Abnormal Laboratory Test Research Articles

A case of incidental infantile gallbladder adenomyomatosis: an unusual US finding of uncertain clinical significance.

Adenomyomatosis of the gallbladder is defined as hypertrophy of the gallbladder mucosal epithelium that invaginates into a thickened muscularis propria, leading to the formation of intramural diverticula. It is typically considered a benign condition most commonly affecting adults and, rarely, children. In this case report, we present a case of gallbladder adenomyomatosis in a 3-month-old infant. The diagnosis was made incidentally on ultrasound examination of the abdomen, in an otherwise asymptomatic child with no laboratory test abnormalities and no underlying disease. The purpose of this case report is to make infantile adenomyomatosis and its implications known to clinicians, as the literature on this topic is limited. To the best of our knowledge, this is the youngest reported case of adenomyomatosis in the pediatric population.

Diagnosis and treatment of coagulopathy secondary to single fetal demise in twin pregnancy

Introduction: Disseminated intravascular coagulation following single fetal demise in a twin pregnancy is a rare event. As such, the diagnosis and management of such cases are complicated and require the assistance of various laboratory tests. Case: 26 years old patient, carrying dichorionic diamniotic twin pregnancy was complicated by single fetal demise at 21+6 weeks and preterm premature rupture of membranes (PPROM) at 24+5 weeks. Pregnancy was managed conservatively until 30+4 weeks gestation when abnormal laboratory tests including dysfibrinogenemia and pathological thromboelastogram (TEG) indicated the development of disseminated intravascular coagulopathy (DIC) while the patient remained asymptomatic. A multidisciplinary team decided on prompt delivery by cesarean section. Cesarean delivery (CD) was uneventful, yet post-operative course was complicated by worsening laboratory tests and post-partum hemorrhage that were treated by uterotonics and blood products resulting in clinical and laboratory normalization. Conclusion: DIC following single fetal demise in a twin pregnancy is rare. A new laboratory test, TEG, may aid in diagnosis and management of DIC. Keywords: Twins, Disseminated intravascular coagulation (DIC), Intrauterine fetal demise (IUFD), Thromboelastogram (TEG), Coagulopathy.

A Phase I, Randomized, Double-Blind, Placebo-Controlled, Single Ascending Dose, Multiple Ascending Dose and Food Effect Study to Evaluate the Tolerance, Pharmacokinetics of Jaktinib, a New Selective Janus Kinase Inhibitor in Healthy Chinese Volunteers.

Background: Jaktinib is a novel selective janus kinase 1/2 inhibitor. The phase I first-in-human study evaluated the tolerance and pharmacokinetics of jaktinib in healthy Chinese subjects. Methods: A randomized, double-blind, placebo-controlled study were designed. A total of 126 healthy subjects were enrolled into the single ascending dose, multiple ascending dose and food effect study. Safety endpoints included adverse events, abnormal vital signs, 12-lead ECGs, abdominal ultrasound, chest x-ray, physical examination and clinical laboratory tests. Blood, urine and feces samples were collected at predetermined time points for pharmacokinetic analysis of jaktinib, the metabolites ZG0244 and ZG0245, which are formed by oxidation or hydrolysis metabolic pathway, respectively. Results: Jaktinib was absorbed with a median time to peak plasma concentration of 1.25–3.5 h and was eliminated with a half-life of 2.952–9.040 h. Linear pharmacokinetic characteristic was presented over the dose range from 25 to 400 mg. No obvious accumulation was observed after multiple doses for 10 days. Administration after a high-fat breakfast significantly increased the absorption of jaktinib. The accumulated fraction of jaktinib and the determined metabolites excreted in urine and feces was 19.478%. Jaktinib was well tolerated in all single dose cohorts. In multiple dose cohorts, 200 mg q24 h method was evaluated as maximally tolerated dose. Neutropenia, diarrhea, dizziness and headache were the most frequently reported treatment related adverse events. No deaths, serious or Grade ≥4 adverse events was developed. Conclusion: Jaktinib was well tolerated when single dose ranging from 25 to 400 mg and multiple dose up to 200 mg q24 h. The safety and pharmacokinetic characteristics support the next trial in myelofibrosis patients.

