de la Hera, BelénUrcelay, ElenaBrassat, DavidChan, AndrewVidal-Jordana, AngelaSalmen, AnkeVillar, Luisa MariaAlvarez-Cermeño, José CarlosIzquierdo, GuillermoFernández, OscarOliver, BegoñaSaiz, AlbertAra, Jose RamónVigo, Ana GArroyo, RafaelMeca, VirginiaMalhotra, SunnyFissolo, NicolásHorga, AlejandroMontalban, XavierComabella, Manuel2016-04-152016-04-152014-12-11de la Hera B, Urcelay E, Brassat D, Chan A, Vidal-Jordana A, Salmen A, et al. Natalizumab-related anaphylactoid reactions in MS patients are associated with HLA class II alleles. Neurol Neuroimmunol Neuroinflamm. 2014; 1(4):e47http://hdl.handle.net/10668/2175Journal Article;OBJECTIVES We aimed to investigate potential associations between human leukocyte antigen (HLA) class I and class II alleles and the development of anaphylactic/anaphylactoid reactions in patients with multiple sclerosis (MS) treated with natalizumab. METHODS HLA class I and II genotyping was performed in patients with MS who experienced anaphylactic/anaphylactoid reactions and in patients who did not develop infusion-related allergic reactions following natalizumab administration. RESULTS A total of 119 patients with MS from 3 different cohorts were included in the study: 54 with natalizumab-related anaphylactic/anaphylactoid reactions and 65 without allergic reactions. HLA-DRB1*13 and HLA-DRB1*14 alleles were significantly increased in patients who developed anaphylactic/anaphylactoid reactions (p M-H = 3 × 10(-7); odds ratio [OR]M-H = 8.96, 95% confidence interval [CI] = 3.40-23.64), with a positive predictive value (PPV) of 82%. In contrast, the HLA-DRB1*15 allele was significantly more represented in patients who did not develop anaphylactic/anaphylactoid reactions to natalizumab (p M-H = 6 × 10(-4); ORM-H = 0.2, 95% CI = 0.08-0.50), with a PPV of 81%. CONCLUSIONS HLA-DRB1 genotyping before natalizumab treatment may help neurologists to identify patients with MS at risk for developing serious systemic hypersensitivity reactions associated with natalizumab administration.enAlelosAnticuerpos monoclonales humanizadosAntígenos de histocompatibilidad clase IPrueba de histocompatibilidadEsclerosis múltipleMedical Subject Headings::Phenomena and Processes::Genetic Phenomena::Genetic Structures::Genome::Genome Components::Genes::AllelesMedical Subject Headings::Chemicals and Drugs::Amino Acids, Peptides, and Proteins::Proteins::Blood Proteins::Immunoproteins::Immunoglobulins::Antibodies::Antibodies, Monoclonal::Antibodies, Monoclonal, HumanizedMedical Subject Headings::Phenomena and Processes::Genetic Phenomena::GenotypeMedical Subject Headings::Analytical, Diagnostic and Therapeutic Techniques and Equipment::Diagnosis::Diagnostic Techniques and Procedures::Clinical Laboratory Techniques::Immunologic Tests::Histocompatibility TestingMedical Subject Headings::Organisms::Eukaryota::Animals::Chordata::Vertebrates::Mammals::Primates::Haplorhini::Catarrhini::Hominidae::HumansMedical Subject Headings::Diseases::Respiratory Tract Diseases::Respiratory HypersensitivityMedical Subject Headings::Diseases::Nervous System Diseases::Autoimmune Diseases of the Nervous System::Demyelinating Autoimmune Diseases, CNS::Multiple SclerosisMedical Subject Headings::Analytical, Diagnostic and Therapeutic Techniques and Equipment::Investigative Techniques::Epidemiologic Methods::Statistics as Topic::Probability::Odds RatioMedical Subject Headings::Analytical, Diagnostic and Therapeutic Techniques and Equipment::Investigative Techniques::Epidemiologic Methods::Statistics as Topic::Confidence IntervalsMedical Subject Headings::Chemicals and Drugs::Amino Acids, Peptides, and Proteins::Proteins::Glycoproteins::Membrane Glycoproteins::Histocompatibility Antigens Class Iresearch article25520955open access10.1212/NXI.00000000000000472332-7812PMC4268037