Aggressive Natural Killer Cell Leukemia

Aggressive Natural Killer Cell Leukemia

Article
Digestive Health
Diseases & Conditions
+3
Contributed byKrish Tangella MD, MBASep 26, 2022

What are the other Names for this Condition? (Also known as/Synonyms)

  • Aggressive NK-Cell Leukemia
  • ANKL (Aggressive Natural Killer Cell Leukemia)

What is Aggressive Natural Killer Cell Leukemia? (Definition/Background Information)

  • Aggressive Natural Killer Cell Leukemia (ANKL or Aggressive NK-Cell Leukemia) is a very rare and highly-aggressive cancer that is mostly observed in young and middle-aged adults. The cancer involves the peripheral blood, meaning that the malignant cells are present in peripheral blood
  • It is a rare and severe form of large granular lymphocyte leukemia. Large granular lymphocyte (LGL) leukemia represents a type of lymphoproliferative disorder. Lymphoproliferative disorders are disorders in which there is uncontrolled production of (excess) lymphocytes that occurs due to several reasons
  • There is a strong association of this condition with Epstein-Barr virus infection; however, the cause of Aggressive Natural Killer Cell Leukemia is unknown. Some research scientists believe that it is due to abnormal autoimmune responses, or initiated by certain viral infections
  • Several organs of the body, such as the liver, spleen, and lymph nodes, may be affected. Individuals with Aggressive Natural Killer Cell Leukemia may have severe anemia and thrombocytopenia, which can lead to bleeding disorders
  • Aggressive Variant of T-Cell Large Granular Lymphocyte Leukemia is typically treated using chemotherapy, blood transfusions, and other supportive measures. In some cases, a stem cell or bone marrow transplantation may be undertaken. Typically though, there is a poor response to chemotherapy and other treatment measures
  • Despite intensive therapy, the prognosis of Aggressive Natural Killer Cell Leukemia is extremely poor. Most individuals survive for a period of less than 2 months following diagnosis of the condition

General information on lymphoma and lymphocytes:

  • Lymphocytes are the main white blood cells found in the lymph, which is the fluid of the lymphatic system; just as blood is the fluid of the circulatory system. Lymphocytes are made in bone marrow, and can develop into either B-cells or T-cells. 
  • Large granular lymphocytes (LGLs) are present in peripheral blood in normal adults. The LGLs usually constitute 10-15% of the mononuclear cells in peripheral blood and they fight infections
  • Lymph results from filtration of blood as it travels to and from tissues. Lymph is colorless because it lacks red blood cells; instead, it contains lymphocytes. It is central to the immune system
  • There are 3 different kinds of lymphocytes:
    • T-lymphocytes or T cells: They help combat infections and abnormalities within the cells (cell-mediated immunity). They fight viruses and cancerous cells
    • B-lymphocytes or B cells: They produce antibodies that are bodily defense proteins, which target foreign invaders outside the cells (humoral immunity). They fight bacterial cells, cell fragments, and other immunogenic elements
    • Natural killer cells or NK cells: They perform diverse functions related to both cell-mediated and humoral immunity. They also scout for cancer cells, a process called immune surveillance
  • Large granular lymphocyte leukemias can be of T-cell type or NK-cell type

Who gets Aggressive Natural Killer Cell Leukemia? (Age and Sex Distribution)

  • Aggressive Natural Killer Cell Leukemia is a very uncommon disorder that generally affects adults; some studies indicate a median age of presentation at 41-42 years
  • The condition may affect young adults and adolescents too
  • Some studies report that both men and women are affected equally, while others report that there is a slight male predominance
  • All racial and ethnic groups are affected. Nevertheless, Aggressive NK-Cell Leukemia is rare among non-Asian populations, which implies that it may be more common in individuals of Asian descent

What are the Risk Factors for Aggressive Natural Killer Cell Leukemia? (Predisposing Factors)

The risk factors for Aggressive Natural Killer Cell Leukemia include: 

  • Epstein-Barr virus (EBV) infection
  • Individuals of Asian origin may have a higher risk for the condition

No prominent autoimmune disorder has been reported with Aggressive NK-Cell Leukemia.

