Major blood disorders in children

In children, especially at an early age, the most common blood disease is anemia. Anemia is understood as a decrease in the amount of hemoglobin (less than 110 g / l), or the number of erythrocytes (less than 4x 10 ¹² / l), or both. Depending on the degree of decrease in hemoglobin content, mild (Hb 90-110 g / l), moderate (Hb 60-80 g / l) and severe (Hb less than 60 g / l) forms of anemia are distinguished.

Anemia in children is clinically manifested by varying degrees of pallor of the skin and visible mucous membranes. In acute anemia (posthemorrhagic), patients complain of dizziness, tinnitus, systolic murmur over the heart, and a "whirring top" murmur on the vessels. Iron deficiency anemia is most often observed in children of the first three years, and posthemorrhagic anemia, developing after severe or latent bleeding (especially gastrointestinal, renal and uterine), is most often observed in school-age children. In patients suffering from anemia, it is important to know the regenerative capacity of the bone marrow. For this, the number of reticulocytes is determined. Reticulocytosis always indicates sufficient regenerative function of the bone marrow. At the same time, the absence of reticulocytes in the peripheral blood or their very low levels (not corresponding to the degree of anemia) can be one of the signs of hypoplasia (hypoplastic anemia).

In anemia, as a rule, erythrocytes of irregular shape (poikilocytosis) and different sizes (anisocytosis) are found. Hemolytic anemias occupy a special place. They can be congenital or acquired. Clinically, hemolysis is often accompanied by an increase in body temperature, pallor and varying degrees of jaundice, an enlarged liver and spleen. In Minkowski-Chauffard hemolytic anemia, microspherocytosis is observed. In acquired hemolytic anemias, the size of erythrocytes is usually unchanged.

Hemolysis syndrome is often observed in erythrocytopathies, which are based on a decrease in the activity of enzymes in erythrocytes, and in hemoglobinopathies, which are characterized by a congenital disorder in the structure of the globin portion of hemoglobin.

A special place is occupied by hemolytic disease of the newborn, caused by antigenic incompatibility of fetal and maternal erythrocytes. This incompatibility can be by the Rh factor (RI) or by the ABO system. The first form is more severe. In these cases, fetal erythrocytes penetrate the mother's blood and cause the production of hemolysins. As the gestational age increases, maternal hemolysins are transplacentally transferred to the fetus and cause hemolysis, which is clinically manifested at birth by anemia, severe jaundice (up to nuclear), and enlarged liver and spleen. In particularly severe forms, the fetus may die (hydrops fetalis).

Leukocytosis and leukopenia in children

Changes in white blood may be expressed in an increase or decrease in the number of leukocytes. An increase in the number of leukocytes (in children, above 10x10 ⁹ /l) is called leukocytosis, a decrease (less than 5x10 ⁹ /l) is called leukopenia. It is important to know due to which formed elements of white blood an increase or decrease in the number of leukocytes occurs. A change in the number of leukocytes can most often occur due to neutrophils or lymphocytes. Less often, a change in the number of eosinophils and monocytes is observed. Neutrophilic leukocytosis - absolute neutrophilia - is characteristic of septic and purulent-inflammatory diseases (sepsis, pneumonia, purulent meningitis, osteomyelitis, appendicitis, purulent cholecystitis). Neutrophilia in purulent-septic diseases is accompanied by some rejuvenation - a shift in the leukocyte formula to the left to band and young, less often to myelocytes. Neutrophilia is less pronounced in diphtheria, scarlet fever. In malignant blood diseases in children - hemopathies (especially in leukemia) - an especially high leukocytosis can be observed, a characteristic feature of which is the presence of immature formed elements (lymphoblasts and myeloblasts) in the peripheral blood. In chronic leukemia, leukocytosis is especially high (several hundred thousand), and all transitional forms of leukocytes are present in the white blood formula. In acute leukemia, hiatus leicemicus is usually observed in the blood formula, when both especially immature cells and a small number of mature ones (segmented neutrophils) without transitional forms are present in the peripheral blood. Lymphocytic leukocytosis - absolute lymphocytosis - is characteristic of asymptomatic infectious lymphocytosis (sometimes above 100x10 ⁹ /l), whooping cough - (20...30)x 10 ⁹ /l, infectious mononucleosis. In the first two diseases, the lymphocytes are mature, while in infectious mononucleosis of an unusual form, they are broadly cytoplasmic. Lymphocytosis due to immature cells - lymphoblasts - is characteristic of lymphoid leukemia. Relative lymphocytosis is observed in viral infections (flu, acute respiratory viral infections, measles, rubella, etc.).

