Renal pathologists may throw out the term “full house” immunostaining…what does this mean?
This means quite simply that all five major immunofluorescent stains on a renal biopsy (IgM, IgG, IgA, C3, and C1q) are all positive. The analogy holds true in that the “full house” in cards (3 of a kind plus a pair, to the left) is similar to the 3 types of immunoglobulins plus 2 types of complement which show positive staining.
The classic situation for “full house” immunostaining occurs in lupus nephritis, in which there is immune complex deposition in the subendothelium and subepithelium.
We have a patient with full house immunostaining who does not have typical clinical features of lupus or serology. what is the differential?