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

• Reactive Large Granular Lymphocytosis

What is Transient Large Granular Lymphocytosis? (Definition/Background Information)

• Transient Large Granular Lymphocytosis is a short-term increase in large granular lymphocyte numbers (usually less than 6 months) that may be seen in association with a variety of conditions including viral infections, autoimmune disorders, and non-lymphoid malignancies
• 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. The term “lymphocytosis” indicates an increased number of lymphocytes in peripheral blood
• In Transient Large Granular Lymphocytosis, the increase is usually reactive in nature and non-malignant. Such short-term increase should not be misdiagnosed as LGL leukemias (that are types of blood cancers)
• However, if there are persistent increases in LGLs, diagnostic work-ups or additional studies should be performed to rule out a large granular lymphocyte leukemia (LGLL)
• Transient Large Granular Lymphocytosis may or may not present with any significant symptoms. However, the signs and symptoms of the underlying condition may be observed
• Individuals with Transient Large Granular Lymphocytosis are treated symptomatically. Also, a treatment of the underlying condition is typically undertaken. Treating the underlying condition may help restore the levels of LGLs in blood, in many cases
• Since, the condition is only short-term; the prognosis of Transient Large Granular Lymphocytosis is normally good with adequate treatment. However, the overall prognosis also depends on the type and severity of the underlying condition and the patient’s response to treatment

Who gets Transient Large Granular Lymphocytosis? (Age and Sex Distribution)

• Transient Large Granular Lymphocytosis may be seen in individuals of any age (in both children and adults)
• Both males and females are affected
• It can occur worldwide and all racial and ethnic groups may be affected

What are the Risk Factors for Transient Large Granular Lymphocytosis? (Predisposing Factors)

The following conditions may be associated with Transient Large Granular Lymphocytosis:

• Autoimmune disorders
• Viral infections
• Non-lymphoid malignancies
• Solid organ transplantation

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 Transient Large Granular Lymphocytosis? (Etiology)

The exact cause of Transient Large Granular Lymphocytosis is unknown. 

• A transient increase in the number of large granular lymphocytes is often the cause of a variety of underlying conditions such as viral infections, autoimmune disorders, non-lymphoid malignancies, and solid organ transplantation
• The increase is usually reactive in nature and non-malignant. Besides, by treating the underlying condition, a decrease in LGLs is usually noted

Some researchers believe that it is due to an abnormal autoimmune response or one that is initiated by certain viral infections.

Note: T-cell receptor gene rearrangement may reveal a clonal population, which may occur as a reactive process to an infection. The presence of a clonal T-cell population should not be misdiagnosed as a malignancy, since this is transient (short-term) in nature.

What are the Signs and Symptoms of Transient Large Granular Lymphocytosis?

• Transient Large Granular Lymphocytosis may be asymptomatic in some individuals. In others, it may be symptomatic
• Signs and symptoms of the underlying (associated) condition may be noted

How is Transient Large Granular Lymphocytosis Diagnosed?

Tests and procedures that can help in the diagnosis of Transient Large Granular Lymphocytosis include:

• A thorough physical examination and a complete medical history
• Assessment of presenting symptoms
• Blood tests that may include:
  • Complete blood cell count (CBC)
  • Absolute large granular lymphocytes count on peripheral blood
  • Liver function blood test (LFT)
  • Lactate dehydrogenase (LDH) blood test
  • Blood culture, on a case-by-case basis, to rule-out any infections
  • Rheumatoid factor blood test
  • Antinuclear antibodies (ANA) test
  • Immunoglobulin studies
  • Anti-neutrophil antibodies blood tests
  • 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
• 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 may help in diagnosing relapse and restart treatment as needed
• 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
• 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
• Differential diagnoses, to eliminate other conditions are often considered, before arriving at a definitive diagnosis

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 Transient Large Granular Lymphocytosis?

The complications of Transient Large Granular Lymphocytosis may include:

• Severe bleeding
• Severe anemia requiring blood transfusions
• Severe leucopenia leading to recurrent infections
• Organ (liver or spleen) dysfunction
• Pure red cell aplasia (PRCA) may be observed
• Complications that arise from severity of the underlying condition

How is Transient Large Granular Lymphocytosis Treated?

The healthcare provider may recommend a ‘wait and watch’ approach for asymptomatic Transient Large Granular Lymphocytosis, after a diagnosis of the condition is established. In many cases, treating the underlying condition normally resolves the abnormal increase in LGL numbers.

In individuals with symptoms, the treatment may involve the following measures, depending on the underlying cause and associated symptoms:

• Treating underlying infections, autoimmune disorders, or malignancies
• Immunosuppressive therapy, where necessary
• 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
• 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

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 Transient Large Granular Lymphocytosis be Prevented?

Currently, it is not possible to prevent Transient Large Granular Lymphocytosis.

What is the Prognosis of Transient Large Granular Lymphocytosis? (Outcomes/Resolutions)

• The prognosis of Transient Large Granular Lymphocytosis is generally good in a majority of the individuals with appropriate treatment. Individuals, who do not show symptoms, have better prognosis than those who present symptoms
• However, the overall prognosis depends upon a set of factors that include the type of underlying condition the individual is associated with, the severity of the signs and symptoms of the underlying condition, the health status of the individual, and his/her response to therapy

Additional and Relevant Useful Information for Transient Large Granular Lymphocytosis:

The following article link will help you understand leukemia and lymphoma:

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