Eosinophilic leukemoid reactions in the form of an increase in the number of eosinophils in the peripheral blood are characteristic of allergic diseases (bronchial asthma, serum sickness), helminthiases (ascariasis, toxocariasis, etc.) and protozoan infections (giardiasis, etc.). Sometimes monocytic leukemoid reactions are observed, the nature of which is not always clear. Relative monocytosis is characteristic of measles rubella, malaria, leishmaniasis, diphtheria, Vincent-Simanovsky angina, epidemic parotitis, etc.

Leukopenia is most often observed due to a decrease in the neutrophil content - neutropenia. Neutropenia in children is considered to be a decrease in the absolute number of leukocytes (neutrophils) by 30% below the age norm. Neutropenia can be congenital and acquired. They often occur after taking medications (especially cytostatic - 6-mercaptopurine, cyclophosphamide, etc., used in the treatment of cancer patients, as well as sulfonamides, amidopyrine), during recovery from typhoid fever, brucellosis, during the rash with measles and rubella, malaria. Leukopenia is characteristic of viral infections, as well as a number of diseases that are characterized by a particularly severe course.

Neutropenia in combination with severe anemia is observed in hypoplastic anemia. Relative and absolute lymphopenia is observed in immunodeficiency states. It develops several months after the onset of clinical signs of immunodeficiency (mainly due to T-lymphocytes).

Hemorrhagic syndrome in children

The term "hemorrhagic syndrome" refers to increased bleeding in the form of bleeding from the mucous membranes of the nose, the appearance of hemorrhages in the skin and joints, gastrointestinal bleeding, etc. In clinical practice, it is advisable to distinguish several types of bleeding.

1. In the hematoma type, extensive hemorrhages are determined in the subcutaneous tissue, under the aponeuroses, in the serous membranes, in the muscles and joints with the development of deforming arthrosis, contractures, pathological fractures. Profuse post-traumatic and postoperative bleeding is observed, less often - spontaneous. The late nature of bleeding is expressed, i.e. several hours after the injury. The hematoma type is characteristic of hemophilia A and B (deficiency of factors VIII and IX).
2. The petechial-spotted, or microcirculatory, type is characterized by petechiae, ecchymoses on the skin and mucous membranes, spontaneous bleeding or bleeding that occurs with the slightest trauma - nasal, gingival, uterine, renal. Hematomas are rare, the musculoskeletal system is not affected. Postoperative bleeding, except for bleeding after tonsillectomy, is not observed. Hemorrhages in the brain are frequent and dangerous; as a rule, they are preceded by petechial hemorrhages in the skin and mucous membranes. The microcirculatory type is observed in thrombocytopenia and thrombocytopathy, in hypo- and dysfibrinogenemia, deficiency of factors X, V and II.
3. The mixed (microcirculatory-hematoma) type is characterized by a combination of the two previously listed forms and some features: the microcirculatory type predominates, the hematoma type is expressed insignificantly (hemorrhages mainly into the subcutaneous tissue). Hemorrhages into the joints are rare. This type of bleeding is observed in von Willebrand disease and von Willebrand-Jurgens syndrome, since the deficiency of coagulant activity of plasma factors (VIII, IX, VIII + V, VII, XIII) is combined with platelet dysfunction. Of the acquired forms, this type of bleeding can be caused by intravascular coagulation syndrome, an overdose of anticoagulants.
4. The vasculitic-purple type is caused by exudative-inflammatory phenomena in microvessels against the background of immunoallergic and infectious-toxic disorders. The most common disease of this group is hemorrhagic vasculitis (or Schonlein-Henoch syndrome). Hemorrhagic syndrome is represented by symmetrically located, mainly on the limbs in the area of large joints, elements, clearly demarcated from healthy skin. Elements of the rash protrude above its surface, are represented by papules, blisters, vesicles, which can be accompanied by necrosis and crust formation. A wave-like course, "blooming" of elements from crimson to yellow with subsequent fine peeling of the skin is possible. With the vasculitic-purple type, abdominal crises with profuse bleeding, vomiting, macro- and (more often) microhematuria are possible.
5. The angiomatous type is characteristic of various forms of telangiectasias. The most common type is Rendu-Osler disease. With this type of bleeding, there are no spontaneous and post-traumatic hemorrhages into the skin, subcutaneous tissue and other organs, but there are repeated bleedings from areas of angiomatously altered vessels - nasal, intestinal, less often - hematuria and pulmonary.

