The Latex-Cold-Precipitate Test in Rheumatoid Arthritis: Experience after Some Years

Conclusion and SummarySeven serological reactions were considered in 114 cases of definite R.A. and in 354 healthy control persons. 300 consecutive positive latexcold- precipitate tests were compared with 300 consecutive positive IIIStep- Tests.The L. C. P. appeared to be a very sensitive reaction (92.1 %) in the R. A.-group with a maximum of 5.3 %of aspecific tests. The sensitivity was only surpassed with 94.7 % by the III-St. T. but against this fact, there are 16.4 % false-positive results. The specificity was only surpassed with 2.5 % by the latex-fixation test of Singer-Plotz but against that, stays a very low sensitivity of 55.3 %.We consider a titer ⩽1/16 to be normal for the L. C. P.The results obtained with the cold-precipitate seem to be of a different nature than those with the Hel precipitate. For the HCI precipitate a titer ⩽1/56 may be considered as normal.The inhibitor-determination of Ziff, owing to its high aspecificity, seems to be unfit for diagnostical purposes. The L. C. P. sometimes is positive, while the inhibitor still can be shown.