title: Absence of sperm-specific lactate dehydrogenase-x in patients with testis cancer.
abstract: LDH-x is a unique form of lactate dehydrogenase found in germinal epithelium during spermatogenesis. 53 patients with germ cell tumors were screened for the presence of LDH-x in the serum. No patient had detectable levels of the enzyme. 31 of the patients had elevated total serum LDH levels, and the isozyme fraction type 1 and/or type 2 was responsible for the elevation in all cases. LDH is a useful marker in germ cell tumors, but LDH-x is not the responsible isozyme.
mesh_terms: D004796:Clinical Enzyme Tests; D004407:Dysgerminoma / Q000201:enzymology; D006801:Humans; D007527:Isoenzymes; D007770:L-Lactate Dehydrogenase / Q000097:blood* / Q000172:deficiency; D008297:Male; D009373:Neoplasms, Germ Cell and Embryonal / Q000201:enzymology*; D013094:Spermatozoa / Q000201:enzymology*; D013736:Testicular Neoplasms / Q000201:enzymology*
chemical_list: D007527:Isoenzymes; D007770:L-Lactate Dehydrogenase