Blood in the smear after a gynecological examination can be normal, but it can indicate a serious pathology. It is necessary to distinguish between conditions in which blood in a smear can be a dangerous symptom. To do this, you need to consider all possible options and reasons for this problem.
Morphological features of a blood smear
Most women after the examination at the gynecologist receive usual results of smears, but many do not know what to do with the results when they return abnormal. However, abnormal results usually do not indicate a serious pathology. Knowing the causes of an abnormal smear and protecting against the risk factors associated with this result can lower your chances of a serious uterine pathology.
The causes of the appearance of blood in the smear depend on which cells are found in this smear mainly. After all, the blood consists of different cells, and each performs its function. Accordingly, the detection of predominantly one or another cell indicates a certain pathology.
Leukocytes in the blood smear are the most important cells that protect the human body. All leukocytes have nuclei that distinguish them from others. There are five types of leukocytes. They fall into two main classes: granulocytes (including neutrophils, eosinophils and basophils) and agranulocytes (including lymphocytes and monocytes). This classification depends on whether granules can be isolated in their cytoplasm using a light microscope and conventional staining techniques. All leukocytes are able to move like an amoeba and can migrate from blood vessels to surrounding tissues.
The level of leukocytes is often an indicator of the disease, and, therefore, their calculation is an important indicator of blood. The normal level of leukocytes in the smear of peripheral blood is usually from 4,000 to 10,000 leukocytes per microliter of blood. They make up about 1% of the total blood volume in a healthy adult, which makes them significantly less numerous than red blood cells by 40-45%. This is normal when it is part of a healthy immune response that occurs frequently. This is sometimes abnormal when it is neoplastic or autoimmune in origin. A decrease below the lower limit is called leukopenia. This indicates a weakened immune system.
Leukocytes in a gynecological smear can also be in a small amount, but their number should not exceed 10 cells. If their number is larger, one can think of inflammatory changes in the cervix or uterus.
Platelets in the blood smear are a component of the blood, the function of which (along with the factors of blood coagulation) is to stop bleeding by starting blood clotting in blood vessels. Platelets do not have a cell nucleus: they are fragments of the cytoplasm, which are obtained from the megakaryocytes of the bone marrow, which then enter the bloodstream. These non-activated platelets are biconvex discoid (lenticular) structures, 2-3 μm in the largest diameter. On a stained blood smear, platelets appear as dark purple spots, about 20% of the erythrocyte diameter. A smear is used to examine platelets for size, shape, quality number and lumps. The ratio of platelets to erythrocytes in healthy adults ranges from 1:10 to 1:20.
The main function of platelets is to promote hemostasis: the process of stopping bleeding at the site of the interrupted endothelium. They gather in place and, if the interruption of the vessel is physically too large, they lock the hole. First, platelets attach to substances outside the interrupted endothelium: adhesion. Secondly, they change shape, include receptors and secrete chemical messengers: activation. Thirdly, they are connected to each other through receptor bridges: aggregation. The formation of this platelet plug (primary hemostasis) is associated with activation of the coagulation cascade with the resultant precipitation of fibrin and binding (secondary hemostasis). The end result is a clot.
A low concentration of platelets is thrombocytopenia and is caused either by a decrease in production, or by an increase in fracture. An increased concentration of platelets is a thrombocytosis and either congenital or due to unregulated production.
The concentration of platelets is measured either manually using a hemocytometer, or by placing blood in an automated platelet analyzer. The normal range of these cells in the peripheral blood is 150-400 thousand per microliter.
Erythrocytes in the blood smear are the most common type of blood cells and the main means for delivering oxygen to the body tissues through the circulatory system. The erythrocyte cytoplasm is rich in hemoglobin, an iron-containing biomolecule that can bind oxygen and is responsible for the red color of cells. The cell membrane consists of proteins and lipids, and this structure provides the properties necessary for the physiological function of cells, such as stability in circulating the circulatory system and, in particular, the capillary network.
In humans mature erythrocytes are flexible and oval biconvex disks. They do not have a cell nucleus and most organelles to accommodate the maximum space for hemoglobin; they can be considered as bags with hemoglobin. Approximately 2.4 million new red blood cells are produced per second in adults. Cells develop in the bone marrow and circulate for about 100-120 days in the body before their components are recycled by macrophages. Each treatment takes about 60 seconds (one minute). About a quarter of the cells in the human body are red blood cells.
