Browsing by Author "Labarca, Cristian"
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Item Efficacy of Methotrexate in Real-world Management of Giant Cell Arteritis: A Case-control Study(2019) Koster, Matthew; Yeruva, Karthik; Crowson, Cynthia S.; Muratore, Francesco; Labarca, Cristian; Warrington, Kenneth J.Objective: To determine the effect of methotrexate (MTX) on relapse risk and glucocorticoid (GC) use in a large single-institution cohort of patients with giant cell arteritis (GCA). Methods: Patients diagnosed with GCA from 1998 to 2013 with confirmed evidence of temporal artery biopsy and/or radiographic evidence of large vessel vasculitis were identified. Each patient with GCA treated with adjunct MTX (case) was matched to a similar patient with GCA treated only with GC (control). GC requirements and relapse events before and after MTX initiation (or corresponding index date) were compared using rate ratios (RR). Results: Eighty-three cases and 83 controls were identified and compared. No significant differences in age, demographics, laboratory variables, baseline disease characteristics, or mean initial prednisone doses were observed. Median [interquartile range (IQR)] time from GCA diagnosis to MTX initiation in cases was 39 (13-80) weeks and the median (IQR) starting dose was 13.5 (10-15) mg/week. RR comparing relapse rates before and after MTX initiation/index date were significantly reduced in both cases (RR 0.32, 95% CI 0.24-0.41) and controls (RR 0.60, 95% CI 0.43-0.86). The decrease in relapse rate was significantly greater in patients taking MTX than in those taking GC alone (p = 0.004). Rates of GC discontinuation did not differ between groups. Conclusion: In this large single-institution cohort, the addition of MTX to GC decreased the rate of subsequent relapse by nearly 2-fold compared to patients taking GC alone. MTX may be considered as adjunct therapy in patients with GCA to decrease the risk of further relapse events.Publication Enfermedad relacionada a IgG4. Serie clínica de pacientes chilenos(2022) Cuéllar, María C.; Gutiérrez, Miguel; Herrera, Alejandra; Elgueta, Fabián; Wurmann, Pamela; Badilla, Natalia; Mansilla, Bellanides; Basualdo, Javier; Vega, Jorge; Erlij, Daniel; Labarca, Cristian; Vergara, Cristian; Mezzano, Verónica; Méndez, Ignacio; Stange, Lilith; Michalland, Susana; Silva, Francisco; Jara, Aquiles; Goecke, Annelise; Burgos, Paula; Iruretagoyena, Mirentxu; Fernández, Cristina; Landeros, Carolina; Neira Quiroga, OscarBackground: IgG4-related disease (IgG4 RD) is an immune-mediated fibro-inflammatory disorder, with tissue infiltration of IgG4+ plasma cells. It causes pseudotumors, tumors, and a wide spectrum of clinical manifestations. Aim: To report the clinical, laboratory, histopathological and treatment characteristics of a group of Chilean patients with IgG4 RD. Material and Methods: Review of medical records of 52 patients aged 18 to 76 years with IgG4 RD seen at six medical centers. Results: Elevated IgG4 serum levels (> 135 mg/dl) were found in 18 of 44 (41%) patients. There was histological confirmation of the disease in 46 patients. The most common sites of involvement were lungs, eyes and kidneys. Eighteen (35%) patients had only one organ involved, 34 (65%) patients had two organs and 13 (25%) patients had three or more organs. The involvement of two organs was significantly more common in men (p < 0.05). In patients with only one organ involvement, the most frequent location was orbital and meningeal. All patients with kidney or lung disease had multiorgan involvement. All patients received corticosteroid therapy, 67% synthetic immunosuppressants, and 16% rituximab. Conclusions: ER-IgG4 can affect any tissue. Multiorgan involvement was more common in this series, with preference for lungs, eyes and kidneys. An excellent response to steroids is characteristic of the disease, but with a high relapse rate that requires additional immunosuppression.Item Giant cell arteritis and its mimics: A comparison of three patient cohorts(2020) Koster, Matthew; Yeruva, Karthik; Crowson, Cynthia S; Muratore, Francesco; Labarca, Cristian; Warrington, Kenneth JObjective: To compare temporal artery biopsy (TAB)-positive giant cell arteritis (GCA) to TAB-negative GCA and patients with GCA mimics METHODS: PATIENTS DIAGNOSED WITH TAB-POSITIVE AND TAB-NEGATIVE GCA BETWEEN 1/1/1998 AND 12/31/2013 WERE: retrospectively identified. These two groups were compared to a cohort of patients with TAB performed between 1/1/2009 and 12/31/2010 in which the TAB was negative and alternative diagnosis was provided after a minimum of 6-months of follow-up. Baseline characteristics were compared between groups using chi-square and rank sum tests. Results: 591 study subjects were identified (286 TAB-positive, 110 TAB-negative GCA and 195 TAB-negative