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. Author manuscript; available in PMC: 2013 May 1.
Published in final edited form as: Leuk Res. 2012 Mar 2;36(5):581–587. doi: 10.1016/j.leukres.2012.02.001

Table 3.

BA21.1 IgG Specificity and Risks.Specificity, sensitivity and risks associated with elevated BA21.1 IgG were calculated for sera from patients with LGL leukemia and BMF diseases, and for sera from normal controls. BA21 IgG: BA21.1 HI: Specimens with BA21.1 IgG levels greater than the 99% confidence interval limit of normal sera. BA21.1 NRM: Specimens with normal levels of BA21.1 IgG. LGL-BMF: Patients with LGL leukemia and BMF diseases. Normal: Healthy participants.

BA21 IgG SPECIFICITY & RISKS
BA21 IgG LGL-BMF NORMAL SUM PARAMETER
Count of BA21.1 HI 117 1 118 TOTAL # BA21.1 HI
Count of BA21.1 NRM 215 236 451 TOTAL # BA21.1 NRM
Total Count 332 237 569 TOTAL # Tested
Sensitivity of BA21.1 Serology: LGL-BMF 35.2%
Specificity of BA21.1 Serology: LGL-BMF 99.6%
CALCULATION VALUE DESCRIPTION
Positive Predictive Value 99% Ability to predict LGL-BMF disease specimen
Negative Predictive Value 52% Ability to rule out normal specimen
False Positive Rate 0.42% Percent of normal specimens that would have elevated BA21.1 IgG results on this test
Likelihood Ratio 83.5:1 Odds that a LGL-BMF specimen vs a normal specimen will produce elevated BA21.1 IgG
Overall Odds Ratio 128.4:1 Odds that elevated BA21.1 IgG will be found in someone with a LGL-BMF condition vs someone with a normal condition