Clinical identification of these bleeding variants allows us to determine a set of laboratory tests necessary to clarify the diagnosis or cause of hemorrhagic syndrome.

Bone marrow failure

Myelophthisis may develop acutely when there is damage by some myelotoxic factors, such as a large dose of benzene or penetrating radiation. Sometimes such a reaction occurs in children due to individual high sensitivity to antibiotics (for example, chloramphenicol), sulfonamides, cytostatics, anti-inflammatory drugs or painkillers. In case of total damage of all bone marrow hematopoiesis sprouts, they speak of "panmyelophthisis" or total hematopoiesis aplasia. General clinical manifestations may include high fever, intoxication, hemorrhagic rashes or bleeding, necrotic inflammation and ulcerative processes on the mucous membranes, local or generalized manifestations of infections or mycoses. In the blood - pancytopenia in the absence of signs of blood regeneration, in the bone marrow puncture - depletion of cellular forms of all sprouts, a picture of cellular decay and devastation.

Much more often, hematopoietic insufficiency in children manifests itself as a slowly progressing disease, and its symptoms correspond to the most involved hematopoietic germ. In pediatric practice, patients with congenital constitutional forms of hematopoietic insufficiency may be encountered.

Constitutional aplastic anemia, or Fanconi anemia, is most typically diagnosed after 2-3 years, but sometimes in senior school age. The disease debuts with the development of monocytopenia or anemia, or leukopenia, or thrombocytopenia. In the first case, the reason for seeking medical attention is general weakness, pallor, shortness of breath, and heart pain. In the second case, persistent infections and lesions of the oral mucosa; in the third case, the debut is increased bleeding and "bruises" on the skin. Over the course of several weeks, sometimes months, and rarely longer, there is a natural transition to bicytopenia (two sprouts) and, finally, pancytopenia of the peripheral blood. Bone marrow failure in most patients is accompanied by multiple skeletal anomalies, and aplasia of one of the radial bones is especially typical. In fact, anemia in such pancytopenia is characterized by a clear tendency to increase the size of circulating erythrocytes (macrocytic anemia), often leukocytes. Cytogenetic research confirms the effect of increased "fragility" of chromosomes in lymphoid cells.

The most significant congenital diseases accompanied by monocytopenic syndrome in peripheral blood are presented below.

Erythroblastic aplasia:

• congenital hypoplastic anemia;
• Blackfan-Diamond;
• transient erythroblastopenia of childhood;
• transient aplasia in diseases with chronic hemolysis of erythrocytes.

Neutropenia:

• Kostmann's disease;
• Schwekman-Diamond syndrome;
• cyclic neutropenia.

Thrombocytopenia:

• thrombocytopenia in aplasia of the radius;
• amegakaryocytic thrombocytopenia.

Many blood diseases in children, as well as non-hematological diseases, manifest as cytopenic syndromes regardless of congenital bone marrow hematopoiesis deficiency. In these cases, either transient acquired low hematopoiesis productivity is observed, as happens, for example, with malnutrition, or relative hematopoiesis deficiency with a high rate of blood cell loss or destruction.

Low efficiency of erythropoiesis, clinically simulating hypoplastic anemia, may occur with insufficiency of natural physiological stimulators of erythropoiesis. These may include renal hypoplasia or chronic renal failure with loss of erythropoietin production.

Thyroid insufficiency is also often manifested by persistent anemia. Sometimes the cause of erythropoiesis inhibition can be seen in several factors of the pathogenesis of the underlying somatic disease, including nutritional disorders, the myelosuppressive effect of chronic inflammation, and frequent side effects of the drugs used.

