Hema Lec 1 (Chapter 1-2) - Blood Cells and Laboratory Testing

Erythrocytes

Red blood cells responsible for transporting oxygen and carbon dioxide.

Leukocytes

White blood cells that defend the body against infection.

Thrombocytes

Platelets, cells involved in clotting blood.

Anemia

Condition caused by low RBC count or low hemoglobin.

Polycythemia

Excessive RBC production, leading to thick blood.

Hemoglobin (Hgb)

Protein in RBCs that carries oxygen.

Hematocrit

The proportion of blood volume that is occupied by RBCs.

Reticulocytes

Immature RBCs, identified by their RNA content.

Neutrophils

A type of WBC that fights infections by engulfing pathogens.

Eosinophils

WBCs that combat parasites and allergens.

Basophils

WBCs with dark granules involved in allergic reactions and inflammation.

Basophilia

An elevated basophil count, often signaling a blood disease.

Lymphocytes

WBCs responsible for immune responses, including antibody production.

Lymphocytosis

Increased lymphocyte count, commonly due to viral infections.

Monocytes

Immature WBCs that turn into macrophages, which engulf foreign particles.

Macrophages

Immune cells that ingest and destroy pathogens and debris.

Platelets

Cells involved in blood clotting and maintaining vascular integrity.

Complete Blood Count (CBC)

A routine test that measures RBCs, WBCs, and platelets.

Coagulation

The process of blood clotting.

Flow cytometry

A lab method to analyze the characteristics of cells.

Osmotic fragility test

A diagnostic test for red blood cell fragility.

Erythrocyte Sedimentation Rate (ESR)

A test to detect inflammation.

Quality assurance

Ensures accurate and reliable lab results across all phases.

Quality control

Specific processes to confirm the validity and accuracy of lab tests.

Analytical Variables

Processes ensuring the quality of lab tests, including staff competence and validation.

Post-Analytical Variables

Procedures after testing, ensuring accuracy in reporting and interpretation of results.

Method Validation

Verifying a new test method for accuracy and precision.

Accuracy

How well the test result matches the true value.

Precision

The repeatability of the test results, measured using the coefficient of variation (CV).

Reference Interval

The range of values seen in a healthy population.

Levey-Jennings Chart

A visual tool to track quality control data over time.

Westgard Rules

Guidelines used to detect errors in laboratory results.

Delta Check

Comparing a patient's current and previous test results to detect significant changes.

External Quality Assessment (EQA)

Comparing lab results globally to ensure accuracy.

True Positive (TP)

A test result that correctly identifies the presence of disease.

False Positive (FP)

A test result that incorrectly indicates disease in a healthy individual.

True Negative (TN)

A test result that correctly identifies a person as disease-free.

False Negative (FN)

A test result that fails to detect disease in an affected individual.

Diagnostic Sensitivity

The ability of a test to correctly identify those with the disease.

Diagnostic Specificity

The ability of a test to correctly identify those without the disease.

Positive Predictive Value (PPV)

The likelihood that a positive test result accurately indicates the presence of disease.

Negative Predictive Value (NPV)

The likelihood that a negative test result accurately indicates the absence of disease.

Prevalence

The total number of cases of a disease in a population at a specific time.

Incidence

The rate of new cases of a disease in a population over a given time period.

Screening Test

A test used to detect disease in a large, often healthy population, focusing on high sensitivity.