A low monocyte count can occur for a variety of reasons, including physical illness, the use of certain medications, or vitamin deficiencies. Illnesses that affect the bone marrow, such as HIV, rheumatoid arthritis, or lupus, are among the most common causes for a low monocyte count. This symptom may also develop as a side effect of some medications or deficiencies in vitamins such as folate and vitamin B-12. Some types of bacterial infections may cause a decrease in this type of white blood cell, although it is more common for infections to develop as a result of the abnormal blood values. Any specific questions or concerns about low numbers of monocytes in an individual situation should be discussed with a doctor or other medical professional.
A monocyte is a type of white blood cell that is produced by the bone marrow and helps to protect the body from foreign invaders, such as harmful bacteria and viruses. When there is a decreased number of monocytes in the blood, the body is more susceptible to illness. In order to create an individualized treatment plan, a doctor may order a variety of diagnostic tests to help determine the exact cause of the low monocyte count.
Medical conditions that suppress the normal functioning of the bone marrow are the most common contributing factors to the development of a low monocyte count. HIV is a virus that can lead to AIDS, a potentially fatal illness that causes the immune system to become severely compromised. Rheumatoid arthritis is thought to be a disease of the immune system and leads to inflammation of the joints. Lupus is another type of autoimmune disease that can cause a low monocyte count and can lead to hair loss, shortness of breath, or even organ failure.
The use of some medications may lead to a low monocyte count. Corticosteroids, oral interferons, and chemotherapy drugs are the most likely to have this side effect. Steroid medications, also known as corticosteroids, are often used to treat conditions that affect the joints, including arthritis and lupus. Oral interferons may be used to treat a variety of medical conditions, including hepatitis, multiple sclerosis, and certain forms of cancer. Chemotherapy drugs contain strong chemicals and are designed to treat those with cancer, especially aggressive forms of cancer that have begun to spread throughout the body.
Nutritional deficiencies, particularly those involving folate or vitamin B-12, may cause a low monocyte count. Simple blood tests at a doctor's office can determine whether these deficiencies are present. Treatment for decreased levels of monocytes depends on the underlying cause of the disorder and may include the use of antibiotics or other medications.