Eosinopenia is a laboratory phenomenon characterized by a decrease in the content of eosinophils less than 100 in 1 µl of blood. It is a rather rare occurrence and can occur in severe cases of various infectious diseases, pathologies accompanied by hypercortisolism, and some allergic reactions. The level of eosinophils is examined when calculating the leukocyte formula in a clinical blood test. Correction is carried out as part of the treatment of the underlying disease.
One of the most common causes of eosinopenia is the long-term use of drugs of adrenal cortex hormones - glucocorticosteroids. Glucocorticoids have the ability to reduce the number of leukocytes, including eosinophils, in the peripheral blood by directly destroying them. Therefore, people taking corticosteroids may experience eosinopenia, often against the background of a decrease in the total number of leukocytes (leukopenia).
In itself, the presence of eosinopenia is not considered a reason to cancel hormone therapy, since it does not have a pathological effect on human health. Glucocorticoids are widely used in clinical practice for the treatment of a wide variety of pathologies, such as:
Severe emotional stress tends to stimulate the adrenal glands to produce large amounts of cortisol, which can destroy eosinophils. Eosinopenia can be observed both in healthy people under the influence of significant stress, and in various neuroses - social anxiety disorders, depression, neurasthenia. After elimination of the traumatic factor, psychotherapy, anti-anxiety drugs, antidepressants, the level of eosinophils returns to normal.
As a rule, allergic reactions are accompanied by eosinophilia, i.e. an increase in the number of eosinophils. However, with severe allergic inflammation, on the contrary, the level of eosinophils in the blood decreases. The pathogenesis of this phenomenon is as follows: the allergen that has entered the body causes degranulation of basophils and the release of allergy mediators (histamine, leukotrienes, etc.), as well as eosinophilic chemotactic factor (ECF) anaphylaxis. This factor stimulates the migration of eosinophils from the peripheral blood to the focus of inflammation.
With massive degranulation of basophils, a large amount of ECP is released, as a result of which almost all peripheral blood eosinophils migrate to the focus of inflammation to suppress it, and new eosinophils still do not have time to be synthesized in the bone marrow. Therefore, in the first hours after an attack of a severe allergic reaction (status asthma, angioedema, anaphylactic shock), patients may experience eosinopenia, and sometimes aneosinophilia (complete absence of eosinophils).
eosinopenia
As you know, helminths are able to induce hypersensitivity reactions that occur within a few weeks after infection. Eosinopenia can develop according to the mechanism described above (massive migration of eosinophils to the focus of allergy). It should be noted that eosinopenia in patients with helminthiases is extremely rare, and the vast majority of patients have very high eosinophilia (it can reach 60-70% of the total number of leukocytes).
Eosinopenia may accompany some infectious diseases. Of these, the most relevant today is COVID-19. The mechanism by which eosinopenia occurs in SARS-CoV-2 coronavirus infection is unknown. However, according to the results of clinical observations, eosinopenia that develops in patients with COVID-19 is associated with severe pneumonia.
In such patients, there is an increase in the need for respiratory support (connection to mechanical ventilation) and a high frequency of deaths. Also, a low content of eosinophils is considered a marker of an unfavorable outcome in purulent-septic processes - phlegmon, abscesses.
Since glucocorticoids can have a devastating effect on eosinophils, a constant elevated blood level of adrenal hormones (cortisol) is often accompanied by eosinopenia. Such endocrine pathologies include Itsenko-Cushing's disease (pituitary adenoma that secretes an excess of adrenocorticotropic hormone) and Itsenko-Cushing's syndrome (adrenal corticosteroma that secretes large amounts of cortisol). Eosinopenia is detected already in the early stages of the disease and is leveled after the elimination of hypercortisolism.
Eosinopenia has a fairly wide range of etiological factors, so if it is detected, you should consult a general practitioner. When collecting an anamnesis, it is necessary to clarify whether the patient is taking medications and whether he is registered with a dispensary for a chronic disease. It is also necessary to find out whether the patient has traveled abroad in the last few months, whether he has eaten insufficiently processed meat or fish, unwashed vegetables or fruits.
Much attention is paid to the examination of the patient. So, skin rashes in the form of urticaria indicate the presence of allergies, centripetal obesity, striae on the lateral surfaces of the abdomen are characteristic of hypercortisolism. If COVID-19 is suspected, body temperature, saturation are measured, and lung auscultation is performed. It is specified whether there is a dry cough, difficulty breathing, loss of smell and taste. Additional research methods are assigned, including:
Eosinophil count
The tactics of managing the patient depends on the etiology of eosinopenia and the severity of the patient's condition. Eosinopenia itself does not have a negative effect on the body. Therefore, if it develops against the background of the use of GCS, their cancellation is not required. In case of neurotic disorders, it is necessary to consult a psychotherapist who conducts psychotherapy sessions and prescribes pharmacological drugs (antidepressants, tranquilizers).
Allergy sufferers are advised to avoid contact with the allergen. When COVID-19 is confirmed, in order to prevent the spread of coronavirus infection, patients are transferred to an infectious isolation ward. In severe bilateral pneumonia with respiratory failure (saturation below 90%), connection to a ventilator is indicated.
In the treatment of diseases that can cause eosinopenia, the following drugs are used:
It is worth paying attention to the fact that none of the many antiviral drugs recommended by many experts has shown a positive effect in the treatment of a new coronavirus infection. Also ineffective were drugs prescribed to suppress the inflammatory process in the lungs - synthetic antimalarials and antibiotics from the macrolide group.
Patients with Itsenko-Cushing's disease are shown a neurosurgical operation - transsphenoidal adenomectomy. In Itsenko-Cushing's syndrome, laparoscopic bilateral adrenalectomy is performed, followed by hormone replacement therapy with glucocorticoids and mineralocorticoids. Echinococcal cyst, which is most often localized in the liver, is also subject to prompt removal.
Eosinopenia in some cases can only be an indicator of long-term hormonal therapy. In infections, it is a marker of an extremely unfavorable prognosis. Therefore, its detection requires a thorough examination for timely diagnosis and treatment.