Chronic alcoholic liver disease in the practice of the medical assistant

Alcohol abuse and the resulting alcoholic liver disease (ALD) are the leading cause of disease and death worldwide. The absence of symptoms of the disease at the early stages explains the diagnosis at the late stages. Better identification of life history and prognostic factors, as well as the search for reliable non-invasive techniques for detecting ALD, are required. The main therapy for patients with ALD, regardless of the stage of the disease, is long-term alcohol abstinence. In compensated patients, the end results are the normalization of abnormal laboratory tests and reduction of liver fibrosis. These end results can be controlled non-invasively, but modern medical interventions are largely limited and ineffective. Maintenance therapy is the basis of treatment, in which it is worth paying special attention to herbal preparations as less toxic.

Dose adjustment for tyrosine kinase inhibitors in non‑small cell lung cancer patients with hepatic or renal function impairment (Review).

In recent years, a number of tyrosine kinase inhibitors (TKIs) have been approved for the treatment of non-small cell lung cancer. These novel treatments exhibit improved efficacy and toxicity when compared to conventional chemotherapy agents. TKIs are administered orally, which has the advantages of improved flexibility and convenience for the patients. However, challenges have arisen in the use of these novel agents. Prescribing drugs for patients with hepatic or renal function impairment poses a challenge for clinicians due to the large pharmacokinetic variability in each individual patient. Moreover, several TKIs have been shown to cause laboratory test abnormalities normally associated with hepatic or renal injury. The aim of the present review was to discuss the effects of hepatic and renal function impairment on the pharmacokinetic variability of 17 TKIs and their potential hepatotoxicity and nephrotoxicity, and to recommend dose adjustment for patients with hepatic or renal impairment.

Diagnosis of von Willebrand disease in Western Mexico.

Von Willebrand disease (VWD) is the most common inherited bleeding disorder with a prevalence of 0.1%, characterised by quantitative or functional deficiency of von Willebrand factor (VWF). VWD diagnosis is based on symptomology, biochemical and genetic tests, but limited laboratory resources and VWD heterogeneity still generate an important subdiagnosis gap worldwide and in our country. To identify the type and subtype of VWD in a cohort of patients with a history of excessive bleeding in Western Mexico. This prospective cohort study from 2012 to 2019 included patients with mucocutaneous bleeding or abnormal laboratory tests. A standardised questionnaire and confirmatory tests were applied: FVIII:C, VWF activity, VWF antigen, and VWF multimeric analysis. Of the 297 patients recruited, 207 (69.7%) were excluded because their values exceeded 50% in VWF activity and VWF antigen. Of those 90 remaining, 54 (18.2%) had low VWF, and only 36 patients (12.1%) were diagnosed with VWD. Among them, 17 (47.2%) had quantitative deficiencies, of whom 14 were assigned as type 1 and 3 as type 3.The remaining 19 cases were diagnosed as type 2 (52.8%): type 2A and 2B were the most frequent with 6 and 7 cases respectively; 4 cases were possible type 2M and two suggestive of 2N, however, this was not confirmed. This study highlights the challenges of VWD diagnosis using a comprehensive panel of diagnostic tests which should extend to supplemental tests of VWF:CB, VWF:FVIIIB, and sequencing the VWD gene to confirm the results from the panel assays.

The necessity of routine postoperative laboratory tests after total hip arthroplasty for hip fracture in a semi-urgent clinical setting

BackgroundRecent studies suggest that routine postoperative laboratory tests are not necessary after primary elective total hip arthroplasty (THA). This study aims to evaluate the utility of routine postoperative laboratory tests in patients undergoing THA for hip fracture in a semi-urgent clinical setting.Materials and methodsThis retrospective study included 213 consecutive patients who underwent primary unilateral THA for hip fractures. Patient demographics, clinical information, and laboratory tests were obtained from the electronic medical record system. Multivariate logistic regression analysis was performed to identify risk factors associated with abnormal laboratory test-related interventions.ResultsA total of 207 patients (97.18%) had abnormal postoperative laboratory results, which were mainly due to anemia (190/213, 89.20%) and hypoalbuminemia (154/213, 72.30%). Overall, 54 patients (25.35%) underwent a clinical intervention, 18 patients received blood transfusion, and 42 patients received albumin supplementation. Factors associated with blood transfusion were long operative time and low preoperative hemoglobin levels. Factors associated with albumin supplementation were long operative time and low preoperative albumin levels. Of the 33 patients with abnormal postoperative creatinine levels, 7 patients underwent a clinical intervention. For electrolyte abnormalities, sodium supplementation was not given for hyponatremia, three patients received potassium supplementation, and one patient received calcium supplementation.ConclusionsThis study demonstrated a high incidence of abnormal postoperative laboratory tests and a significant clinical intervention rate in patients who underwent THA for hip fracture in a semi-urgent clinical setting, which indicates that routine laboratory tests after THA for hip fracture are still necessary for patients with certain risk factors.Level of EvidenceLevel III.Trial registration Clinical trial registry number ChiCTR1900020690.

