A positive antibody screen (reaction with screening cells) but a negative antibody identification panel (no clear pattern of reactivity with panel cells) is a relatively common and frustrating scenario in the blood bank. Possible explanations include: 1) **An antibody to a low-frequency antigen (LFA)**: The screening cells possess the antigen, but the panel cells, by chance, lack it. 2) **A weak autoantibody** reacting non-specifically. 3) **Non-specific reactivity** due to rouleaux, abnormal proteins (e.g., in myeloma), or drug interference. 4) **An antibody to a high-frequency antigen (HFA)** where most panel cells are positive, but the pattern is weak and variable. 5) **Technical issues** (e.g., dirty glassware, over-centrifugation). The approach involves: testing additional panel cells (especially those with LFAs), using different techniques (enzymes, different AHG reagents), performing an autocontrol, checking patient history/diagnosis, and possibly testing family members' cells. If no specificity is found, the blood bank must issue the 'least incompatible' blood and monitor the patient closely.

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Zambia

• Joseph Soko – 101 pts

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