I t is well known that kidney injuries cantend to accompany many severe illnesses such as cardiac diseases, trauma andsepsis, and is an increasingly common and devastating complication inhospitalized patients. Despite improvements in health outcomes in many areasduring recent years, mortality and morbidity rates associated with acute kidneyinjury (AKI) remain very high. Currently, the diagnosis of AKI is predominantlybased on creatinine measurement in serum/plasma. However, creatinine levelsstart to increase late after the onset of disease, which leads to unavoidabledelays in AKI diagnosis and makes treatment largely ineffective. Furthermore,creatinine concentration is considerably influenced by muscle mass and otherfactors that render its clinical use unreliable. Several new early biomarkersof AKI have been suggested recently and kidney injury molecule-1 (KIM-1) isamong the most promising ones.
KIM-1 is expressed on the surface oftubular epithelial cells in the kidney. KIM-1 levels are undetectable in normalkidneys, whereas elevated KIM-1 expression was detected in the ischemic kidneyin the animal model of disease, as well as in humans.
KIM-1 concentration in the urine of healthyhumans is less than 1 ng/ml. Meanwhile, following the ischemic kidney injury itcould be elevated up to 3-7 ng/ml. KIM-1 levels begin to increase as early as 6hours after an ischemic insult and remain elevated for a period of 48 hourspost-injury. KIM-1 is not only a sensitive diagnostic marker but also haspredictive value for AKI in patients undergoing cardiac surgery. Kidney tissuemay suffer from ischemia as a result of drug-related response. Accordingly,KIM-1 could be utilized as a nephrotoxicity biomarker in preclinical studies ofdrug candidates and the Food and DrugAdministration has recently recognized KIM-1 as an appropriate biomarker forrenal injury in preclinical studies of pharmacologic agents. According to somepublications, KIM-1 could also be used for detecting certain types of cancer.
Kidney injury molecule-1 is a transmembraneglycoprotein (339 amino acid residues in length) with an N-terminal ectodomain(270 a.a.r.) that contains immunoglobulin-like and mucin domains. Ectodomain ofKIM-1 could be shed into urine upon ischemic insult and could be detected withthe help of specific antibodies. Due to its simplicity and high specificity,immunodetection of KIM-1 is the method of choice for clinical setting.
HyTest Ltd provides two monoclonalantibodies specific to ectodomain of human KIM-1 (Cat.# 4KM1) and recombinanthuman KIM-1 antigen (Cat.# 8KR6). Antibodies constitute a pair that is suitablefor the measurement of KIM-1 levels in urine by the sandwich ELISA.