Aplastic Anemia

A general article dedicated to problematic of anemia types can be found here.

 

The words "aplastic anemia" could be translated as "anemia caused by malproduction". It is a little bit imprecise term for a condition where the bone marrow stops producing blood cells. Its inaccuracy is caused by the fact that in majority of cases there is not only arrest in the red blood cells production, but also in white blood cells and platelets creation. 

Causes

There are many possible causes of aplastic anemia. In this article we made a list of those most important and most common.

Toxic substances

A contact with certain compounds such as benzene and similar substances may damage hematopoiesis in bone marrow.

Drugs

It is known that some gold-containing drugs can cause bone marrow suppression. A notorious cause is also an antibiotic called chloramphenicol. The risk of bone marrow damage is very low by chloramphenicol use but when it has already happened then very often with fatal consequences.

Chemotherapy

High doses of anti-cancer chemotherapeutics supress bone marrow very efficiently. Fortunately the doses are designed not to destroy the bone marrow completely and it restores back to normal after some time.

Infections

It is an interesting fact that some infections (especially viral) are somehow able to dampen hematopoiesis in bone marrow. As stated above viruses are the most accused cause like cytomegalovirus, Epstein-Barr virus (that also causes infectious mononucleosis), parvovirus B19 and others.

Unknown reasons

In many cases there is no clear root of bone marrow suppression no matter the examinations we perform.

Symptoms

We can distinguish three main groups of symptoms – symptoms of the lack of red blood cells, white blood cells and shortage of blood platelets.

 

The lack of red blood cells manifests by classic symptoms of anemic syndrome. Most of them are related to reduced capacity of our blood to transport breathing gases. Typical symptoms are muscle weakness and fatigue. The muscles of our body do not get enough oxygen and therefore they will get soon tired. Also the brain can suffer from the lack of oxygen; the person often faints or feels dizzy. Less red blood cell numbers with hemoglobin level decrease causes pale color of skin and mucous membranes. This is evident mainly in the conjunctivas. In normal humans they are pink but they turn white by an anemic patient.

 

Anemic person feels weakness and shortness of breath during physical activities. It mimics a heart or lung disease. These organs are however not the cause of the problem. They work properly to get enough of oxygenated blood to tissues but with the lack of hemoglobin they simply can’t be successful.

 

The lack of white blood cells causes the inability to defend against microorganism infections and also increases a possibility of a tumor formation. It is followed by immunodeficiency and more frequent and more serious infections. In the long term, more frequent malignant tumors would emerge but the affected person usually dies before that because of infectious complications.

 

As platelets play a vital role in bleeding stopping (hemostasis) their shortage leads to hemorrhage. In case of disruption of the vascular wall integrity platelets reach such location and create a plug (blood clot) that prevents blood leakage from the affected vessel. Lack of platelets is thus reflected by increased bleeding. There is often bleeding into the skin and mucous membranes, large bruises appear on the skin. Even small open injuries have a tendency to bleed for a longer time; the affected person may find blood in stool, blood in urine and suffers from nosebleed.

Diagnosis

It is always suspicious when some of the symptoms named above appear. A sample of blood is very important because it shows us a general shortage of red blood cells, white blood cells and platelets. A bone marrow puncture can be performed, often a special needle from sternum which is called sternal puncture. By such examination we find a lack of cells and platelets. Bone marrow trephine biopsy is more accurate and helps us to obtain a full sample of bone marrow tissue to study.

Treatment

The treatment is fully in hands of experienced hematologists. Generally speaking, if the bone marrow stops working for any reason and the condition does not improve, the bone marrow transplant is needed. Some drugs are used with often an overall good effect such as corticosteroids but let’s leave the explanation of their particular effect to skilled hematologists.