title: Diagnostic accuracy of serum parathyroid hormone levels in kidney transplant recipients with moderate-to-advanced CKD.
abstract: OBJECTIVE
  Elevated parathyroid hormone (PTH) is used to diagnose high turnover bone disease in chronic kidney disease (CKD). The diagnostic accuracy of PTH in kidney transplant recipients with CKD is unknown.
  
  
  METHODS
  We examined kidney transplant recipients with CKD stages 3 (n = 498) and 4 (n = 141) to determine the sensitivity and specificity of the Kidney/Dialysis Outcome Quality Initiative (K/DOQI)-recommended PTH levels in detecting elevated serum β-CrossLaps (CTX) or osteocalcin (OC) levels. We performed receiver-operator curve analyses to determine CKD stage-specific PTH levels that provide optimal diagnostic accuracy.
  
  
  RESULTS
  PTH below the lower limits of the K/DOQI ranges (35 and 70 pg/ml in CKD stages 3 and 4, respectively) showed sensitivity of >90% in diagnosing increases in biochemical markers. The upper limits (70 and 110 pg/ml), however, showed poor specificity. A specificity of >90% for detecting increased biochemical markers was seen with PTH of >140 and >240 pg/ml in CKD stages 3 and 4, respectively.
  
  
  CONCLUSIONS
  Currently applied cutoffs for PTH in kidney transplant recipients with CKD stages 3 and 4 do not appear to adequately detect increased biochemical markers of bone turnover. Diagnostic uncertainty exists in patients with CKD stage 3 and PTH between 35 and 140 pg/ml, and CKD stage 4 and PTH between 70 and 240 pg/ml.
authors.affiliation: Division of Nephrology, Salem Veterans Affairs Medical Center, Salem, VA 24153, USA. csaba.kovesdy@va.gov
authors.forename: Csaba P
authors.initials: CP
authors.lastname: Kovesdy
authors.forename: Miklos Z
authors.initials: MZ
authors.lastname: Molnar
authors.forename: Maria E
authors.initials: ME
authors.lastname: Czira
authors.forename: Anna
authors.initials: A
authors.lastname: Rudas
authors.forename: Akos
authors.initials: A
authors.lastname: Ujszaszi
authors.forename: Eniko
authors.initials: E
authors.lastname: Sarvary
authors.forename: Csaba
authors.initials: C
authors.lastname: Ambrus
authors.forename: Miklos
authors.initials: M
authors.lastname: Szathmari
authors.forename: Adam
authors.initials: A
authors.lastname: Remport
authors.forename: Istvan
authors.initials: I
authors.lastname: Mucsi
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000175:diagnosis*; D016030:Kidney Transplantation / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood*; D012720:Severity of Illness Index
chemical_list: D015415:Biomarkers; D010281:Parathyroid Hormone