Alimentary deficiency, or "nutritional", anemia

In countries or regions with widespread childhood starvation due to protein-energy deficiency, anemia is a natural companion of hunger and is always polyetiological in its genesis. Along with the factors of nutritional deficiency, numerous acute and chronic infections, helminthiases and parasitoses play a serious role in its origin. In countries with a somewhat more organized life and sanitary culture, alimentary anemia is most often detected in young children, where the limited range of food products does not provide the opportunity for a balanced supply of the entire complex of necessary nutrients. Iron supply is especially critical for children born prematurely or with low body weight. In case of premature birth, the child is deprived of the period of nutrient accumulation (deposition), which is related in terms to the last weeks of pregnancy. They do not have the necessary depots of fatty energy substances for a newborn, and, in particular, iron, copper and vitamin B12. Breast milk, especially in a poorly nourished nursing mother, cannot compensate for the lack of stored nutritional components. Iron deficiency poses a danger to oxygen supply both through a deficiency of blood hemoglobin and through disruptions in tissue mechanisms of oxygen transfer from blood to tissues. Hence the special vigilance of pediatricians observing young children regarding the provision of the child with adequate nutrition and the prevention of anemia. The introduction of whole cow's milk or its mixtures into the child's diet can also affect the provision of iron at the end of the 1-2nd year of life. Here, iron losses with erythrocytes often occur, entering the intestinal lumen through diapedesis. Finally, in adolescence, especially in girls who have begun to menstruate, there is again a high probability of iron deficiency and the development of anemia. Pediatric practice uses several laboratory approaches to identify the onset of iron deficiency, in particular through the determination of ferritin content, transferrin saturation with iron, etc. However, the first line of diagnosis is undoubtedly hematological studies aimed at relatively early detection of initial signs of anemia.

The list of nutrients, the deficiency of which naturally leads to anemia and sometimes leukopenia, can be quite wide. The combination of iron and copper deficiencies at an early age and in nutritional disorders in all age groups has already been noted. Cases of megaloblastic anemia in children with a deficiency of vitamin or folic acid, or thiamine, hypochromic anemia with a deficiency of vitamin B6, hemolytic anemia with a lack of vitamin E in underweight children have also been described.

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Hemoglobinopathies in children

They are quite common among ethnic groups originating from Africa, Asia, the Middle East, and the Mediterranean. Diseases of this group are caused by the carriage and genetic inheritance of abnormal globin structures in hemoglobin. The most common representatives of this group are sickle cell anemia and thalassemia (major and minor). Common manifestations of hemoglobinopathies are chronic anemia, spleno- and hepatomegaly, hemolytic crises, and multiple organ damage due to hemosiderosis or hemochromatosis. Intercurrent infections provoke crises of the underlying disease.

The key to recognition is a biochemical study of hemoglobin. Recognition is possible already in the first trimester of pregnancy based on trophoblast biopsy data.

Acute leukemia in children

Leukemia is the most common form of malignant neoplasms in children. The vast majority of acute leukemias originate from lymphoid tissue (85%). This is probably due to the exceptionally rapid growth rate of lymphoid formations in children, exceeding the growth rate of any other organs and tissues in the body. In addition to the most powerful growth stimulation through the growth hormone and insulin systems, lymphoid formations are additionally stimulated by numerous infections, immunizations, and injuries. It has been found that the "peak" of childhood leukemia occurs between the ages of 2 and 4, and the highest incidence of leukemia is observed in children with the best family, living environment, and nutrition. A peculiar exception are children with Down syndrome, who also have a high risk of developing leukemia.

The clinical picture of leukemia combines signs of displacement of normal hematopoiesis with anemia, thrombocytopenia and often hemorrhagic manifestations, hyperplastic changes in the hematopoietic organs - enlargement of the liver, spleen, lymph nodes, often gums, testicles in boys and any internal organs to which tumor proliferation extends. The main way in diagnostics is the statement of the proliferation of anaplastic hematopoietic cells in the myelogram or bone biopsy. For more than 20 years, acute lymphoblastic leukemia in children has ceased to be a fatal disease. The use of modern polychemotherapy regimens, sometimes in combination with bone marrow transplants, guarantees either long-term survival or a practical cure for the disease in most patients.

Other morphological forms of acute leukemia may progress more persistently, and the long-term results of their treatment are still somewhat worse.

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