The Association of Laboratory Test Abnormalities With Mortality Risk in Pediatric Intensive Care.

To determine the bivariable associations between abnormalities of 28 common laboratory tests and hospital mortality and determine how mortality risks changes when the ranges are evaluated in the context of commonly used laboratory test panels. A 2009-2016 cohort from the Health Facts (Cerner Corporation, Kansas City, MO) database. Hospitals caring for children in ICUs. Children cared for in ICUs with laboratory data. None. There were 2,987,515 laboratory measurements in 71,563 children. The distribution of laboratory test values in 10 groups defined by population percentiles demonstrated the midrange of tests was within the normal range except for those measured predominantly when significant abnormalities are suspected. Logistic regression analysis at the patient level combined the population-based groups into ranges with nonoverlapping mortality odds ratios. The most deviant test ranges associated with increased mortality risk (mortality odds ratios > 5.0) included variables associated with acidosis, coagulation abnormalities and blood loss, immune function, liver function, nutritional status, and the basic metabolic profile. The test ranges most associated with survival included normal values for chloride, pH, and bicarbonate/total Co2. When the significant test ranges from bivariable analyses were combined in commonly used test panels, they generally remained significant but were reduced as risk was distributed among the tests. The relative importance of laboratory test ranges vary widely, with some ranges strongly associated with mortality and others strongly associated with survival. When evaluated in the context of test panels rather than isolated tests, the mortality odds ratios for the test ranges decreased but generally remained significant as risk was distributed among the components of the test panels. These data are useful to develop critical values for children in ICUs, to identify risk factors previously underappreciated, for education and training, and for future risk score development.

Laboratory monitoring during antifungal treatment of paediatric tinea capitis.

Griseofulvin and terbinafine are considered effective first-line therapies for tinea capitis (TC). Haematological dyscrasias and hepatic injury are possible adverse effects with both drugs. There is a debate in the literature regarding the necessity of laboratory monitoring during griseofulvin and terbinafine treatment. We aimed at assessing the prevalence and severity of haematological and hepatic laboratory test abnormalities in a paediatric cohort of African immigrants in Tel-Aviv with TC who were treated with Terbinafine or Griseofulvin. We conducted a retrospective study of all TC cases diagnosed and treated at the paediatric dermatology clinic, Tel-Aviv Medical centre, between June 2013 and March 2019. Epidemiologic, clinical and laboratory data were collected. Our cohort included 321 patients of whom 225 (70%) were treated with Griseofulvin and 96 (30%) with Terbinafine. We identified a total of 64 (20%) patients with haematological or hepatic laboratory test abnormalities that in most cases (96.3%) were considered as mild. No difference in laboratory abnormalities prevalence was identified between the griseofulvin and terbinafine groups (21.3% and 16.6%, respectively). Only one patient treated with Griseofulvin revealed significantly increased levels of hepatic aminotransferases that required discontinuation of treatment. Mild elevation in hepatic transaminases is relatively common among paediatric patients treated with systemic antifungal treatment for TC. However, significant laboratory abnormalities are extremely rare and may be diagnosed and addressed early through periodic laboratory tests monitoring.

Combined herbal medicine for chronic alcoholic liver disease

Alcohol abuse with resultant alcoholic liver disease (ALD) are a leading cause of morbidity and mortality worldwide. Due to absence of clinical symptoms of the disease in the early stages, it is diagnosed in the later stages with higher complications and mortality rates. Diagnosis of ALD requires a better determination of life history and prognostic factors, as well as the search for reliable non-invasive techniques. Early detection of alcoholic steatohepatitis in primary care settings and subsequent interventions will facilitate the satisfaction of this requirement. Despite some important advances in understanding the pathogenesis and clinical features of ALD, the past 40 years have not seen significant advances in the therapy. The long-term alcohol abstinence is the main therapy for ALB patients, regardless of the disease stage. It is associated with improved clinical outcomes across the ALD spectrum: from asymptomatic early cases to complicated severe cases. Clinical ultimate outcomes depend on the ALD stage. The ultimate outcomes are associated with normalisation of abnormal laboratory test results and reduction in liver fibrosis in compensated patients. These ultimate outcomes can be monitored using non-invasive tools, but current medical interventions are largely limited and ineffective. Supportive therapy forms the basis of the treatment, it is worth paying special attention to combined herbal medicines as less toxic ones with single contraindications and consistent with the desire of many patients to use natural preparations.