GCA mimics) during the respective study periods. Compared to TAB-negative GCA, GCA mimics had similar rates of headache and vision loss but significantly less frequent jaw/limb claudication, arterial bruits and constitutional symptoms, as well as lower platelet levels. Compared to TAB-positive GCA patients, TAB-negative GCA were younger, had shorter time to diagnosis, met fewer 1990 ACR classification criteria and had lower frequencies of polymyalgia rheumatica, jaw claudication and temporal artery abnormalities; but, higher frequency of arm claudication and constitutional symptoms. Among 61 TAB-negative patients with advanced arterial imaging, 43 (69%) had at least one abnormality consistent with GCA. Conclusion: Consideration of alternative diagnoses is requisite in evaluating patients with negative TAB. Advanced imaging assists in identifying occult large-vessel vasculitis and should be employed in all TAB-negative patients with suspicion for GCA.Publication Modelo de escenarios de simulación para el entrenamiento de razonamiento clínico en estudiantes de medicina(2023) Armijo-Rivera, Soledad; Labarca, Cristian; Pérez Villalobos, Cristian; Behrens Pérez, Claudia; Tamburrino Díaz, Catalina; Castro Pérez, Javiera; Díaz Guío, AndrésIntroducción: El razonamiento clínico es una tarea compleja que los médicos utilizan al momento de enfrentarse a los pacientes. Se puede llevar a cabo a través del sistema intuitivo y el analítico. La simulación clínica es una herramienta para entrenar el razonamiento clínico, sin embargo, su evaluación sigue siendo un desafío. En el presente estudio, se evaluó el formato de diseño de escenarios para razonamiento clínico, asociado al uso de una pauta de observación aplicada en estudiantes de medicina en dos escenarios de simulación secuenciales. Material y Métodos: Se diseñaron dos escenarios de simulación con 4 niveles de complejidad para el manejo de sepsis en paciente adulto, donde participaron 12 grupos de 8 estudiantes. Estas simulaciones fueron grabadas y posteriormente analizadas por observadores calificados a través de una pauta de observación de escenario basada en las propuestas conceptuales de Croskerry, Braun y Pennaforte. Resultados: Los escenarios se llevaron a cabo en un promedio de 12 minutos. La mayoría logró establecer el diagnóstico e instauración de manejo inicial a través de la recogida parcial de información, dando cuenta del dominio del razonamiento intuitivo en el 98 % de los casos, sin embargo, solo el 10,4 % utilizó el sistema analítico. Conclusión: El diseño de escenarios de simulación compuestos de distintos niveles de complejidad podría promover el desarrollo del razonamiento clínico. La utilización de una pauta de observación del escenario permitió el análisis del proceso del razonamiento clínico en un entorno realista y sin interrupciones, y podría ser utilizada para guiar el debriefing.Item Predictors of relapse and treatment outcomes in biopsy-proven giant cell arteritis: a retrospective cohort study(Oxford University Press, 2016) Labarca, Cristian; Koster, Matthew; Crowson, Cynthia; Makol, Ashima; Ytterberg, Steven; Matteson, Eric; Warrington, KennethOBJECTIVE: To evaluate characteristics of relapse, relapse rates, treatment and outcomes among patients with biopsy-proven GCA in a large, single-institution cohort. METHODS: We conducted a retrospective review of all patients with biopsy-proven GCA from 1998 to 2013. Demographic, clinical, laboratory and treatment data at presentation and during follow-up were collected. Comparisons by relapse rate were performed using chi-square tests. Prednisone discontinuation by initial oral dose ≤40 and >40 mg/day was compared using Cox models. RESULTS: The cohort included 286 patients [74% female, mean age at diagnosis 75.0 years (s.d. 7.6), median follow-up 5.1 years). During follow-up, 73 patients did not relapse, 80 patients had one relapse and 133 had two or more relapses. The first relapse occurred during the first year in 50% of patients, by 2 years in 68% and by 5 years in 79%. More patients with established hypertension (P = 0.007) and diabetes (P = 0.039) at GCA diagnosis were in the high relapse rate group ( ≥ 0.5 relapses/year) and more females were in the low or high relapse groups than in the no relapse group (P = 0.034). Patients receiving an initial oral prednisone dose >40 mg/day were able to reach a dose of <5 mg/day [hazard ratio (HR) 1.46 (95% CI 1.09, 1.96)] and discontinue prednisone [HR 1.56 (95% CI 1.09, 2.23)] sooner than patients receiving ≤40 mg/day without an increase in observed glucocorticoid-associated adverse events. CONCLUSION: Females and patients with hypertension or diabetes at GCA diagnosis have more relapses during follow-up. Patients treated with an initial oral prednisone dose >40 mg/day achieved earlier prednisone discontinuation.