This Case
With the panel done 2 weeks post-transfusion, 5 panel cells that were Jk(a+) reacted and 5 that were Jk(a-) did not. This yields a p value of 0.004, which is less than the standard of 0.05, and therefore is more than acceptable statistically.

In other words, an antibody other than anti-Jk^a would be expected to produce these panel results only 4 times in 1000 (which is pretty unlikely).

Th true p value is much lower because many more cells were tested than in the panel alone.

Concluding that the antibody is anti-Jk^a is further strengthened because the patient's red cells type as Jk(a-).

Learning points: The most important things to know about statistical tools such as p values are that they

1. Relate to the probability of getting the observed results if the null hypothesis were true (the panel results were due to another antibody)
   
2. Do not substitute for technical and clinical judgment.