Background: Laboratory errors arise at any stage of testing. Detecting these inaccuracies before results are revealed might delay diagnosis and treatment, causing patient distress. Here, we studied the preanalytical errors in a hematology laboratory. Methods: This one-year retrospective analysis was conducted at the laboratory of a tertiary care hospital and included information on blood samples that were taken for hematology tests from both outpatients and inpatients. Laboratory records included sample collection and rejection information. The type and frequency of preanalytical errors were expressed as a proportion of total errors and sample number. Microsoft Excel was utilized to enter data. The results were presented in the form of frequency tables. Results: This research included 67,892 hematology samples. For preanalytical errors, 886 samples (1.3%) were discarded. The most common preanalytical error was insufficient sample (54.17%), and the least common was an empty/damaged tube (0.4%). Erroneous samples in the emergency department were mostly insufficient and clotted, whereas pediatric sample errors were caused by insufficient and diluted samples. Conclusion: Inadequate samples and clotted samples account for the vast majority of preanalytical factors. Insufficiency and dilutional errors were most frequent from pediatric patients. Adherence to best laboratory practices can drastically cut down on preanalytical errors.

The COVID-19 pandemic is rapidly spreading, and health care systems are being overwhelmed with the huge number of cases, with a good number of cases requiring intensive care. It has become imperative to develop safe and effective treatment strategies to improve survival. In this regard, understanding the pathogenesis of COVID-19 is highly important. Many hypotheses have been proposed, including the ACE/angiotensin-II/angiotensin receptor 1 pathway, the complement pathway, and the angiotensin-converting enzyme 2/mitochondrial assembly receptor (ACE2/MasR) pathway. SARS-CoV-2 binds to the ACE2 on the cell surface, downregulating the ACE2, and thus impairs the inactivation of bradykinin and des-Arg9-bradykinin. Bradykinin, a linear nonapeptide, is extensively distributed in plasma and different tissues. Kininogens in plasma and tissue are the main sources of the two vasoactive peptides called bradykinin and kallidin. However, the role of the dysregulated bradykinin pathway is less explored in the pathogenesis of COVID-19. Understanding the pathogenesis of COVID-19 is crucial for the development of new effective treatment approaches which interfere with these pathways. In this review, we have tried to explore the interaction between SARS-CoV-2, ACE2, bradykinin, and its metabolite des-Arg9-bradykinin in the pathogenesis of COVID-19.

Background. Anemia is a major health problem in Saudi Arabia and has multiple etiologies. Many studies have been conducted in Saudi Arabia in specific population groups like school children, adolescents, university students, and females in the reproductive age group, and most have reported high prevalence of anemia. This study was conducted in a specialist hospital in Makkah city and includes all outpatients aged 15years and above. Objective. To study the burden of anemia among hospital attendees, its stratification based on gender and age, and its severity along with the morphological types of anemia. Methods. This is a study conducted at a specialist hospital in Makkah city and one-month data were collected retrospectively from the laboratory database and include demographic and routine hematological results of complete blood count (CBC). Results. A total of 21,524 patients were included, out of which 9444 (43.9) were males and 12020 (56.1) were females. The overall prevalence of anemia was 38.7 (8339). Prevalence was very high in females, accounting for 68.2 (5689), whereas it was 31.8 (2650) in males. There were 39.6 (3301), 43.9 (3657), and 16.6 (1381) cases of mild, moderate, and severe anemia, respectively. In females, anemia was more prevalent in the age group of 15 to 49, which is considered as the reproductive age group. Microcytic anemia was the most prevalent type observed in this age group, accounting for 40.7 of all anemia cases. Normocytic anemia was more prevalent in the males, accounting for 52. Conclusion. Our study showed high prevalence of anemia among the patients attending outpatient departments in a specialist hospital. Females have high prevalence of anemia when compared to male population. Microcytic anemia was the most common anemia type among females and was seen in the 1549 age group. There is an increase in prevalence of anemia with age for males, whereas, in females, increased prevalence is observed in the reproductive age groups and the anemia prevalence maintained a steady decrease towards the 5th to the 9th decades. Normocytic anemia was more prevalent in the 5th to the 9th decades, indicating that there are more etiologies other than iron deficiency in the causation of anemia. Macrocytic anemia was the least reported anemia type. Anemia of mild and moderate severity was predominant in both genders, although severe anemia showed higher prevalence in females as compared to males. Conclusion. Anemia is highly prevalent in adolescents, adults, and the elderly in Makkah region. The most common cause is thought to be iron deficiency, although other causes are not uncommon. The authorities need to address the problem of prevention and reduction in anemia prevalence by taking effective measures and interventions.

