RT Journal Article T1 A prospective study on the natural history of patients with profound combined immunodeficiency: An interim analysis A1 Carsten Speckmann, A1 Allende Martínez, Luis Miguel A1 González Granado, Luis Ignacio A1 Stephan Ehl, AB Background: Absent T-cell immunity resulting in life-threatening infections provides a clear rationale for hematopoetic stem cell transplantation (HSCT) in patients with severe combined immunodeficiency (SCID). Combined immunodeficiencies (CIDs) and "atypical" SCID show reduced, not absent T-cell immunity. If associated with infections or autoimmunity, they represent profound combined immunodeficiency (P-CID), for which outcome data are insufficient for unambiguous early transplant decisions.Objectives: We sought to compare natural histories of severity-matched patients with/without subsequent transplantation and to determine whether immunologic and/or clinical parameters may be predictive for outcome.Methods: In this prospective and retrospective observational study, we recruited nontransplanted patients with P-CID aged 1 to 16 years to compare natural histories of severity-matched patients with/without subsequent transplantation and to determine whether immunologic and/or clinical parameters may be predictive for outcome.Results: A total of 51 patients were recruited (median age, 9.6 years). Thirteen of 51 had a genetic diagnosis of "atypical" SCID and 14 of 51 of CID. About half of the patients had less than 10% naive T cells, reduced/absent T-cell proliferation, and at least 1 significant clinical event/year, demonstrating their profound immunodeficiency. Nineteen patients (37%) underwent transplantation within 1 year of enrolment, and 5 of 51 patients died. Analysis of the HSCT decisions revealed the anticipated heterogeneity, favoring an ongoing prospective matched-pair analysis of patients with similar disease severity with or without transplantation. Importantly, so far neither the genetic diagnosis nor basic measurements of T-cell immunity were good predictors of disease evolution.Conclusions: The P-CID study for the first time characterizes a group of patients with nontypical SCID T-cell deficiencies from a therapeutic perspective. Because genetic and basic T-cell parameters provide limited guidance, prospective data from this study will be a helpful resource for guiding the difficult HSCT decisions in patients with P-CID. PB Science Direct SN 0091-6749 YR 2017 FD 2017-04-13 LK https://hdl.handle.net/20.500.14352/114408 UL https://hdl.handle.net/20.500.14352/114408 LA eng NO Speckmann C, Doerken S, Aiuti A, Albert MH, Al-Herz W, Allende LM, Scarselli A, Avcin T, Perez-Becker R, Cancrini C, Cant A, Di Cesare S, Finocchi A, Fischer A, Gaspar HB, Ghosh S, Gennery A, Gilmour K, González-Granado LI, Martinez-Gallo M, Hambleton S, Hauck F, Hoenig M, Moshous D, Neven B, Niehues T, Notarangelo L, Picard C, Rieber N, Schulz A, Schwarz K, Seidel MG, Soler-Palacin P, Stepensky P, Strahm B, Vraetz T, Warnatz K, Winterhalter C, Worth A, Fuchs S, Uhlmann A, Ehl S; P-CID study of the Inborn Errors Working Party of the EBMT. A prospective study on the natural history of patients with profound combined immunodeficiency: An interim analysis. J Allergy Clin Immunol. 2017 Apr;139(4):1302-1310.e4. doi: 10.1016/j.jaci.2016.07.040. Epub 2016 Sep 19. PMID: 27658761; PMCID: PMC6311415. DS Docta Complutense RD 29 abr 2025