TY - JOUR
T1 - Diagnostic Utility of Complement Serology for Atypical Hemolytic Uremic Syndrome
AU - Sridharan, Meera
AU - Go, Ronald S.
AU - Abraham, Roshini S.
AU - Fervenza, Fernando C.
AU - Sethi, Sanjeev
AU - Bryant, Sandra C.
AU - Spears, Grant M.
AU - Murray, David L.
AU - Willrich, Maria A.V.
N1 - Funding Information:
Grant Support: This project was funded by the Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN.
Publisher Copyright:
© 2018 Mayo Foundation for Medical Education and Research
PY - 2018/10
Y1 - 2018/10
N2 - Objective: To investigate the clinical utility of a 9-analyte complement serology panel (COMS) covering complement function (CH50 and AH50), components (C3, C4), factor B (CFB), factor H, and activation markers (C4d, Bb, and soluble membrane attack complex) for the diagnosis of atypical hemolytic uremic syndrome (aHUS). Methods: Physician orders for COMS from January 19, 2015, through November 4, 2016, were reviewed. Demographic characteristics, patient diagnosis, and laboratory parameters were recorded. Results: There were 177 COMS orders for 147 patients. The median patient age was 44.9 years (range, 0.9-88.0 years). Common reasons for ordering COMS included monitoring and diagnosis of C3 glomerulopathy and renal dysfunction and differentiation of aHUS from other thrombotic microangiopathies (TMAs). Forty-four patients had COMS ordered for TMAs: 8 had aHUS and all had 1 or more abnormalities within the alternative pathway of complement. Although the sensitivity of this finding for the diagnosis of aHUS is 100%, the specificity is only 28%, with a positive likelihood ratio of 1.39. Patients with aHUS had lower CH50, C3, and CFB than did those with secondary non-aHUS TMA (all P<.01). A combined CFB of 20.9 mg/dL or less and CH50 of 56% or less led to sensitivity of 75% with increased specificity of 88.9% and a diagnostic odds ratio of 24. Conclusion: A COMS abnormality should not be interpreted in isolation. In conjunction with clinical presentation, a decrease in both CFB and CH50 may be an important clue to support the diagnosis of aHUS.
AB - Objective: To investigate the clinical utility of a 9-analyte complement serology panel (COMS) covering complement function (CH50 and AH50), components (C3, C4), factor B (CFB), factor H, and activation markers (C4d, Bb, and soluble membrane attack complex) for the diagnosis of atypical hemolytic uremic syndrome (aHUS). Methods: Physician orders for COMS from January 19, 2015, through November 4, 2016, were reviewed. Demographic characteristics, patient diagnosis, and laboratory parameters were recorded. Results: There were 177 COMS orders for 147 patients. The median patient age was 44.9 years (range, 0.9-88.0 years). Common reasons for ordering COMS included monitoring and diagnosis of C3 glomerulopathy and renal dysfunction and differentiation of aHUS from other thrombotic microangiopathies (TMAs). Forty-four patients had COMS ordered for TMAs: 8 had aHUS and all had 1 or more abnormalities within the alternative pathway of complement. Although the sensitivity of this finding for the diagnosis of aHUS is 100%, the specificity is only 28%, with a positive likelihood ratio of 1.39. Patients with aHUS had lower CH50, C3, and CFB than did those with secondary non-aHUS TMA (all P<.01). A combined CFB of 20.9 mg/dL or less and CH50 of 56% or less led to sensitivity of 75% with increased specificity of 88.9% and a diagnostic odds ratio of 24. Conclusion: A COMS abnormality should not be interpreted in isolation. In conjunction with clinical presentation, a decrease in both CFB and CH50 may be an important clue to support the diagnosis of aHUS.
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U2 - 10.1016/j.mayocp.2018.07.008
DO - 10.1016/j.mayocp.2018.07.008
M3 - Article
C2 - 30286829
AN - SCOPUS:85053844824
VL - 93
SP - 1351
EP - 1362
JO - Mayo Clinic Proceedings
JF - Mayo Clinic Proceedings
SN - 0025-6196
IS - 10
ER -