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Aggressive Natural Killer Cell Leukemia? (Etiology)

Lymphocytes are a type of white blood cells that are responsible for providing immunity in the human body. B-cells and T-cells are the two different types of lymphocytes. When under certain circumstances, the lymphocytes grow and multiply abnormally, it can result in a form of blood cancer. Leukemia is a group of cancer that affects the blood cells. Since, the peripheral blood is involved; the condition can affect several organs of the body.

The cause of Aggressive Natural Killer Cell Leukemia is unknown.

  • Some researchers believe that large granular lymphocyte leukemias develop due to an abnormal autoimmune response or one that is initiated by certain viral infections. Some believe that LGL leukemia is a persistent autoimmune disorder
  • Research studies have established a strong link between this cancer type and Epstein-Barr virus infection
  • TCR gene rearrangement in Aggressive NK-Cell Leukemia shows germline configuration

What are the Signs and Symptoms of Aggressive Natural Killer Cell Leukemia?

The signs and symptoms of Aggressive Natural Killer Cell Leukemia may include the following:

  • ‘B’ symptoms that may include fever, night sweats, and weight loss
  • Cytopenia (blood cell count reduction), which consists of the following:
    • Decreased red blood cells (anemia), causing fatigue, pale skin, and shortness of breath
    • Decreased white blood cells (leukopenia or leukocytopenia), causing an increased risk for infections
    • Decrease in platelet numbers (thrombocytopenia), resulting in easy bruising, prolonged bleeding, bleeding from the gums or nose, and presence of blood in stool
  • Splenomegaly or enlarged spleen
  • Hepatomegaly or enlarged liver
  • Enlarged lymph nodes (lymphadenopathy) may be noted, with or without pain

The onset of signs and symptoms of Aggressive NK-Cell Leukemia are often sudden.

Depending upon the specific part of the body, or organ affected, the following specific signs and symptoms may be seen:

  • There may be associated autoimmune disorders, which can cause joint and muscle pain, heat intolerance, recurrent rashes, abdominal pain, and a general feeling of illness
  • If the brain is involved, then neurological symptoms such as the following may be observed:
    • Confusion
    • Tinnitus (ringing in the ears)
    • Hearing and visual impairment
  • If the gastrointestinal (GI) tract is involved, then GI tract symptoms such as the following may be observed:
    • Ulcers
    • Diarrhea
    • Inflammation
    • GI bleeding
  • Joint inflammation and fluid accumulation (edema) can occur, if the joints are affected

How is Aggressive Natural Killer Cell Leukemia Diagnosed?

Tests and procedures that could help in the diagnosis of Aggressive Natural Killer Cell Leukemia include:

