and at 1, 3, 6, and 12 months posttransplant. Gal-3 levels in these serum samples were measured by enzyme immune assay. Multivariable Cox regression was performed to determine the prognostic value of 12-month posttransplant Gal-3 serum levels. The primary endpoint was the composite variable all-cause death or graft failure over long-term posttransplant follow-up. Results: Circulating Gal-3 concentration steadily decreased during the first year after HT (median values: pretransplant, 19.1 ng/mL; 1-year posttransplant, 14.6 ng/mL; P<.001). Circulating Gal-3 levels 1-year posttransplant were associated with an increased risk of all-cause death or graft failure (adjusted HR per 1 ng/mL, 1.04; 95%CI, 1.01-1.08; P=.008). The predictive accuracy of this biomarker was moderate: area under the ROC curve, 0.72 (95%CI, 0.60-0.82; P<.001). Conclusions: Circulating Gal-3 steadily decreased during the first year after HT. However, 1-year posttransplant Gal-3 serum levels that remained elevated were associated with increased long-term risk of death and graft failure.[Resumen] Introducción y objetivos. Los valores plasmáticos de galectina-3 (Gal-3) están elevados y se correlacionan con la mortalidad total y cardiovascular en pacientes con insuficiencia cardiaca, pero su correlación con el pronóstico tras el trasplante cardiaco (TxC) es desconocida. El objetivo fue describir la tendencia evolutiva y el valor pronóstico de este biomarcador tras el TxC. Métodos. Mediante enzimoinmunoensayo, se midieron las concentraciones plasmáticas de Gal-3 en muestras de suero de 122 receptores de TxC, antes y 1, 3, 6 y 12 meses después de este. Mediante regresión de Cox se analizó el valor pronóstico del valor plasmático de Gal-3 a los 12 meses del TxC. El objetivo primario del estudio fue la variable combinada muerte o disfunción del injerto. Resultados. Las concentraciones de Gal-3 disminuyeron progresivamente durante el primer año tras el TxC (medianas: pretrasplante, 19,1 ng/ml; 1 año postrasplante, 14,6 ng/ml; p < 0,001). Los valores de Gal-3 1 año tras el TxC se asociaron con mayor riesgo de muerte o disfunción del injerto (HR por 1 ng/ml: 1.04; IC95%: 1,01-1,08; p = 0,008). La capacidad predictiva del biomarcardor fue moderada: área bajo la curva ROC, 0,72 (IC95%: 0,60-0,82; p < 0,001). Conclusiones. Las concentraciones plasmáticas de Gal-3 disminuyeron progresivamente durante el primer año tras el TxC. Un valor plasmático elevado de Gal-3 1 año tras el TxC se correlacionó con un pronóstico adverso.Instituto de Salud Carlos III; PI12/0267