Adult T-Cell Lymphoma or Leukemia - Clinical Features, Diagnosis, and Treatment

Introduction:

Each cell in our body has its function. Likewise, the white blood cell of our body plays a significant role in protecting us from various infections. T-cell or T-lymphocyte produced by the bone marrow is one of the white blood cells considered essential components of the immune system. This article describes the T-cell neoplasm (cancer), its causes, characteristics, management, and prognosis.

What Is Adult T-Cell Lymphoma or Leukemia?

Adult T-cell lymphoma or leukemia (ATLL) is a rare and fast-growing neoplasm of the T-cells found in the blood, lymph nodes, skin, and other areas of the body. Its prevalence is high in regions like China, Japan, south and central America, and west Africa.

What Causes Adult T-Cell Lymphoma?

The occurrence of ATLL is highly linked with the human T-cell lymphotropic virus type -1 (HTLV-1) infection. Studies show that HTLV-1 may affect about 10 million individuals around the globe. Of these, 1 to 5 % may develop adult T-cell lymphoma or leukemia. It can occur in any age group and is more commonly found in men than women.

The virus may be transmitted through blood transfusion and sexual interaction. In addition, a child may acquire the disease from the affected mother through breastfeeding.

What Are the Clinical Features of Adult T-Cell Lymphoma?

It is essential to know the types of adult T-cell lymphoma to differentiate its characteristic features; which include:

1) Acute - The acute form of ATLL constitutes more than 50 % of all cases. Its typical features are:

• Hypercalcemia.

• Lymphadenopathy in the neck, underarm, and groin.

• Organ infiltration.

• Skin rash.

• Fatigue.

• High serum lactate dehydrogenase (LDH) level.

2) Chronic - The chronic form affects the skin, lungs, and liver; the calcium and LDH levels remain normal. It consists of two subtypes, namely favorable and unfavorable. The features of the unfavorable subtype involve decreased albumin, elevated LDH, and raised BUN (blood urea nitrogen). These features explain the reason for its poor prognosis.

• Lymphomatous - It is a fast-growing type of ATLL. It constitutes:

• Organomegaly.

• Lymphadenopathy.

• Hypercalcemia.

• A striking increase in LDH levels.

• Smoldering - This form is mild and slow-growing. There is mild or no increase in the LDH levels, average lymphocyte count, and mild skin and lung involvement.

The above-mentioned types suppress the individual’s immunity, thus predisposing them to various fungal, viral, and bacterial infections. The aggressive forms may also affect the central nervous system.

What Are the Diagnostic Methods for Adult T-Cell Lymphoma?

The factors that necessitate the suspects for ATLL are :

• Individuals from endemic areas like South America, Africa, etc.

• History of blood transfusion or exposure to contaminated products.

1) Laboratory Investigation - The laboratory examination includes complete blood count, LDH levels, calcium, potassium, and creatinine levels. These levels are increased in the aggressive types of adult T-cell leukemia or lymphoma.

2) Cytological Examination - The diagnosis is made by determining the CD3, CD4, CD5, and CD7 cell count. It also aids in evaluating the disease severity and monitoring the treatment.

3) Biopsy - A tissue or cell sample is collected to be examined under the microscope. Samples from lymph nodes, skin, or the gastrointestinal tract may aid in diagnosing ATLL. Especially the biopsy of bone marrow aid in the staging of ATLL.

4) Computed Tomography (CT) - The CT scan helps detect the typical features of ATLL, such as lymphadenopathy, organomegaly, and other bone involvement. Even the positron-emission tomography-computed tomography (PET-CT) scan also helps detect various organ infiltration.

5) Magnetic Resonance Imaging (MRI) - The doctor may order an MRI of the brain and a lumbar puncture to evaluate any central nervous system involvement by an aggressive form of ATLL. The lumbar puncture is a procedure that involves the use of a fine needle to aspirate a sample of cerebrospinal fluid (CSF) from the space between two lumbar bones. The collected sample is then sent to a laboratory to detect the presence of cancerous T-cells or other infectious agents.

Can I Live Long With Adult T-Cell Lymphoma?

The prognosis of adult T-cell lymphoma is poor. Even after treatment, the overall- 4-year survival rate is estimated to be:

• Acute - 11 %.

• Lymphomatous - 16 %.

• Chronic - 36 %.

• Smoldering - 52 %.

Also, studies show that the following factors determine the prognosis of ATLL:

• Age over 40 years old.

• High lactate dehydrogenase levels.

• Presence of more than three lesions.

• Hypercalcemia.

What Is the Differential Diagnosis?

The other types of lymphoma may possess similar characteristics to ATLL.

• Anaplastic large-cell lymphoma is a type of T-cell lymphoma affecting the skin, lymph nodes, and other body organs. A biopsy is required to differentiate it from different subtypes of T-cell lymphoma.

Is Adult T-Cell Lymphoma Curable?

The aggressive types, like acute, lymphomatous, and unfavorable subtypes of chronic forms, are treated with antiviral therapy. In contrast, milder forms like smoldering are managed by careful monitoring and antiviral treatment.

1) Antiviral Medication - Zidovudine and Interferon may be helpful in patients with T-cell leukemia.

2) Chemotherapy - The following agents showed improvement in individuals with adult T-cell lymphoma:

• VCAP-AMP-VCEP: Vincristine, Cyclophosphamide, Doxorubicin, Prednisone, Ranimustine, Vindesine, Etoposide, and Carboplatin.

• Modified EPOCH: Etoposide, Prednisolone, Vincristine, Carboplatin, and Doxorubicin.

• CVAD: Cyclophosphamide, Vincristine, Doxorubicin, and Dexamethasone.

• CHOP: Cyclophosphamide, Doxorubicin, Vincristine, and Prednisone. It is recommended for elderly patients who cannot tolerate aggressive treatment.

3) Stem Cell Transplant - These procedures are ineffective in treating ATLL; moreover, studies show poor outcomes after stem cell transplant.

4) Monoclonal Antibody Treatment - Antibodies to fight against cancerous cells are made in the laboratory known, as monoclonal antibodies are infused into the patients.

It includes:

• Brentuximab Vedotin.

• Mogamulizumab.

• Alemtuzumab.

• Daclizumab.

What Are the Complications of Adult T-Cell Lymphoma?

Adult T-cell lymphoma or leukemia decreases the patient’s immunity; therefore, the chances of acquiring opportunistic infections are high. Thus it is necessary to provide immunization and medication against such diseases. Another severe complication of ATLL is tumor lysis syndrome, which releases cancer cell contents into the blood.

Conclusion:

Adult T-cell lymphoma or leukemia is a rare neoplasm, and the prognosis of its aggressive type is inferior. In addition, the risk of acquiring ATLL is high in patients with human T-cell lymphotropic virus type-1 (HTLV-1). Such patients should avoid prolonged breastfeeding and practice precautions during sexual interactions. To conclude, chemotherapeutic and antiviral agents are available and can improve the patient’s survival rate.