Weakened expression of ABO antigens (making forward grouping reactions weaker than expected) can occur in conditions where red blood cell production is abnormal. Myelodysplastic Syndrome (MDS) is a bone marrow disorder where the body produces poorly functioning, dysplastic blood cells. This dysplasia can affect the proper synthesis and placement of carbohydrates on the cell membrane, including the ABO antigens. As a result, the A or B antigens may be expressed in lower numbers or with an altered structure, leading to weaker agglutination with corresponding antisera. Other conditions like acute leukemia or myelofibrosis can also cause this. In contrast, iron deficiency anemia, polycythemia vera (increase in cell numbers, not necessarily dysplasia), and sickle cell disease do not typically cause weakened ABO antigen expression; in fact, in sickle cell disease, antigen expression may be normal or even increased due to reticulocytosis.

Break down complex topics into smaller, manageable chunks for easier recall.

Zambia

• Joseph Soko – 101 pts

• Visual Pathway Lesions
• Positive and Negative Symptoms
• Hallucinations and Delusions
• Antipsychotic Medications
• Emergency: Environmental Emergencies