Introduction

Lymphopenia is a pathological state where there is an abnormally low concentration of lymphocytes in the blood according to the criteria of specific age groups.¹ For instance, it is diagnosed when the concentration is below 1000 cells/µL for adults and 3000 cells/µL in children under the age of 6.²  However, severe lymphopenia is known to be an especially serious clinical condition which is diagnosed when lymphocyte concentration is below 500 and 2000 cells/µL respectively, thus signifying that early intervention is required to prevent this.² The aetiology of lymphopenia can range from congenital immunodeficiencies to acquired conditions such as infections from HIV, hepatitis, autoimmune disorders, blood cancer and other medical treatments, namely bone marrow transplants. Thus, understanding the signs and symptoms is important in early diagnosis and treatment.

What are the clinical implications?

Having a low lymphocyte count will not only increase the susceptibility to infections such as colds or pneumonia, but it will also delay its responses to vaccines and wound healing due to a compromised immune system. 

Symptoms of lymphopenia typically include fever, cough, and enlarged lymph nodes and spleen. Tuberculosis, skin abnormalities, and unexplained weight loss may also occur under rare circumstances. 

However, due to the diverse roles of lymphocytes, lymphopenia can also affect different organ systems. Examples would be malabsorption and an increased risk of hematologic malignancies such as lymphoma. It also causes proliferation of antigen-experienced T cells, thus increasing the risk of cardiovascular diseases.⁵ Henceforth, it is extremely essential to prevent this from occurring.

Who is at risk of lymphopenia?

Certain people are more at risk if:

• They have had a recent infection or surgery, such as cancer treatment can cause fewer lymphocytes⁴
• They have an underlying condition causing this disease, as seen with some autoimmune disorders and diseases affecting the blood and bone marrow
• They are taking medications that can affect their lymphocyte count, such as corticosteroids, methotrexate, and interferons
• They have participated in alcohol abuse and stress
• They are adults who are malnourished, as the body lacks the protein and nutrients to produce lymphocytes

How is this diagnosed?

A healthcare provider will undertake a medical history, looking for signs and symptoms, as well as asking about lifestyle, such as diet, to identify if nutritional deficiencies are possible causation factors as well.

Certain tests will then be undertaken to diagnose lymphopenia:

• Complete blood count: This counts the lymphocytes in the blood
• Complete blood count with differential: This specifically counts the individual types of white blood cells
• Flow cytometry: Measures the different types of lymphocytes
• Immunoglobulin level test: Measures the levels of antibodies in the blood, which can also diagnose other conditions, such as autoimmune diseases
• Bone marrow analysis: Shows abnormalities in blood cell production, which could also potentially cause lymphopenia

How can this be managed and treated?

The treatment and management of lymphopenia vary depending on the causation of this condition.

A stem cell transplant is used for a patient who was born with defective stem cells and an insufficient number of lymphocytes in the body. This will replace defective stem cells with healthy ones, which will eventually develop into mature blood cells, notably lymphocytes, thus increasing their concentration and potentially curing the patient from lymphopenia.

Apart from that, immunoglobulin shots can also be taken for severe lymphopenia, as this can strengthen the immune system against primary and secondary infections.

It is also common for patients to experience lymphopenia due to certain medications. Therefore, your doctor may change or stop certain prescriptions to raise your lymphocyte count to a healthy level as well.   

For other causes, the following medication or treatment can be undertaken:

• Antiretroviral combination therapy for HIV
• Bone marrow stem cell transplant for cancers affecting the blood and bone marrow
• Antiviral agents, antibiotics, and antivirals can treat specific infections

What is the prognosis for people who have lymphopenia?

The prognosis will depend on the cause and reversibility. Usually, lymphocyte levels will return to normal once the patient has recovered from the infection. But if there is another reason causing the reduced number of lymphocytes, treatment may be longer. Over time, monitoring these lymphocyte levels and clinical symptoms is important in managing the patient’s health.

Summary

Severe lymphopenia is defined as a significant decrease in the number of lymphocytes circulating in the bloodstream, leading to a weakened immune system. This causes serious clinical manifestations with many organ systems having an effect, such as an enlarged spleen and unexplained weight loss, as well as frequent and long-lasting infections. There are many causes of this; examples include immunodeficiencies, infections, and autoimmune disorders. 

There is a range of diagnostic tools used to determine if a patient has this disease, with many measuring the lymphocyte levels. For treatment, medications can help you to prevent infections as well as to treat them if they are the underlying cause. Bone marrow or stem cell transplant can also be used to replace defective stem cells to produce functioning lymphocytes and prevent the risk of infections. Thus, it is extremely crucial for you to have a deep understanding of the signs and symptoms of severe lymphopenia as well as early interventions, and tailored interventions are essential for improved outcomes.  

FAQs

Can cancer treatments cause lymphopenia?

Yes, certain types of cancer treatment, such as radiotherapy and chemotherapy, can lower the levels of lymphocytes in the blood, thus causing it.

Can you prevent lymphopenia?

For some types of lymphopenia, it can be prevented, such as having a healthy diet and reducing alcohol intake, as well as recovering from infections. However, this cannot be prevented if it is inherited instead.