Search

The HNK-1 carbohydrate epitope is a 3-sulfo-glucuronyl residue attached to lactosamine structures on glycoproteins, proteoglycans, or glycolipids mostly expressed in the nervous system. Here, using monoclonal antibodies against the sulfated HNK-1 carbohydrate epitope, we first examined its distribution in developing and adult kidneys, then its expression in kidneys with tubular necrosis and renal neoplasms. This HNK-1 epitope was expressed in the human, rabbit, and rat, but not mouse kidney. It was detected within a subset of epithelial cells in the renal vesicle and in comma- and S-shaped bodies during early stages of nephrogenesis. In ureteral bud derivatives, the epitope was present transiently in the area where the collecting duct fused with the nephron. In the adult kidney, expression of the HNK-1 epitope became mainly restricted to the thin ascending loop of Henle where this epitope was carried by heparan- and chondro-proteoglycan. In pathological conditions, HNK-1 epitope expression increased dramatically in proximal epithelial tubule cells in kidneys with acute tubular necrosis. In tumors, the HNK-1 epitope was expressed in the epithelial component of nephroblastomas and in a subgroup of papillary renal cell carcinomas. These data suggest that molecules carrying the sulfated HNK-1 carbohydrate epitope may play an important role in critical stages of renal development and in the physiology of thin ascending loop of Henle. (J Histochem Cytochem 54:575-584, 2006)

The nonfamilial Carney triad includes paraganglioma, gastrointestinal stromal tumor (GIST), and pulmonary chondroma. Some paraganglioma-GIST diads are familial and inherited in an apparent autosomal dominant manner. The familial paraganglioma-GIST syndrome differs from the Carney triad by the absence of female predilection and predominance of paragangliomas. We report the cases of a 12-year-old boy with a paraganglioma of the organ of Zuckerkandl, and his 13-year-old monozygotic twin with a gastric GIST. These two patients, to our knowledge, are the first to be reported as likely having the familial paraganglioma-GIST syndrome following its description by Carney and Stratakis (Am J Med Genet 2002;108:132–139) in 12 patients from five families. A lifetime follow-up and a periodic search for both tumors are indicated in these patients and their families.