  • A thorough physical examination and a complete medical history
  • Assessment of presenting symptoms
  • Blood tests that may include:
    • Complete blood cell count (CBC) blood test
    • Absolute lymphocyte count on peripheral blood
    • Liver function blood test (LFT): Increased liver enzymes may be noted
    • Lactate dehydrogenase (LDH) blood test
    • Blood culture, on a case-by-case basis, to rule-out any infections
    • Immunoglobulin studies
    • Southern blot techniques
  • Molecular studies on peripheral blood and/or bone marrow specimen
  • Polymerase chain reaction (PCR) test: It is used to measure the presence of certain biomarkers in blood or bone marrow cells. The test is ultrasensitive and detects extremely low amounts of biomarkers remaining in blood, which can be missed by cytogenetic methods, such as FISH, karyotype, or flow cytometry. PCR allows a more sensitive follow-up of patients in remission and can help determine whether additional treatment is necessary
    • Blood tests, such as PCR techniques and southern blot techniques, are used to determine T-cell receptor (TCR) gene rearrangement clonality
    • In Aggressive NK-Cell Leukemia, TCR gene rearrangement shows germline configuration
  • Flow cytometric analysis on peripheral blood and/or bone marrow specimen: Flow cytometry to identify cells as they flow through an instrument, called a flow cytometer. Flow cytometry measures the number and percentage of cells in a blood/bone marrow sample, and cell characteristics such as size, shape, and the presence of biomarkers on the cell surface. This method helps to sub-classify the condition and to detect residual levels of disease after treatment. This tool can help in diagnosing relapse and restart treatment as needed. Flow cytometric analysis shows the following phenotype of the tumor cells: CD3-, CD56+, and CD16+
    • Radiological imaging may be performed that may include:
      • X-ray of the affected region
      • Ultrasound scan of the affected region
      • Computerized tomography (CT) scan of the abdomen or affected region
      • Vascular radiological studies
      • Whole body bone scan
      • Whole body CT-PET scans if the cancer has spread to other organ systems
      • Brain MRIs are used if neurological symptoms are present, which can help determine if the cancer has spread to the brain, or to tissues that cover the brain
    • Fluorescence in situ hybridization (FISH): It is a test performed on the blood or bone marrow cells to detect chromosome changes (cytogenetic analysis) in blood cancer cells. The test helps in identifying genetic abnormalities that may not be evident with an examination of cells under a microscope
    • Immunophenotyping to identify a specific type of cell in a sample, which can help determine the best treatment course to be followed
    • Bone marrow aspiration and biopsy is performed and sent to a laboratory for a pathological examination, to determine if the bone marrow is involved. Sometimes, the pathologist may perform special studies, which may include immunohistochemical stains, histochemical stains, molecular testing, and very rarely electron microscopic studies. However, a bone marrow biopsy is not needed in the early stages of the condition
    • Lymph node biopsy, when enlarged lymph nodes are present, may be undertaken. The biopsies may be performed under general or local anesthesia. Normally, the entire lymph node is removed
    • Lumbar puncture to determine if the brain is involved
    • In addition, the cerebrospinal spinal fluid (CSF) may be collected by inserting a needle in the spine and subjected to microscopic, flow cytometric, PCR, and biochemical analysis, to diagnose central nervous system (CNS) involvement, if any
    • Exploratory laparoscopy (diagnostic laparoscopy) may be required, if gastrointestinal symptoms are present. In this procedure, the abdomen is examined using a minimally-invasive technique, and a tissue biopsy and tissue for culture obtained. Minimally-invasive approaches help decrease complications and the length of stay at the hospital. A diagnostic laparoscopy is also helpful in staging of the tumor. Nevertheless, this procedure is not very much used
    • Differential diagnoses, to eliminate other conditions, such as Felty syndrome (that presents rheumatoid arthritis, neutropenia and splenomegaly), are often considered, before arriving at a definitive diagnosis

A definitive diagnosis of Aggressive Natural Killer Cell Leukemia is arrived at by a combination of blood tests, special molecular studies, and analysis of symptoms.

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Aggressive Natural Killer Cell Leukemia?

The complications due to Aggressive Natural Killer Cell Leukemia may include: 

  • Multiple organ failure including liver and spleen
  • Involvement of local and distant organs: The disorder can spread from the lymph nodes to other parts of the body, leading to a loss of function of the organ/area to which the cancer has spread
  • Recurrence of the condition
  • Severe bleeding
  • Severe anemia requiring blood transfusions
  • Severe leucopenia leading to recurrent infections
  • Recurrent infections that may be severe
  • Hemophagocytic syndrome
  • Severely decreased immunity can be a complication of Aggressive NK-Cell Leukemia, even during its treatment. Due to this, individuals are more vulnerable to infections; there is an increased risk of developing serious complications from such infections
  • If the condition spreads to the brain and central nervous system, it can give rise to:
    • Inflammation of the meninges or brain (that can be lethal)
    • Headache
    • Vision changes
    • Facial numbness
  • If the abdomen is affected, it can cause intestinal obstruction that results in urine outflow obstruction and kidney damage

There may be complications related to chemotherapy used in treating the condition, which may include:

  • Side effects such as dizziness, vomiting, appetite loss, mouth ulcers, and hair loss
  • By damaging healthy cells, the individual is more open or vulnerable to secondary infections
  • The treatment can also cause infertility in men and women. Hence, measures to protect the individual’s fertility must be considered, before starting chemotherapy

The treatment measures can also give rise to secondary cancers such as skin cancer.

How is Aggressive Natural Killer Cell Leukemia Treated?

