What are immunofluorescence findings for glomerular lesions?

1. Location of deposits a. Extramembrane deposits: immune complexes are located on the external side of the MBG (between the MBG and the podocyte). b. Endomembranous deposits: immune complexes are located within the MBG (mesangial,intercapillary) and subendothelial. c. Intramembranous deposits, immune complexes located in the basement membrane, are much rarer. 2. Appearance of immunofluorescence deposits a. Granular: the most frequent, corresponding to immune deposits. b. Linear: rarer (GN with anti-MBG antibodies, certain diseases with monoclonal Ig deposits). c. Larger and more homogeneous deposits: "hyaline" deposits of HSF, diabetes / amyloidosis. 3. Nature of immunofluorescence deposits a. Immunoglobulins (IgA, IgG, IgM, kappa, lambda). b. Fraction of the complement