February 14, 2018
In patients suspected of having Alport syndrome, immunofluorescence staining can be used to detect abnormal expression of various alpha chains of type IV collagen. This biopsy from a young girl with hematuria shows discontinuous staining along Bowman’s capsule and along the glomerular capillary loops for the alpha 5 chain of type IV collagen (green). In a female patient, this mosaic pattern of decreased or absent staining is suspicious for heterozygous X-linked Alport syndrome. Intact staining of the alpha 2 chains (red) serves as a positive internal control for tissue integrity.