hematology

hematology is the doctrine of blood and its functions. The branch of medicine refers to the physiology and pathology of the blood. Hematology is of great importance in routine diagnostics, in monitoring the progress of a wide variety of diseases, but also in basic research. More than 90 percent of all medical diagnoses are based on haematological findings.

What is the hematology?

Hematology is a combined word of Greek origin from the two syllables Haima, the blood, and Logos, the teaching. Consequently, hematology literally means the doctrine of blood. In clinical use, the main focus is on the pathology of the blood. The composition of the blood is changed in characteristic ways in a wide variety of diseases, so that hematological values ​​allow direct conclusions to be drawn about faulty body functions.

Basically, the science of hematology consists of what is called numerical hematology and cell hematology. Numerical hematology deals primarily with the normal values ​​and the circulating blood cells that deviate from these normal values.

Cell hematology as a sub-area comprises the analysis of cell structures of blood cells or cells of the bone marrow. The most important cell hematological method is the so-called differential blood count of the white blood cells, leukocytes. Another branch of hematology is hemato-oncology, which deals specifically with malignant neoplasms in the blood or bone marrow.

The best-known haematological, malignant disease is leukemia, around 500 different forms of leukemia are known to date. While some of these have an extremely good prognosis and a good chance of recovery for the patient, other forms, such as acute lymphoblastic leukemia, usually lead to death within a few weeks of the diagnosis.

Treatments & therapies

The simplest hematological examination is the creation of a small blood count, consisting of the number of leukocytes, erythrocytes, platelets and hemoglobin. It is a general examination in the family doctor's practice or as an initial examination when you are admitted to a hospital. Normal values ​​can rule out many diseases. However, if the blood count values ​​are significantly changed, these pathological findings must always be further clarified by differential diagnosis.

The most important normal hematological values ​​are white blood cells 4000-9000, erythrocytes 4.5-5.5 million, platelets 180,000-300,000, hematocrit 38-41% and hemoglobin 12-17g. All information relates to 1 cubic millimeter of whole blood. Hemoglobin is the blood pigment in red blood cells, or erythrocytes. During the gas exchange in the lungs, hemoglobin has the ability to bind oxygen to itself and thus to supply all body cells with vital oxygen through the bloodstream. If there is a lack of hemoglobin due to an illness or an accident, the hemoglobin level can be raised again by giving blood, so-called red cell concentrates.

However, this is usually unsuccessful if the cause of the drop in hemoglobin is internal bleeding, for example in the gastrointestinal tract. The hematocrit value indicates the percentage by volume of all cellular components in the total blood. With the exception of the differential blood count, all numerical-hematological parameters are now determined with fully automatic machines in medical laboratories. However, a manual, microscopic examination of the colored blood smear is required for the differential blood count.

The main concern here is the splitting of the white blood cells into the individual leukocyte fractions. Important leukocyte fractions are neutrophils, basophils, eosinophils, and small and large lymphocytes. They all occur physiologically in flowing blood. Bone marrow cells, such as plasma cells, myelocytes, metamyelocytes or promyelocytes, do not normally appear in the blood. If these can be seen in the differential blood count, one speaks of a left shift, which is always to be regarded as pathological.

The most common causes of a left shift are inflammatory changes and infections. This kind of left shift is reactive, i.e. reversible, and disappears through therapy. In leukemia, on the other hand, the shift to the left is irreversible, so the pathological bone marrow cells appear permanently in the bloodstream.

Diagnosis & examination methods

All hematological examination methods are part of laboratory medicine. The blood is hematologically examined in the medical laboratory by specially trained specialists, the medical-technical-laboratory assistants, MTLA. To do this, the venous blood taken must be made incoagulable. An anticoagulant, EDTA, is therefore contained in the blood tubes for haematological examinations. The technical and medical validation and approval of the haematological findings is always the responsibility of a specialist in laboratory medicine.

Special semiautomatic or fully automatic machines are used for cell hematology, which can hematologically analyze a large number of blood samples under the supervision of laboratory staff within a very short time. The hematological diagnosis appears simple at first, but then it is quite complex when it comes to assigning pathological findings to a patient's complaints. In the case of a large number of hematological diseases, interdisciplinary cooperation between laboratory medicine, pathology, cytology and radiology is required.

In the treatment of haemato-oncological diseases, the hematology values ​​are primarily used to monitor the progress, because the parameters allow essential conclusions to be drawn about the course and prognosis of haematological diseases. Hematological diseases are very complex and complex. The most important hematological symptoms include leukemia, lymphoma, the various types of anemia, hemoglobin formation disorders and so-called storage diseases such as hemochromatosis.

The prognosis of haematological diseases is particularly dependent on genetic factors. In detail, these genetic factors cannot be influenced to this day. Hematology has made considerable progress in recent years, but the range of research is far from being exhausted. The changes in this branch of laboratory medicine therefore have the potential to fundamentally change medicine in patients in the future, thanks to basic research.