ORIGINAL ARTICLE Baseline characteristics of COVID-19 Italian patients admitted to Desio Hospital, Lombardy: a retrospective study Adela Sulejmani, Elisa Galimberti, Chiara Giacobone, Antonio Milano, Elena Scopetta, Jari Intra, Rosanna Falbo, Cecilia Sarto, Valerio Leoni and Paolo Brambilla Laboratory of Clinical Chemistry, Hospital of Desio and Monza, ASST-Monza and School of Medicine and Surgery, University of Milano- Bicocca, Milano, Italy ABSTRACT The correlation of clinical, radiological and laboratory findings of patients at admission in the Emergency Department (ED) with clinical severity and risk of mortality was investigated. Adult corona- virus disease 2019 (COVID-19) patients hospitalized in March 2020 in Desio Hospital, Lombardy, were retrospectively included in the study, and categorized in terms of disease severity and adverse out- come. Out of the 175 patients enrolled, 79% presented one or more comorbidities, with cardiovascular disease being the most frequent (62%). More than half of the patients showed lymphocytopenia and 20% thrombocytopenia. The patients in the severe group presented higher absolute neutrophil count (ANC), C-reactive protein (CRP), AST, LDH, procalcitonin (PCT) and BUN values compared to the non- severe group (p < .05). Increased odds of mortality associated with older age (OR ¼ 22.43; 95% CI 5.22–96.27), partial pressure of oxygen (PaO 2 )/fraction of inspired oxygen (FIO 2 ) ratio < 200 (OR ¼ 4.97; 95% CI 1.55–15.84), clinical severity (OR ¼ 21.32; 95% CI 2.27–200.13), creatinine > 106.08 mmol/L (OR ¼ 2.87; 95% CI 1.04–7.92) and creatine kinase > 2.90 mkat/L (OR ¼ 3.80; 95% CI 1.31–10.9) were observed on admission (p < .05). The above findings may contribute to identify early risk factors of poor prognosis, and to select the most appropriate management for patients. ARTICLE HISTORY Received 25 May 2020 Revised 19 September 2020 Accepted 1 November 2020 KEYWORDS COVID-19; lymphocytopenia; comorbidities; PaO 2 /FIO 2 ratio; older age; mortality Introduction The novel coronavirus Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) was first identified in December 2019 in Wuhan, Hubei Province of China and is responsible for coronavirus disease 2019 (COVID-19) [1–3]. The main routes of transmission are respiratory droplets and human-to-human contacts. A high proportion of infected subjects develops mild symptoms, such as fever, cough and asthenia. However, approximately 20% of the infected individuals presents serious illness, characterized by pneumonia, acute respiratory distress syndrome (ARDS), and in a few cases, multi-organ dysfunction syndrome (MODS) and death [1–3]. The current estimated crude mor- tality rate (number of reported deaths divided by reported cases) ranges from 3 to 4% [4]. In January 2020, the COVID-19 outbreak rapidly spread worldwide. On 20 February 2020, the first patient with COVID-19 was diagnosed in Italy, followed by several cases that were confirmed afterwards, especially in the Lombardy region, in northern Italy [5]. Up to 13 May 2020, a total of 221,133 people were positive for SARS-CoV-2, in particular 83,298 in Lombardy [6]. Severe and critical conditions were found in 16.9 and 2.04%, respectively, calculated out of a total 45,896 cases considered [6]. Italy has been one of the most hard-hit countries by COVID-19 and much still remains to be evaluated and understood. With this in mind, this study aims to assess the correlation of baseline characteristics of a group of Italian COVID-19 adult subjects with illness severity and outcomes. Materials and methods Study subjects and settings A retrospective study was conducted including 175 COVID- 19 adult patients admitted from 1 March 2020 to 31 March 2020 to Desio Hospital, a 344-bed facility located in Lombardy. Only SARS-CoV-2 cases confirmed through real- time reverse-transcriptase–polymerase-chain-reaction (RT–PCR) assays of nasopharyngeal swabs, in accordance with WHO guidance, were included in the analysis [7]. RT–PCR was performed at San Gerardo Hospital, Monza, and subsequently at the Italian National Institute Of Health. Only hospitalized Covid-19 patients with confirmed diagno- sis were enrolled in the study. Subjects who did not require hospitalization or were transferred to other hospitals were excluded from the study. The patients were categorized into two groups in terms of disease severity: non-severe (37 patients) and severe (138 CONTACT Jari Intra j.intra@asst-monza.it Laboratory of Clinical Chemistry, Hospital of Desio and Monza, ASST-Monza and School of Medicine and Surgery, University of Milano-Bicocca, Milano, Italy Supplemental data for this article can be accessed here. ß 2020 Medisinsk Fysiologisk Forenings Forlag (MFFF) SCANDINAVIAN JOURNAL OF CLINICAL AND LABORATORY INVESTIGATION 2021, VOL. 81, NO. 1, 18–23 https://doi.org/10.1080/00365513.2020.1846211