Many studies have reported hemocytometric changes in COVID-19 infection at admission and during the course of disease, but an overview is lacking. We provide a summary of the literature of hemocytometric changes and evaluate whether these changes may assist clinicians in diagnosing and predicting disease progression of COVID-19. Eighty-three out of 250 articles from December 2019 to 20 May 2020 were included from the databases, PubMed, Web of Science Core Collection, Embase, Cochrane and MedRxiv. Our review of the literature indicates that lymphopenia and an elevated neutrophil/lymphocyte ratio are the most consistent abnormal hemocytometric findings and that these alterations may augment in the course of time, especially in those with severe disease.

ObjectiveThe aim of this study was to explore the effects of cholecalciferol supplementation on vitamin D levels, bone mineral density (BMD), body fat distribution and insulin sensitivity in vitamin D-deficient HIV-1-infected patients. MethodsTwenty vitamin D-deficient HIV-1-infected patients were prospectively treated with 2000 IU cholecalciferol/day for 14 weeks, whereafter treatment was continued with half this dosage until 48 weeks. BMD, body fat distribution, 1,25-dihydroxy vitamin D 3 (1,25(OH) 2 D 3 ), fasting glucose, insulin, adiponectin, leptin, interleukin (IL)-6 and tumour necrosis factor (TNF)-a were measured at baseline, and at 24 and 48 weeks. Parathyroid hormone (PTH), 25-hydroxy vitamin D 3 [25(OH)D 3 ], cholesterol and triglycerides were measured at baseline, and at 12, 24 and 48 weeks. ResultsAfter 24 weeks, cholecalciferol supplementation significantly increased 25(OH)D 3 and 1,25(OH) 2 D 3 levels and decreased PTH and insulin sensitivity. After 48 weeks, however, only 25(OH)D 3 levels remained significantly different from baseline, while the other parameter levels returned to baseline, suggesting a dose-response effect. Cholecalciferol had no effect on BMD, adipokines and triglycerides. ConclusionsThe effect of cholecalciferol treatment in this cohort appears to be dose dependent. Cholecalciferol dosages of !2000 IU are necessary to achieve 1,25(OH) 2 D 3 levels that significantly decrease PTH, but also negatively affect insulin sensitivity. The results of this hypothesis-driven explorative study need to be confirmed in larger clinical trials.Keywords: bone mineral density, cholecalciferol supplementation, HIV/AIDS, insulin sensitivity, vitamin D deficiency Vitamin D is mainly known for its function in regulation of calcium homeostasis and maintenance of bone mineralization. Serum 25(OH)D 3 levels are the best indicator of vitamin D status [3]. The optimal 25(OH)D 3 level needed for maintenance of adequate bone mineral density (BMD) is unknown. A significant positive association between 25(OH)D 3 levels and BMD has been observed in both Another emerging problem associated with the widespread use of HAART is the lipodystrophy syndrome, which is characterized by altered fat distribution (central fat accumulation and peripheral fat loss) and metabolic alterations (dyslipidaemia, insulin resistance and diabetes mellitus). The vitamin D receptor (VDR) has also been found on adipocytes, suggesting a role for vitamin D in fat metabolism [7]. Indeed, it was demonstrated in vitro that 1,25-dihydroxy vitamin D 3 [1,25(OH) 2 D 3 ] inhibits adipocyte differentiation through, among other effects, inhibition of peroxisome proliferator-activated receptor-g (PPAR-g) [7][8][9]. However, 1,25(OH) 2 D 3 can elicit a nongenomic action on adipocytes in vitro, resulting in increased intracellular calcium levels and corresponding stimulation of adipogenesis and inhibition of lipolysis [10].A number of genetic polymorphisms in the VDR gene and low 25(OH)D 3 levels have been associated with insulin resistance and wi...