Predictors at Admission of Mechanical Ventilation and Death in an Observational Cohort of Adults Hospitalized With Coronavirus Disease 2019.

BackgroundCoronavirus disease (COVID-19) can cause severe illness and death. Predictors of poor outcome collected on hospital admission may inform clinical and public health decisions.MethodsWe conducted a retrospective observational cohort investigation of 297 adults admitted to eight academic and community hospitals in Georgia, United States, during March 2020. Using standardized medical record abstraction, we collected data on predictors including admission demographics, underlying medical conditions, outpatient antihypertensive medications, recorded symptoms, vital signs, radiographic findings, and laboratory values. We used random forest models to calculate adjusted odds ratios (aORs) and 95% confidence intervals (CI) for predictors of invasive mechanical ventilation (IMV) and death.ResultsCompared with age <45 years, ages 65–74 years and ≥75 years were predictors of IMV (aOR 3.12, CI 1.47–6.60; aOR 2.79, CI 1.23–6.33) and the strongest predictors for death (aOR 12.92, CI 3.26–51.25; aOR 18.06, CI 4.43–73.63). Comorbidities associated with death (aORs from 2.4 to 3.8, p <0.05) included end-stage renal disease, coronary artery disease, and neurologic disorders, but not pulmonary disease, immunocompromise, or hypertension. Pre-hospital use vs. non-use of angiotensin receptor blockers (aOR 2.02, CI 1.03–3.96) and dihydropyridine calcium channel blockers (aOR 1.91, CI 1.03–3.55) were associated with death.ConclusionsAfter adjustment for patient and clinical characteristics, older age was the strongest predictor of death, exceeding comorbidities, abnormal vital signs, and laboratory test abnormalities. That coronary artery disease, but not chronic lung disease, was associated with death among hospitalized patients warrants further investigation, as do associations between certain antihypertensive medications and death.

Follow-Up on the Abnormal Laboratory Test Results with Automatic Interpretation.

Failing to follow up on the abnormal test results can cause serious health problems to patients. We conducted a retrospective medical record review of 3200 randomly selected patients aged 18 to 76 in 14 state clinics and two private laboratory services querying the common regional patient registry. One patient could be included (1 clinical case) in the study only once. We invited patients to take part in the interviews to gain a deeper understanding of the motives to follow up or not after receiving a recommendation and explanation of the role of the automatically generated interpretation in this decision. A qualitative study of the patients' motivation was performed with a group of 689 patients. All the patients who received their interpretations showed a much higher follow-up rate (68% average) than the patients who did not receive interpretations (49 % average). The results of our research demonstrated that there is a significant impact on the patients' decision to follow up on the tests. Patients consider time factor as an important advantage of the computer interpretations and are willing to get automatic interpretations if they can receive it faster than the ones from their doctor (question 4: median =3 out of 7). Discussing the reasons behind the decision to follow up, the patients do trust the computerized clinical decision support systems (question 5: median = 5 out of 7), however, they prefer to receive interpretations and recommendations from doctors (question 3: median = 7).

A rare case of Raoultella planticola urinary tract infection. A case report with literature review

Urine infections represent 40-50% of all infections in hospitalized patients. The most common uropathogens are E.coli, S.saprophitycus, and less commonly Enterobacteriaceae, such as Proteus mirabilis and Klebsiella pneumoniae. The spectrum of microorganisms isolated in hospital conditions may be wider. Raoultella planticola is a rare cause of human infections, so far only few cases of ZUM with this etiology have been described.A 56-years-old patient, with a history of cardiac disease, with exacerbation of chronic kidney disease, was admitted to the Department of Internal Medicine. The reason for admission was general deterioration. Many abnormalities in laboratory tests were detected. The doctors' attention was focused on the significant bacteriuria. Moreover, the patient reported dysuria symptoms. Material for urine microbiological culture was taken and empirical antibiotic therapy with ciprofloxacin started. The obtained result of urine culture allowed to identify the bacteria by R. planticola. As a result of the applied treatment, the patient's condition improved.An increasing number of infections with R. planticolla etiology is observed. The bacterium may lead to infections in many systems. The group of patients at risk of the disease includes people with renal dysfunction, who are immunosuppressed. Infections of R. planticolla etiology are usually characterized by good antibiotic response and positive prognosis.

