Table 5.

Analysis of serum samples from 12 patients erroneously diagnosed with choriocarcinoma or gestational trophoblastic disease based on false-positive hCG data ((16)).1

Commercial hCGβ RIA, IU/LBeckman Access hCGβ, IU/LAbbott AxSYM hCGβ, IU/LChiron ACS:180 hCGβ, IU/LDPC Immulite hCG, IU/LBaxter Stratus hCG, IU/LSerono MAIAclone, IU/L
ND2NDNDNDND53ND
NDND150NDNDNDND
NDNDNDND<2NDND
<2ND17NDNDND<2
2830149.7ND<2<2
<2<232<2<2<2133
<2ND33ND<2ND<2
<24.668<2<2<22.0
<2ND93NDNDND3.5
106.61104.54.192.613
11ND145NDNDND3.5
11<2175<2<2ND7.8
Median reported concentration<24.681<2<2<23.5
>10 IU/L reported3 of 91 of 510 of 100 of 50 of 61 of 52 of 9
  • 1 Samples were tested for hCG by the hCGβ RIA and 6 immunometric assays. Samples were coded and tested blindly by multiple external laboratories as described in Materials and Methods. Assay results reported by testing centers as 0, <1, or <2 IU/L were considered at the limit of detection and were recorded as <2 IU/L. False-positive values exceeding 10 IU/L are indicated in bold. All samples were supplied to test centers undiluted.

  • 2 ND, not determined. Insufficient serum available to run test.