What is Reticulosis (Reticulohistiocytosis, Non-lipid Reticuloendotheliosis, Abta-Letterera-Sive Disease)?
Abta-Letterer-Sive disease (true reticulohistiocytosis) was first described by Letterer in 1924. In 1933, Sive made a detailed report on the clinical picture, and Abt summarized in 1936 the results of his own research and literature data on acute reticulohistiocytosis in children. Therefore, the disease is called Abta-Letterera-Siwe disease. A number of synonyms of this disease are used in the literature: diffuse reticuloendotheliosis, aleukemic reticulosis, histiomonocytic acute malignant reticulosis, non-lipid reticulosis, acute reticuloendotheliosis, histiocytosis X, etc.
Causes of Reticulosis (Reticulohistiocytosis, Non-lipid Reticuloendotheliosis, Abta-Letterer-Sive Disease)
The etiology and pathogenesis of reticulohistiocytosis are not completely known. The possibility of a viral or bacterial infection is assumed (in the anamnesis of children, infections are often noted – tonsillitis, otitis media, sepsis, etc.). The steadily progressing course of the disease may indicate a neoplastic nature of the process. A. M. Abezgauz believed that the genetic mutation factor is important in the pathogenesis of the disease.
Pathogenesis during Reticulosis (Reticulohistiocytosis, Non-lipid Reticuloendotheliosis, Abta-Letterer-Sive Disease)
Histopathology: accumulations of histiocytes are found in the skin foci, among which lymphocytes and eosinophils are found. The protoplasm of some histiocytes is foamy, stained with fat. The epidermis can be destroyed due to the pressure of the underlying layers of the skin. In visceral organs, normal structures are replaced by proliferate of large pale reticulohistiocytic cells.
During cytological studies made using a puncture biopsy, 4 types of cells were found in smears among red blood cells, leukocyte and reticulohistiocytic elements. The first type of K.A. Moskachev includes small cells, often of irregular shape, with a mesh or homogeneous protoplasm and usually loose nuclei. The second type is multinuclear (from 4 to 7 nuclei) cells, the nuclei are predominantly round and loose. The third type includes cells containing large, medium and small vacuoles. Cells of the fourth type are represented by macrophages, among which there are multinuclear giants. The nature of cellular infiltrate depends on the form of histiocytosis and on the duration of the lesion. In fresh foci, type 1 cells and eosinophils prevail, with the progression of the process, type 3 cells appear, and then type 4 cells are observed and the number of eosinophils is reduced.
The localization and nature of the elements of the rash in the case of Abt-Letterer-Siw disease are very similar to the manifestations of seborrheic dermatitis, the diagnosis of which is usually made at first. However, a closer examination reveals petechial elements, punctate scars in place of former lichenoid papules, which is not observed with seborrheic dermatitis. The general condition of the child, the nature of the damage to other organs and systems (polyadenopathy, destructive changes in bone tissue, lung damage, otitis media and mastoiditis, hepatosplenomegaly, laboratory data) also speak against seborrheic dermatitis. With difficulties in diagnosis, data from a histological examination of the elements of the rash and lymph nodes help.
Symptoms of Reticulosis (Reticulohistiocytosis, Non-lipid Reticuloendotheliosis, Abta-Letterer-Sive Disease)
The disease usually begins in infancy, sometimes even in the neonatal period, with a sudden increase in temperature to 40 ° C. Then the temperature curve becomes hectic, but sometimes it can be subfebrile. On the scalp, in the area of the shoulder blades, abdomen and chest, there are many hemorrhagic flaky lichenoid papules and petechial elements. Necrosis occurs in the center of the papules, followed by the formation of punctate scars; sometimes infiltrative-tumor formations are observed, leaving larger scars. In some patients with Abta-Letterer-Sive disease, onychia and paronychia are possible. Erosions and hemorrhages are often noted on the mucous membranes of the mouth and vulva.
Characteristic signs are severe polyadenopathy and hepatosplenomegaly. Otitis and mastoiditis, which are resistant to antibiotic therapy and surgical exposure, are often noted. Most patients have bones of the skull, ribs, clavicles, scapula, limbs, pelvis, which is accompanied by soreness and swelling of the soft tissues. On radiographs, lesions, osteoporosis, osteolysis, decalcification zones of a cystic nature, periostitis are determined. Changes in the lungs of an infiltrative, small focal and emphysematous nature can be observed, detected less often physically, and mainly radiologically (increased basal pattern, the formation of cystic cavities, thickening of the walls of the bronchi, the presence of emphysema vesicles).
The general condition of the child deteriorates quite quickly, the appetite disappears, the skin becomes pale, poor weight gain, weakness are noted. In peripheral blood: hypochromic anemia with aniso- and poikilocytosis, leukopenia or leukocytosis with neutrophilia and a left shift in the leukocyte formula to myelocytes; monocytosis is found in a number of patients. The myelogram is characterized by polymorphism of bone marrow cells, sometimes the content of elements of a reticulohistiocytic nature is increased.
Treatment of Reticulosis (Reticulohistiocytosis, Non-lipid Reticuloendotheliosis, Abta-Letterera-Sive Disease)
The appointment of glucocorticoids is pathogenetically justified, since they inhibit the function of the reticulohistiocytic system, stimulate hematopoiesis, normalize metabolism, etc. They are prescribed for a long time – until the clinical signs of the disease disappear. The dose of the drug (in terms of prednisone) should be from 1 to 2 mg per 1 kg of body weight per day. A gradual decrease in the dose of the drug continues for several months, and sometimes years, to a more or less prolonged remission. In cases of intercurrent diseases (ARVI, chickenpox, measles, scarlet fever, etc.), as a rule, an exacerbation of the disease occurs, which dictates the need to increase the dose of glucocorticoid for this period and prescribe antibiotics for 3-4 weeks. Antibiotic courses are periodically repeated. In combination with glucocorticoids, a number of patients are prescribed cytostatic agents (6-mercaptopurine, leukeran, degranol, etc.) for health reasons.
The use of anabolic drugs (dianobol, methylandrostenediol) should be carried out with some caution in order to avoid exacerbation of the pathological process (swollen lymph nodes, tumor-like bone formations), as K. A. Moskacheva rightly warns. Gamma globulin injections, blood transfusion, as well as x-ray therapy on the foci of the affected bone tissue are indicated. Ascorbic acid, B vitamins, especially calcium pantothenate, are prescribed.
Prevention of Reticulosis (Reticulohistiocytosis, Non-lipid Reticuloendotheliosis, Abta-Letterer-Sive Disease)
Prevention of the disease Abta-Letterer-Sive is reduced to the protection of a pregnant woman from various harmful exogenous effects. First of all, ionizing radiation and viral infections, which can adversely affect the fetus and contribute to the disruption of regulatory mechanisms that control the growth and reproduction of reticulohistiocytic cells, should be avoided.
The prognosis is poor with damage to the visceral organs, bone system and other tissues. With sometimes exclusively skin forms of the disease, complex therapy using glucocorticoids leads to recovery. After the onset of clinical, hematological and radiological remission due to the possibility of exacerbation of the disease, especially with intercurrent diseases, children should be under constant medical supervision.