Melatonin (MLT) is crucial in controlling human sleep-wake patterns. While it has long been recognized for regulating circadian rhythms, its demonstrated efficacy in managing various diseases has recently gained considerable attention. This review discusses MLT’s potential preventative and therapeutic effects on various diseases. Several studies have focused on examining the molecular mechanisms through which MLT brings about its protective or therapeutic effects on various diseases, including cancer, obesity, coronavirus, and cardiovascular diseases. Numerous preventative and therapeutic applications of MLT have been proposed, resulting from its ability to function as an antioxidant, anti-cancer, anti-inflammatory, and immune-regulating agent. There is a need for further research to determine MLT’s long-term effects on antioxidant defense systems, its preventative and therapeutic benefits, and its molecular basis.

Weight loss is a significant health problem among patients with head and neck cancer (HNC) that is attributable primarily to the tumor or tumor therapy. Critical weight loss (CWL) is defined as the unintentional loss of ≥5% of weight. Therefore, this study’s goal was to investigate and determine the possible factors influencing CWL among patients with HNC who have received radiotherapy or concurrent chemoradiotherapy (CCRT). We conducted a retrospective analysis of 175 patients who received radiotherapy or CCRT as either their primary, adjuvant, or combined treatment at the Oncology Center in King Abdullah Medical City. All patients were ≥18 years of age and diagnosed with HNC with no metastasis. The study results showed that 107 patients (61%) had CWL, while 68 (39%) did not. The following factors were significantly predictive of CWL with a multivariate regression analysis: pretreatment BMI (AOR = 1.1, 95% CI = 1.02–1.17), oral cavity cancer (AOR = 10.36, 95% CI = 1.13–94.55), and male sex (AOR = 3.15, 95% CI = 1.39–7.11). In conclusion, weight loss is highly prevalent among HNC patients during treatment. Accordingly, pretreatment BMI, cancer in the oral cavity, and being male can be considered predictive factors for CWL.

Background/Objectives: The CD4⁺ T-cell count is a primary indicator of immune status in HIV-positive patients. Rapid identification of immune suppression severity may improve clinical decision-making and triage. The relationship between CD4⁺ counts and other immunologic and hematologic markers, however, is not well characterized, especially in resource-limited settings. The objectives of this study were to classify HIV-positive patients by CD4⁺ T-cell count, compare hematologic and immunologic markers across severity groups, assess correlations between CD4⁺ and other variables, and evaluate routine blood tests’ potential to serve as surrogate indicators of immune status. Methods: A retrospective cohort of 229 HIV-positive patients from the Regional Laboratory in Makkah, Saudi Arabia, was stratified into three groups: severe (500 cells/mm³). Hematologic (RBC, Hb, Hct, ESR, WBC, and lymphocytes) and immunologic (CD3, CD4, CD8, B, NK cells, and CD4/CD8 ratio) data were analyzed using ANOVA and Pearson correlation. Results: Significant group differences were observed in RBC, Hb, Hct, ESR, and lymphocyte counts (p < 0.001). CD4⁺ counts correlated positively with CD3 (r = 0.76), B cells (r = 0.63), and CD8⁺ (r = 0.41) and negatively with ESR (r = –0.37). Over 75% of the patients had disrupted CD4/CD8 ratios, and one-third of the severely immunosuppressed patients showed abnormal B- and NK-cell counts. Conclusions: Routine hematologic markers reflect immune suppression severity and can serve as accessible, low-cost tools for monitoring HIV-positive patients in resource-limited settings. Integrating these parameters into immune monitoring may enhance early assessment and provide regional benchmarks for clinical evaluation.