Systemic therapy is generally used for Aggressive Natural Killer Cell Leukemia. A combination treatment may be used that includes the following:

  • Chemotherapy: This approach uses a combination of drugs to kill the cancerous cells and can be used in patients, for all stages of Aggressive Natural Killer Cell Leukemia
    • There can be severe side effects including fatigue, nausea, hair loss, anemia, high risk of infection, and drug-specific reactions
    • Chemotherapy can be administered as a pill, liquid, shot, or intravenously
    • However, it has been observed that some patients do not respond to this treatment
  • Targeted treatment with monoclonal antibody

Note: Men and women in child-bearing age would greatly benefit from counseling regarding fertility issues. Some chemotherapy agents can cause infertility in both men and women. There can be permanent damage to the testicles and ovaries, harming their ability to produce sperms or ova. In men, sperm banking can be considered before initiating therapy. In women, in many cases, due to urgency of starting chemotherapy, it is often difficult to perform ovum banking. However, if there is sufficient time prior to chemotherapy, ovum banking may be performed. The healthcare provider may help assess the risk-benefit analysis, depending upon each individual’s specific circumstances.

  • Prednisone therapy - treatment with steroids on a case-by-case basis may be undertaken
  • Administration of hematopoietic growth factors to treat decreased blood counts
  • Blood transfusion
  • If spleen is enlarged, then a surgical removal of the spleen (splenectomy) may be considered
  • Radiation: Radiation therapy is the use of high-energy radiation waves to kill cancer cells, by destroying their DNA
    • This treatment modality is generally used for early stage cancers. It is most commonly used in combination with chemotherapy
    • The radiation may be administered by a machine placed outside the body, or by placing a radioactive material inside the body
    • The side effects of radiation therapy include nausea, vomiting, fatigue, pain, risk of cancer later in life, and risk of heart disease
    • Radiation can damage healthy cells in addition to cancer cells, causing further complications
  • Supportive treatment: Anti-nausea medications and antibiotics may be used as supportive therapy. In combination with other treatment measures, these can help combat the symptoms of immunodeficiency

If Aggressive Natural Killer Cell Leukemia is not fully responsive to treatment, or if the chance of recurrence is high, then bone marrow transplantation or stem cell transplantation can be considered. Again, it has been observed that there is limited success with these treatment modalities too.

  • Bone marrow transplantation: Typically systemic cases may be treated by administering high doses of chemotherapy or radiotherapy. But, high doses of chemotherapy drugs will also damage the bone marrow, preventing it from making any blood cells. Hence, before starting high-dose chemotherapy, the physicians may take out some of the patient’s bone marrow and freeze/preserve it. Collecting the bone marrow is called a bone marrow harvest. The bone marrow is then stored. After high dose chemotherapy or radiation, the bone marrow is thawed and injected back into patient through a drip (transfusion). This is called an autologous bone marrow transplant. Sometimes bone marrow donated by another matching person (usually a brother or sister) is used, if the condition recurs following transplant using one’s own cell. This is called as allogeneic bone marrow transplant
  • Stem cell transplantation: This procedure is similar to bone marrow transplantation and involves the transplantation of healthy blood-forming stem cells into the body. The procedure is also called hematopoietic progenitor cell transplantation. Stem cells can be collected from the bone marrow, circulating (peripheral) blood, and umbilical cord blood. It may either involve an autologous stem cell transplantation, where stem cells are harvested from individuals before treatment and transplanted back into the patient after treatment, or involve an allogeneic stem cell transplantation, where stem cells donated by another matching person (usually a brother or sister) is used, if the condition recurs after stem cell transplant using one’s own cell. This is called as allogeneic stem cell transplant

Note: Allogeneic bone marrow and allogeneic stem cell transplants may have more side effects and complications, and this treatment may not be suitable for every individual. If allogeneic transplants come from a healthy donor with no malignant cells, then the chances of recurrence of the condition may be reduced.

  • In order to prevent infections because the immune system is weakened by Aggressive NK-Cell Leukemia or by its treatment, the patient is kept in an isolated ward and treated with appropriate antibiotics
  • Nowadays, targeted therapies are being developed that can selectively kill the cancer cells. Many of them are in the stage of clinical trials
  • Clinical trials: There may be some newer treatment options, currently on clinical trials, which can be considered for some patients depending on their respective risk factors

The healthcare provider will determine the best course of treatment depending on one’s individual circumstances. Also, follow-up care with regular screening and check-ups are important post-treatment.

