RESUMEN
The Primary Immune Deficiency Treatment Consortium (PIDTC) is enrolling children with severe combined immunodeficiency (SCID) to a prospective natural history study. We analyzed patients treated with allogeneic hematopoietic cell transplantation (HCT) from 2010 to 2014, including 68 patients with typical SCID and 32 with leaky SCID, Omenn syndrome, or reticular dysgenesis. Most (59%) patients were diagnosed by newborn screening or family history. The 2-year overall survival was 90%, but was 95% for those who were infection-free at HCT vs 81% for those with active infection (P = .009). Other factors, including the diagnosis of typical vs leaky SCID/Omenn syndrome, diagnosis via family history or newborn screening, use of preparative chemotherapy, or the type of donor used, did not impact survival. Although 1-year post-HCT median CD4 counts and freedom from IV immunoglobulin were improved after the use of preparative chemotherapy, other immunologic reconstitution parameters were not affected, and the potential for late sequelae in extremely young infants requires additional evaluation. After a T-cell-replete graft, landmark analysis at day +100 post-HCT revealed that CD3 < 300 cells/µL, CD8 < 50 cells/µL, CD45RA < 10%, or a restricted Vß T-cell receptor repertoire (<13 of 24 families) were associated with the need for a second HCT or death. In the modern era, active infection continues to pose the greatest threat to survival for SCID patients. Although newborn screening has been effective in diagnosing SCID patients early in life, there is an urgent need to identify validated approaches through prospective trials to ensure that patients proceed to HCT infection free. The trial was registered at www.clinicaltrials.gov as #NCT01186913.
Asunto(s)
Trasplante de Células Madre Hematopoyéticas/métodos , Reconstitución Inmune , Inmunodeficiencia Combinada Grave/terapia , Preescolar , Femenino , Genotipo , Enfermedad Injerto contra Huésped/tratamiento farmacológico , Enfermedad Injerto contra Huésped/etiología , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Humanos , Reconstitución Inmune/genética , Lactante , Recién Nacido , Infecciones/etiología , Masculino , Tamizaje Neonatal , Estudios Prospectivos , Factores de Riesgo , Inmunodeficiencia Combinada Grave/complicaciones , Inmunodeficiencia Combinada Grave/mortalidad , Análisis de Supervivencia , Donantes de TejidosRESUMEN
Classical hypothesis testing focuses on testing whether treatments have differential effects on outcome. However, sometimes clinicians may be more interested in determining whether treatments are equivalent or whether one has noninferior outcomes. We review the hypotheses for these noninferiority and equivalence research questions, consider power and sample size issues, and discuss how to perform such a test for both binary and survival outcomes. The methods are illustrated on 2 recent studies in hematopoietic cell transplantation.