Leukostasis
It has been suggested that this article should be split into articles titled Asymptomatic hyperleukocytosis and symptomatic hyperleukocytosis. (discuss) (September 2020) |
Leukostasis (also called symptomatic hyperleukocytosis) is a medical emergency most commonly seen in patients with
Asymptomatic hyperleukocytosis and symptomatic hyperleukocytosis (leukostasis)
Symptomatic Hyperleukocytosis (Leukostasis) is defined by a tremendously high blast cell count along with symptoms of decreased tissue
Symptoms and signs
When a patient has symptomatic leukocytosis, specifically caused by a form of leukemia, it is common to find leukostasis in all their organs. The majority of the time a patient dies from neurological complications (40% of patients die due to neurological conditions) as opposed to particular organ damage. The lungs alone account for approximately 30 percent of leukostasis fatalities. All other organs combined attribute to 30 percent of deaths, with the major outliers being neurological and
Pulmonary signs -
Neurological signs - visual changes, headaches, dizziness, tinnitus, gait instability, confusion, somnolence, coma.
The most common symptom is the patient is usually febrile, which is often linked with inflammation and possible infection.
Less common signs include:
Causes of asymptomatic/symptomatic hyperleukocytosis (leukostasis)
Causes of leukocytosis | ||||
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Neutrophilic leukocytosis (neutrophilia) |
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Eosinophilic leukocytosis (eosinophilia) |
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Basophilic leukocytosis Basophilia |
(rare)[3]
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Monocytosis |
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Lymphocytosis |
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Hyperleukocytosis is very common in acutely ill patients. It occurs in response to a wide variety of conditions, including
For lung diseases such as pneumonia and tuberculosis, white blood cell count is crucial for the diagnosis of the disease, as leukocytosis is usually present.
Specific medications, including
Pathophysiology
The mechanism in which hyperleukocytosis or leukostasis manifests and disrupts
Acute myeloid leukemia - 10 to 20 percent of patients newly diagnosed with this type leukemia have hyperleukocytosis.
Acute lymphoblastic leukemia - 20 to 30 percent of patients newly diagnosed with this type of leukemia have hyperleukocytosis.
Chronic myeloid leukemia - The majority of patients with chronic myeloid leukemia usually have hyperleukocytosis.
The primary pathophysiology of leukostasis is not completely understood, but there are two possible theories.
Theory 1
Increased blood viscosity due to large leukemic blast populations which are less deformable than mature leukocytes may lead to leukostasis. The accumulation of less malleable blast products in the bloodstream accumulate within the microcirculation causing an accumulation of blockages leading to leukostasis.[citation needed]
Theory 2
Hypoxic events in body regions may increase the high metabolic activity of dividing
The combination of these theories, in addition to other events, may lead to hyperleukocytosis.
Diagnosis
White blood counts exceeding 100 x 10^9 / L (100,000 / microL) present symptoms of tissue hypoxia and may signal possible neurological and respiratory distress. Ongoing research has shown that patients have experienced hypoxia at leukocyte levels below 100 x 10^9 / L (100,000 / microL), therefore patients with leukemia need regular neurological and respiratory monitoring when leukocyte counts are approaching 100 x 10^9 / L (100,000 / microL) to decrease chances of tissue hypoxia.
Measurements for arterial pO2 have shown to be falsely decreased in patients with hyperleukocytosis because of white blood cells ability to utilize oxygen.
Spontaneous
Disseminated intravascular coagulation and spontaneous tumor lysis syndrome can develop before and after chemotherapy treatment. Patients undergoing this type of therapy need to be closely monitored before and after, in addition to undergoing prophylactic measures to prevent possible complications.
Prevention
Since leukostasis and hyperleukostasis are associated with leukemia, preventive treatments are taken upon diagnosis.[2]
Patients with hyperleukocytosis associated with leukemia are always considered candidates for tumor lysis syndrome prophylaxis in addition to aggressive intravenous hydration with allopurinol or rasburicase to decrease serum uric acid levels.
