TY - JOUR
T1 - Diagnosis of neuromyelitis spectrum disorders
T2 - Comparative sensitivities and specificities of immunohistochemical and immunoprecipitation assays
AU - McKeon, Andrew
AU - Fryer, James P.
AU - Apiwattanakul, Metha
AU - Lennon, Vanda A.
AU - Hinson, Shannon R.
AU - Kryzer, Thomas J.
AU - Lucchinetti, Claudia F.
AU - Weinshenker, Brian G.
AU - Wingerchuk, Dean M.
AU - Shuster, Elizabeth A.
AU - Pittock, Sean J.
PY - 2009/9
Y1 - 2009/9
N2 - Objective: To compare the sensitivity and specificity of immunofluorescence (IF) and immunoprecipitation (IP) assays using green fluorescent protein-tagged aquaporin-4 (AQP4) in 6335 patients for whom serological evaluation was requested on a service basis. Design: Case-control study. Setting: Mayo Clinic Neuroimmunology Laboratory (Rochester, Minnesota) and Departments of Neurology (Rochester, Minnesota; Scottsdale, Arizona; and Jacksonville, Florida). Patients: Group 1, 835 Mayo Clinic patients, 100 with a neuromyelitis optica (NMO) spectrum disorder diagnosis and 735 without NMO spectrum disorder; group 2, 5500 non-Mayo Clinic patients. Main Outcome Measure: Sensitivity and specificity of each assay for NMO or NMO spectrum disorder, individually and combined. Results: In group 1, the sensitivity rates for NMO were IF, 58%; IP, 33%; and combined assays, 63%. The sensitivity rates for relapsing longitudinally extensive transverse myelitis were IF, 29%; IP, 6%; and combined assays, 29%. The specificity rates for NMO and relapsing longitudinally extensive transverse myelitis were IF, 99.6%; IP, 99.3%; and combined assays, 99.2%. In group 2, NMO-IgG was detected by IF in 498 of 5500 patients (9.1%) and by IP in 331 patients (6.0%); 76 of the 331 patients seropositive by IP (23%) were negative by IF. Clinical information was available for 124 patients (including 16 of those seropositive by IP only); 123 had a definite NMO spectrum disorder and 1 was at risk for NMO (monophasic optic neuritis). Conclusions: In this large, clinical practice-based study, NMO-IgG detected by IF or IP was highly specific for NMO spectrum disorders. The IP assay was significantly less sensitive than IF. Combined testing improved sensitivity by 5%.
AB - Objective: To compare the sensitivity and specificity of immunofluorescence (IF) and immunoprecipitation (IP) assays using green fluorescent protein-tagged aquaporin-4 (AQP4) in 6335 patients for whom serological evaluation was requested on a service basis. Design: Case-control study. Setting: Mayo Clinic Neuroimmunology Laboratory (Rochester, Minnesota) and Departments of Neurology (Rochester, Minnesota; Scottsdale, Arizona; and Jacksonville, Florida). Patients: Group 1, 835 Mayo Clinic patients, 100 with a neuromyelitis optica (NMO) spectrum disorder diagnosis and 735 without NMO spectrum disorder; group 2, 5500 non-Mayo Clinic patients. Main Outcome Measure: Sensitivity and specificity of each assay for NMO or NMO spectrum disorder, individually and combined. Results: In group 1, the sensitivity rates for NMO were IF, 58%; IP, 33%; and combined assays, 63%. The sensitivity rates for relapsing longitudinally extensive transverse myelitis were IF, 29%; IP, 6%; and combined assays, 29%. The specificity rates for NMO and relapsing longitudinally extensive transverse myelitis were IF, 99.6%; IP, 99.3%; and combined assays, 99.2%. In group 2, NMO-IgG was detected by IF in 498 of 5500 patients (9.1%) and by IP in 331 patients (6.0%); 76 of the 331 patients seropositive by IP (23%) were negative by IF. Clinical information was available for 124 patients (including 16 of those seropositive by IP only); 123 had a definite NMO spectrum disorder and 1 was at risk for NMO (monophasic optic neuritis). Conclusions: In this large, clinical practice-based study, NMO-IgG detected by IF or IP was highly specific for NMO spectrum disorders. The IP assay was significantly less sensitive than IF. Combined testing improved sensitivity by 5%.
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U2 - 10.1001/archneurol.2009.178
DO - 10.1001/archneurol.2009.178
M3 - Article
C2 - 19752303
AN - SCOPUS:70349109251
SN - 0003-9942
VL - 66
SP - 1134
EP - 1138
JO - Archives of neurology
JF - Archives of neurology
IS - 9
ER -