Jurado, AuroraMartín, María CAbad-Molina, CristinaOrduña, AntonioMartínez, AlbaOcaña, EstherYarce, OscarNavas, Ana MTrujillo, AntonioFernández, LuisVergara, EstherRodríguez, BeatrizQuirant, BibianaMartínez-Cáceres, EvaHernández, ManuelPerurena-Prieto, JanireGil, JuanaCantenys, SergiGonzález-Martínez, GemaMartínez-Saavedra, María TRojo, RicardoMarco, Francisco MMora, SergioOntañón, JesúsLópez-Hoyos, MarcosOcejo-Vinyals, GonzaloMelero, JosefaAguilar, MartaAlmeida, DeliaMedina, SilviaVegas, María CJiménez, YeseniaPrada, ÁlvaroMonzón, DavidBoix, FranciscoCunill, VanesaMolina, Juan2021-04-092021-04-092020-08-14Jurado A, Martín MC, Abad-Molina C, Orduña A, Martínez A, Ocaña E, et al. COVID-19: age, Interleukin-6, C-reactive protein, and lymphocytes as key clues from a multicentre retrospective study. Immun Ageing. 2020 Aug 14;17:22.http://hdl.handle.net/10668/3280Background: The SARS-CoV-2 infection has widely spread to become the greatest public health challenge to date, the COVID-19 pandemic. Different fatality rates among countries are probably due to non-standardized records being carried out by local health authorities. The Spanish case-fatality rate is 11.22%, far higher than those reported in Asia or by other European countries. A multicentre retrospective study of demographic, clinical, laboratory and immunological features of 584 Spanish COVID-19 hospitalized patients and their outcomes was performed. The use of renin-angiotensin system blockers was also analysed as a risk factor. Results: In this study, 27.4% of cases presented a mild course, 42.1% a moderate one and for 30.5% of cases, the course was severe. Ages ranged from 18 to 98 (average 63). Almost 60 % (59.8%) of patients were male. Interleukin 6 was higher as severity increased. On the other hand, CD8 lymphocyte count was significantly lower as severity grew and subpopulations CD4, CD8, CD19, and NK showed concordant lowering trends. Severity-related natural killer percent descents were evidenced just within aged cases. A significant severity-related decrease of CD4 lymphocytes was found in males. The use of angiotensin-converting enzyme inhibitors was associated with a better prognosis. The angiotensin II receptor blocker use was associated with a more severe course. Conclusions: Age and age-related comorbidities, such as dyslipidaemia, hypertension or diabetes, determined more frequent severe forms of the disease in this study than in previous literature cohorts. Our cases are older than those so far reported and the clinical course of the disease is found to be impaired by age. Immunosenescence might be therefore a suitable explanation for the hampering of immune system effectors. The adaptive immunity would become exhausted and a strong but ineffective and almost deleterious innate response would account for COVID-19 severity. Angiotensin-converting enzyme inhibitors used by hypertensive patients have a protective effect in regards to COVID-19 severity in our series. Conversely, patients on angiotensin II receptor blockers showed a severer disease.enSevere acute respiratory syndrome coronavirus 2COVID-19ImmunosenescenceImmunityRenin-angiotensin systemACE2Interleukin-6C-reactive proteinLymphocytesSpainBetacoronavirusInmunosenescenciaInmunidadSistema renina-angiotensinaInterleucina-6Proteína C-ReactivaLinfocitosAngiotensin converting enzyme 2Medical Subject Headings::Phenomena and Processes::Immune System Phenomena::ImmunityMedical Subject Headings::Phenomena and Processes::Metabolic Phenomena::Metabolism::Renin-Angiotensin SystemMedical Subject Headings::Chemicals and Drugs::Amino Acids, Peptides, and Proteins::Proteins::Intercellular Signaling Peptides and Proteins::Cytokines::Interleukins::Interleukin-6Medical Subject Headings::Chemicals and Drugs::Amino Acids, Peptides, and Proteins::Proteins::Blood Proteins::Immunoproteins::C-Reactive ProteinMedical Subject Headings::Anatomy::Hemic and Immune Systems::Blood::Blood Cells::LeukocytesMedical Subject Headings::Organisms::Eukaryota::Animals::Chordata::Vertebrates::Mammals::Primates::Haplorhini::Catarrhini::Hominidae::HumansMedical Subject Headings::Diseases::Virus Diseases::RNA Virus Infections::Nidovirales Infections::Coronaviridae Infections::Coronavirus InfectionsMedical Subject Headings::Health Care::Health Care Quality, Access, and Evaluation::Quality of Health Care::Epidemiologic Factors::ComorbidityMedical Subject Headings::Check Tags::MaleMedical Subject Headings::Check Tags::FemaleMedical Subject Headings::Geographical Locations::Geographic Locations::Europe::Spainresearch article32802142open access10.1186/s12979-020-00194-w1742-4933PMC7426672