Safety and tolerability of therapeutic plasma exchange in autoimmune neurological diseases - a retrospective single-centre analysis.

The sudden onset of autoimmune neurological diseases often threatens life. In such clinical situations, fast, effective and safe treatment is needed. Therapeutic plasma exchange (TPE) is an option in the treatment of autoimmune disorders. The aim was to assess the tolerability and safety of membrane-based therapeutic plasma exchange (mTPE) in patients with autoimmune neurological diseases. A total of 410 TPE treatments were performed in 91 adult patients. The main reasons for performing TPE were: Guillain-Barre syndrome (39.56%), chronic inflammatory demyelinating polyradiculoneuropathy (20.88%), and myasthenia gravis (17.58%). A total of 183 (44.6%) mTPE treatments were performed without complications. In 18 (19.8%) patients, there were no complications observed in any of the mTPE procedures (a total of 83 procedures). Serious and life-threatening complications occurred during four (0.97%) mTPEs. The most common abnormality in laboratory tests was hypocalcaemia. In patients with a fibrinogen c oncentration ≥ 2 .63 g /L, m easured before the second plasmapheresis, coagulation in the TPE filter was more f requently o bserved (p = 0 .04). Our study proves that the use of plasmapheresis conducted by filtration in the treatment of autoimmune neurological diseases is safe and well tolerated.

Intraoperative coagulopathy during cesarean section as an unsuspected initial presentation of COVID-19: a case report

BackgroundThe world’s understanding of COVID-19 continues to evolve as the scientific community discovers unique presentations of this disease. This case report depicts an unexpected intraoperative coagulopathy during a cesarean section in an otherwise asymptomatic patient who was later found to have COVID-19. This case suggests that there may be a higher risk for intrapartum bleeding in the pregnant, largely asymptomatic COVID-positive patient with more abnormal COVID laboratory values.CaseThe case patient displayed D-Dimer elevations beyond what is typically observed among this hospital’s COVID-positive peripartum population and displayed significantly more oozing than expected intraoperatively, despite normal prothrombin time, international normalized ratio, fibrinogen, and platelets.ConclusionThere is little published evidence on the association between D-Dimer and coagulopathy among the pregnant population infected with SARS-CoV-2. This case report contributes to the growing body of evidence on the effects of COVID-19 in pregnancy. A clinical picture concerning for intraoperative coagulopathy may be associated with SARS-CoV-2 infection during cesarean sections, and abnormal COVID laboratory tests, particularly D-Dimer, may help identify the patients in which this presentation occurs.

Analysis of Clinical Pathway for Patients With Cleft Lip and Palate.

To evaluate the implementation of a clinical pathway (CP) and identify clinical factors affecting the CP for cleft lip and palate (CLP) patients. A specific CP for CLP patients was developed at CLP Medical Center of Stomatological Hospital affiliated to Nanjing Medical University in 2008. The authors reviewed the collected data of 1810 consecutive patients using the CP for repairing cleft lip, cleft palatal, and alveolar cleft. The patients were treated between January 2008 and December 2019. The rate of completion and risk factors affecting dropout from the CP were analyzed. The completion rates of the CP in cleft lip, cleft palate and alveolar cleft patients were 68.3% (n = 345), 82.4% (n = 785) and 76.1% (n = 268), respectively. The overall completion rate was 77.2% (n = 1398). The main reasons for dropping out were pre-operation events (n = 212, 11.7%) and post-operation events (n = 188, 10.4%). Among the factors of dropout of CP, laboratory test abnormalities accounted for the majority of pre- and post-operation events (n = 179, 9.9%). In statistical analysis, the combined abnormities and events associated with operations were significant risk factors affecting the dropout rate from CP. The use of CP for CLP patients was reliable but the completion rate was relatively low because of perioperative events. These results provided some evidence of risk factors which should be considered when modifying the protocol of CP for CLP patients in order to achieve higher completion rate.