Treatment
Treatment includes utilization of
Variants of chemotherapy, including induction chemotherapy, are used to treat both elevated white blood cells counts while simultaneously targeting leukemia cells in the bone marrow.[citation needed]
Prognosis
Prognosis of patients with hyperleukocytosis is dependent on the cause and type of leukemia the patient has. Patients diagnosed with asymptomatic hyperleukocytosis have significantly better survival rates than symptomatic hyperleukocytosis (leukostasis). Preventative measures and contentious monitoring of patients diagnosed with leukemia is critical in receiving treatment as early as possible to prevent and treat hyperleukocytosis.[citation needed]
Recent research
Recent and continuing research has shown that patients have had hypoxia at leukocyte levels below 100 x 10^9 / L (100,000 / microL), therefore patients with leukemia need regular neurological and respiratory monitoring when leukocyte counts are approaching 100 x 10^9 / L (100,000 / microL) to decrease chances of hypoxia.[2]
Leukemia and population types are also believed to be associated with possible symptoms and may require a change in treatment.[2]
Results of Tumor lysis/ consumption of coagulopathy in patients with acute leukemia is much more often than in patients with chronic malignant hematological diseases.[5]
- Data retrieved for reference is 2017
Leukostasis, also known as symptomatic hyperleukocytosis, is a life-threatening complication of various leukemias characterized by an excess of white blood cells in the bloodstream. Hyperleukocytosis is arbitrarily defined as greater than 100,000 white blood cells per microliter of blood. The condition is characterized by abnormal aggregation and clumping of white blood cells in the blood vessels resulting in impaired blood flow and delivery of oxygen to the body's cells. The brain and lungs are the two most commonly affected organs.[6] Leukostasis most commonly occurs with acute myeloid leukemia.
Hyperleukocytosis/leukostasis occurs more commonly, and at lower white blood cell (WBC) counts, in acute myeloid leukemia than in
Signs and symptoms
Individuals affected by leukostasis may present with respiratory symptoms such as
Pathophysiology
The pathophysiology of leukostasis is not well understood.
Diagnosis
The clinical signs and symptoms of leukostasis are non-specific but should be suspected in susceptible individuals with leukemia, a high white blood cell count (e.g., over 100,000), and new-onset neurologic or respiratory signs or symptoms.
A
Laboratory abnormalities seen in those with leukostasis include a markedly elevated white blood cell count (hyperleukocytosis) and electrolyte abnormalities seen with tumor lysis syndrome such as high concentrations of potassium, phosphorus, and uric acid in the blood and a low level of calcium in the blood (due to being bound by high amounts of circulating phosphorus).[7]
Management
It is an acute syndrome requiring aggressive cytoreductive modalities including chemotherapy and/or leukapheresis to both reduce the number of circulating leukocytes and to break apart any aggregates that have already formed. Such rapid and massive lysis of tissue poses a risk of complications (tumor lysis syndrome), but it is necessary to avoid a stroke.
Leukostasis is different from leukemic infiltration, which is a neoplastic process where leukemic cells invade organs.[8]
Prognosis
Leukostasis is a high-risk condition and can lead to significant complications resulting from occlusion of blood vessels, including
Epidemiology
The incidence and prevalence of hyperleukocytosis and leukostasis vary depending on the form of leukemia.[7] Hyperleukocytosis is common in chronic myelogenous leukemia and chronic lymphocytic leukemia, but leukostasis rarely occurs.[7] Similarly, the incidence of hyperleukocytosis in people with acute lymphoblastic leukemia is between 10 and 30% but rarely does this progress to symptomatic leukostasis.[7] The incidence of hyperleukocytosis in acute myeloid leukemia (AML) ranges between 5-20% but leukostasis is less common than hyperleukocytosis in this population; leukostasis tends to occur more often in people with AML with monocytic features.[7]
References
- ^ Schiffer, Charles, MD. "Hyperleukocytosis and Leukostasis". UpToDate. Retrieved 11 November 2017.
{{cite web}}
: CS1 maint: multiple names: authors list (link) - ^ a b c d e f g "Hyperleukocytosis and leukostasis in hematologic malignancies". www.uptodate.com. Retrieved 2017-12-12.
- ^ ISBN 978-1-4160-2973-18th edition.
- ^ Leukocytosis: Basics of Clinical Assessment, American Family Physician. November 2000.
- PMID 23943008.
- ^ PMID 22364832.
- ^ PMID 27018197.
- ^ "Leukostasis". Medical Subject Headings, 2009–2009-02-13. 1995-06-01.