IntroductionHematological parameters are critical in disease diagnosis, management, and monitoring; however, complete blood count (CBC) reference intervals vary across populations. The aim of the current study was to provide the reference ranges of hematological parameters/indices in the healthy adult Saudi population.MethodsA multicenter retrospective cross-sectional study was conducted with a sample of employees who were screened pre-employment from January 2015 to December 2019, at tertiary care hospitals in three regions. Demographic and CBC data were extracted from the electronic health system. The 2.5th and 97.5th percentiles were used to determine the reference intervals.ResultsOf a total of 1,388 participants, 53.82% were male. The majority 96% was less than 40 years old, and 85% were from the Central region. Gender-related differences were observed for the RBC count, Hb, HCT, MCV, MCH, MCHC, and the platelet count. Age-related differences were observed for the RBC, Hb, HCT, and eosinophils. The WBC parameters did not differ by gender or age categories. Region-related differences were observed for the RBC, hemoglobin, HCT, MCV, WBC, and basophils. The platelet count was higher in the female group, the age group 40 years and above, and in the Western region. The prevalence of anemia was high in the female group and the Eastern region. The overall neutropenia rate was 12.8%.ConclusionThe data from this study provide hematological parameter reference ranges for the adult Saudi population by gender, age, and region. Gender and age-related differences were observed for the hematological parameters. Anemia was more frequent in the female group and the Eastern region. Caution must be taken when comparing or interpreting results from different age groups, gender, region of origin, and ethnicity.

We present the largest to date of a case series of nine patients with hematological and oncological malignancies who were infected with Middle East Respiratory Syndrome Coronavirus (MERS-CoV). MERS-CoV is a novel beta-coronavirus with a high fatality rate in comorbid patients. The majority of MERS cases globally were reported from Saudi Arabia (1983 cases, including 745 related deaths with a case-fatality rate of 37.5%) according to the WHO update of February 2019. All were clinically stable before acquiring the virus. Most of the cases had an active disease as relapse or refractory with three cases being neutropenic. The clinical presentation and radiological features of the patients were variable and inconsistent (Table 1). Diagnosis was confirmed with RT-PCR assays targeting upstream of the E gene and the open-reading frame gene 1a which had to be done repeatedly and required an average of 3 (with max. of 7) samples for a test to be positive (Table 2). All the patients developed respiratory failure, were admitted to the critical care unit (ICU) and required mechanical ventilation. The length of hospital stay ranged from 15 - 48, with an average of 24 days. Unfortunately, all nine patients died within days after admission to the ICU. In addition, the time from diagnosis to death has an average of 9 days ranging from 2-24 days, respectively. In conclusion, MERS CoV infection in hematology/oncology patients has a very poor prognosis regardless of the status of the underlying disease. The clinical presentation is not distinctive and confirming the diagnosis requires numerous respiratory samples. Measures to prevent nosocomial outbreaks should include proper compliance with personal protection equipment by health-care workers when managing patients with suspected and confirmed MERS-CoV infection and prompt isolation of infected patients. Future research is required to enhance our understanding of the disease and to evaluate superior diagnostic and therapeutic options. Disclosures No relevant conflicts of interest to declare.