Multi-Organ Infarction in a Patient Receiving Infliximab

A 54 year-old woman with a history of psoriatic arthritis on methotrexate and infliximab was admitted to a local hospital with fevers and abdominal pain. She underwent cholecystectomy, but was readmitted to our institution 9 days later with persistent symptoms. The patient had a three pack-year smoking history. On arrival, the patient was in moderate discomfort. BP was elevated at 158/80 mm Hg. Examination revealed an early systolic murmur at the left upper sternal border, 2+ nonpitting edema at the ankles, and a psoriatic rash. The abdomen was diffusely tender to palpation, without costovertebral angle tenderness. Abnormal laboratory test results included leukocyte count of 26,300 cells/ μ l, hemoglobin of 10.4 g/dl, and C-reactive protein of 230.7 mg/L. Viral hepatitis screening was negative. Computed tomography scan of the abdomen and pelvis demonstrated a wedge-shaped focus in the splenic hilum, mild diffuse small bowel dilation, and striated enhancement of …

Predictors of COVID-19 severity: A literature review.

The coronavirus disease 2019 (COVID-19) pandemic is a rapidly evolving global emergency that continues to strain healthcare systems. Emerging research describes a plethora of patient factors-including demographic, clinical, immunologic, hematological, biochemical, and radiographic findings-that may be of utility to clinicians to predict COVID-19 severity and mortality. We present a synthesis of the current literature pertaining to factors predictive of COVID-19 clinical course and outcomes. Findings associated with increased disease severity and/or mortality include age > 55 years, multiple pre-existing comorbidities, hypoxia, specific computed tomography findings indicative of extensive lung involvement, diverse laboratory test abnormalities, and biomarkers of end-organ dysfunction. Hypothesis-driven research is critical to identify the key evidence-based prognostic factors that will inform the design of intervention studies to improve the outcomes of patients with COVID-19 and to appropriately allocate scarce resources.

Use of diffusion-weighted imaging in the noninvasive diagnostic of obstructed biliary ducts.

This study sought to evaluate the role of diffusion-weighted imaging (DWI) in differentiation between obstructed and unobstructed bile ducts in patients undergoing magnetic resonance imaging (MRI). Eighty-four patients, 40 males and 44 females (mean age: 56.4 ± 15.1years), undergoing MRI with DWI (0-50-500-700) were evaluated and divided into two groups: 58 with abnormal laboratory tests (obstructed group) and 26 with normal laboratory values (unobstructed group). Laboratory tests were total bilirubin, alkaline phosphatase, and gamma-glutamyltransferase. Median ADC values were calculated and correlated with laboratory tests and degree of bile-duct dilatation (absent, moderate, or severe). The persistence of signal on DWI (b500 and b700) in the biliary tract was evaluated. Bilirubin values were tested for correlation with bile-duct ADC values and persistence of b700 signal. For statistical analysis, Student t test, chi-square test and Wilcoxon-Mann-Whitney test were used. ADC maps were plotted for three levels of the biliary tree, and a receiver operating characteristic (ROC) curve was calculated. In the obstructed group, 15 patients had severe dilatation, 24 had moderate dilatation, and 19 had no appreciable dilatation; 38 patients had persistent signal on b700 images. In the unobstructed group, 23 patients had no dilatation and 3 had moderate dilatation; 4 patients had persistent signal on b700 images. Correlation was found between degree of bile-duct dilatation, bilirubin levels, persistence of b700 signal, and ADC map values. The calculated ADC map cutoff value (353 10-6 mm2/s) was able to differentiate the obstructed and unobstructed groups with 92.3% sensitivity, 81% specificity, and 91.9% accuracy. DWI is able to distinguish patients with obstructed versus unobstructed bile ducts, regardless of the degree of dilatation, correlating with clinical and laboratory findings.

COVID-19: Review and hematologic impact

In the last decades, coronaviruses have been a major threat to public health worldwide. SARS-CoV-2 is the third known coronavirus that causes fatal respiratory diseases in humans. The initial clinical features of SARS-CoV-2 infection are quite nonspecific and not all suspected patients can be tested to exclude or confirm the diagnosis. Increasing scientific evidence has shown that abnormalities in routine laboratory tests, particularly hematological tests, have the potential to indicate, in a quick, practical and economical way, the need for specific laboratory tests for the diagnosis of SARS-CoV-2 infection, besides assisting in the prognosis of the disease and in the optimization of its clinical monitoring. In order to address in a simple and practical way the various aspects related to SARS-CoV-2 infection, this review reports the history of the virus, the epidemiology and pathophysiology of COVID-19, with emphasis on its laboratory diagnosis, particularly in hematological changes found during the course of the disease.