How can Aggressive Natural Killer Cell Leukemia be Prevented?

Currently, the cause of Aggressive Natural Killer Cell Leukemia is unknown. Hence, it is not possible to prevent the condition. Nevertheless, considering the following factors may help in general in preventing cancers:

  • Healthy diet and exercise, as well as avoidance of unnecessary exposure to chemicals, may help decrease the risk of cancer
  • Avoiding or stopping smoking
  • Treat infections (such as EBV infection) appropriately
  • Genetic testing in individuals with a family history of cancers
  • In order to avoid a relapse, or be prepared for a recurrence, the entire diagnosis, treatment process, drugs administered, etc. should be well-documented and follow-up measures initiated

Regular medical screening at periodic intervals with blood tests, scans, and physical examinations, are mandatory. Often, several years of active vigilance are crucial and necessary.

What is the Prognosis of Aggressive Natural Killer Cell Leukemia? (Outcomes/Resolutions)

  • Aggressive Natural Killer Cell Leukemia is an aggressive cancer with a high-mortality rate. The prognosis of the condition is very poor; the median survival is less than 2 months after diagnosis
  • The prognosis depends upon a set of several factors, which include:
    • Overall health of the individual: Individuals with overall excellent health have better prognosis compared with those with poor health
    • Individuals with bulky disease have a poorer prognosis
    • Involvement of vital organs may complicate the condition
    • Whether the condition is occurring for the first time, or is recurrent. Recurring conditions have worse prognosis compared to cases that do not recur 
    • Response to treatment: Conditions that respond to treatment have better prognosis compared to tumors that do not respond to treatment
  • The combination chemotherapy drugs used, may have some severe side effects (such as cardio-toxicity). This chiefly impacts the elderly adults, or those who are already affected by other medical conditions. Tolerance to the chemotherapy sessions is a positive influencing factor

Additional and Relevant Useful Information for Aggressive Natural Killer Cell Leukemia:

  • The treatment for Aggressive Natural Killer Cell Leukemia can cause physical and emotional distress; supportive care and encouragement, help positively and can bring a measure of relief to the patients

The following article link will help you understand leukemia and lymphoma (blood cancer):

http://www.dovemed.com/diseases-conditions/leukemia-and-lymphoma/

Was this article helpful

On the Article

Krish Tangella MD, MBA picture
Approved by

Krish Tangella MD, MBA

Pathology, Medical Editorial Board, DoveMed Team

0 Comments

Please log in to post a comment.

Related Articles

Test Your Knowledge

Asked by users

Related Centers

Loading

Related Specialties

Loading card

Related Physicians

Related Procedures

Related Resources

Join DoveHubs

and connect with fellow professionals

Related Directories

Who we are

At DoveMed, our utmost priority is your well-being. We are an online medical resource dedicated to providing you with accurate and up-to-date information on a wide range of medical topics. But we're more than just an information hub - we genuinely care about your health journey. That's why we offer a variety of products tailored for both healthcare consumers and professionals, because we believe in empowering everyone involved in the care process.
Our mission is to create a user-friendly healthcare technology portal that helps you make better decisions about your overall health and well-being. We understand that navigating the complexities of healthcare can be overwhelming, so we strive to be a reliable and compassionate companion on your path to wellness.
As an impartial and trusted online resource, we connect healthcare seekers, physicians, and hospitals in a marketplace that promotes a higher quality, easy-to-use healthcare experience. You can trust that our content is unbiased and impartial, as it is trusted by physicians, researchers, and university professors around the globe. Importantly, we are not influenced or owned by any pharmaceutical, medical, or media companies. At DoveMed, we are a group of passionate individuals who deeply care about improving health and wellness for people everywhere. Your well-being is at the heart of everything we do.

© 2023 DoveMed. All rights reserved. It is not the intention of DoveMed to provide specific medical advice. DoveMed urges its users to consult a qualified healthcare professional for diagnosis and answers to their personal medical questions. Always call 911 (or your local emergency number) if you have a medical emergency!