36. In the image below shows gel card test for PNH. The patients sample is put into tubes 4,5 and 6 (from left to right). The gel card test shows that patient:-
[1] Has PNH
[2] Doesn’t have PNH
[3] Inconclusive for PNH
[4] None of these
Answer = [1] Has PNH
Explanation:
[Note the tube 1,2,3 From left to right which is done by using Blood from Normal person] Positive reactions of 3+ to 4+ (agglutinated cells forming a red line on the surface of the gel) indicate a normal red cell population with the presence of the corresponding DAF and MIRL antigens. This indicates a negative result for PNH and the PNH-ctl microtube must show a negative reaction (a compact button of cells on the bottom of the microtube).
[Note the tube 4,5,6 From left to right which is done by using Blood from a PNH Patient] Negative reactions indicate the absence of the corresponding DAF and MIRL antigens. Cells lacking CD55 or CD59 do not agglutinate but form pellets at the bottom of the microtube. This indicates a positive result for PNH.