When red blood cells undergo stress in narrowed vessels, they release ATP, which causes the vessel walls to relax and expand to promote normal blood flow. When hemoglobin molecules are deoxygenated, erythrocytes release S-nitrosothiols, which also act to dilate the blood vessels, thereby directing more blood to the area of the body depleted of oxygen.
Erythrocytes can also synthesize nitric oxide enzymatically, using L-arginine as a substrate, like endothelial cells. The effect of red blood cells on physiological levels of shear stress activates nitric oxide synthase and the export of nitric oxide, which can contribute to the regulation of vascular tone.
Erythrocytes also play a role in the immune response of the body: when lysing with pathogens such as bacteria, their hemoglobin releases free radicals that destroy the cell wall and the pathogen membrane, killing it.
Women have about 4-5 million erythrocytes per microliter (cubic millimeter).
Reticulocytes in the blood smear are immature erythrocytes, usually amounting to about 1% of erythrocytes in the human body. In the process of erythropoiesis (formation of erythrocytes) reticulocytes develop, and then circulate about a day in the bloodstream, and then develop into mature red blood cells. They are called reticulocytes because of the reticular network of ribosomal RNA, which becomes visible under a microscope with certain spots. Reticulocytes appear slightly more blue than other red blood cells. The normal proportion of reticulocytes in the blood depends on the clinical situation, but usually ranges from 0.5% to 2.5%. This percentage is in the normal range with a normal level of red blood cells; for example, if someone is anemic, but has a percentage of reticulocytes as low as 1%, the bone marrow probably does not produce new blood cells at a rate that will correct anemia.
The amount of reticulocytes is a good indicator of bone marrow activity, as it is a recent production and allows you to determine the number of reticulocytes and the index of production of reticulocytes. These values can be used to determine if the production problem affects anemia, and can also be used to monitor the progression of anemia treatment.
Mononuclear cells in a blood smear are any cell of peripheral blood that has a round nucleus. These cells consist of lymphocytes (T cells, B cells, NK cells) and monocytes. Mononuclear cells are the largest type of leukocytes and can differentiate into macrophages and myeloid lines of dendritic cells. In humans, lymphocytes form the majority of the mononuclear population, followed by monocytes and only a small percentage of dendritic cells. Monocytes are produced by the bone marrow from precursors, called monoblast, bipotent cells, which differentiate from hematopoietic stem cells. Monocytes circulate in the bloodstream for about one to three days, and then usually move to tissues throughout the body, where they differentiate into macrophages and dendritic cells. They make up three to eight percent of the white blood cells in the blood. About half of the body's monocytes are stored as a reserve in the spleen. Monocytes that migrate from the blood to other tissues will then differentiate into resident tissue macrophages or dendritic cells. Macrophages are responsible for protecting tissues from foreign matter, but are also suspected of the importance of forming important organs such as the heart and the brain. These are cells that have a large smooth nucleus, a large cytoplasmic area, and many internal vesicles for processing foreign matter.
Mononuclear cells perform three basic functions of the immune system. This is phagocytosis, antigen presentation and production of cytokines. Phagocytosis is the process of absorbing microbes and particles with subsequent splitting and destruction of this material. Monocytes can perform phagocytosis using intermediate (opsonizing) proteins, such as antibodies or complement, that cover the pathogen, and also by binding to the microbe directly through the pattern recognition receptors that recognize the pathogens. Monocytes are also capable of killing infected cells through antibody-dependent cell-mediated cytotoxicity.
Eosinophils in the blood smear are one of the components of the immune system responsible for combating multicellular parasites and certain infections. These cells are eosinophilic or "acid-loving" because of their large acidophilic cytoplasmic granules, which show their affinity for acids. Inside the cells there are small granules that contain many chemical mediators, such as eosinophilic peroxidase, ribonuclease (RNase), deoxyribonuclease (DNase), lipase. These mediators are released by a process called degranulation after eosinophil activation, and are toxic to parasite tissues.
Eosinophils account for about 1-3% of white blood cells. Eosinophils persist in the circulation for 8-12 hours and can survive in the tissue for another 8-12 days in the absence of stimulation.
There are also eosinophils that play a role in the fight against viral infections, which is evident due to the abundance of RNase that they contain within their granules, and when fibrin is removed during inflammation. Eosinophils, along with basophils and mast cells, are important mediators of allergic reactions and the pathogenesis of asthma and are associated with the severity of the disease.