BIOMEDICAL SCIENCE

Biomedical Science



Biomedical Science

Q1

As in the given case, the potential diagnoses for a patient presenting with the initial haematological findings are the presence of macrocytosis and pancytopenia. This patient has macrocytic anemia, occurring in the context of pancytopenia. Myelodysplastic syndromes are most common in the elderly and should be included in the differential diagnosis of elderly patients with pancytopenia, even if mild. Bone marrow aspiration and biopsy, with chromosome analysis, is required for diagnosis. This patient's CBC was consistent with myelodysplastic syndrome; however, bilirubin levels are usually normal in such cases (DuPont, 2008: 1525-8).

The most feared cause of macrocytic pancytopenia is aplastic anemia, which is characterized by low counts in all three blood cell lines. Pancytopenia can also result from trapping or pooling of cells in an enlarged spleen, as is often seen in patients with chronic liver disease. This patient did not have splenomegaly, however. The most likely diagnosis in this case is megaloblastic anemia, which is a common cause of macrocytic pancytopenia and by far the most readily treatable cause. Megaloblastic anemia can result from vitamin B12 or folate deficiency. Initially, patients have only a mild anemia with normal white cell and platelet counts. By the time the anemia becomes severe, the white cell and platelet counts almost invariably are decreased. The decrease is usually mild, as in this case. A high bilirubin level is an important clue to megaloblastic anemia.

The consultant carried out a bone marrow aspirate which revealed megaloblastic changes. Pancytopenia in patients with megaloblastic anemia occurs because-even though bone marrow cell production is markedly increased-abnormal DNA synthesis causes precursor cells to die before they can be released into the blood stream. The red cell precursors have already produced hemoglobin, and after they die in the marrow and phagocytosis occurs, their heme is converted to bilirubin-just as in hemolytic anemia, in which the red cells are destroyed in the circulation.

Q2

According to the patient's reported history following infections could he be at higher risk of acquiring and may become the cause of the initial symptoms:

Typhoid fever, also known as enteric fever, is caused by Salmonella serotype typhi. The onset of symptoms usually occurs between 5 and 21 days after ingestion of Salmonela typhi bacteria. Symptoms may include constipation, cough, sore throat, headache, and a rash on the infected individual's chest, as well as the slowing of the heartbeat and enlargement of the liver and spleen (Schiller, 2007: 27-38).

Bacteremia is characterized by infection of tissues surrounding the brain and spinal cord (meningitis) and infection within the bloodstream (sepsis). This condition occurs when Salmonella enter and circulate within an infected individual's bloodstream, and is accompanied by few symptoms.

Reiter's syndrome, which includes and is sometimes referred to as “reactive arthritis” is an uncommon, but debilitating, result of a Salmonella infection. Reiter's syndrome is a disorder that causes at least two of three seemingly unrelated symptoms: reactive arthritis, eye irritation, and urinary tract infection (Hill Gaston & Lillicrap, 2003). The reactive arthritis associated with Reiter's develops when ...