[Use of an immunofluorescence method and a flocculation test with DNA-sensitized bentonite particles in the serodiagnosis of disseminated lupus erythematosus (SLE)].

The determination of antibodies against native DNA is of great importance in the solution of the diagnostic and therapeutic problems of dissiminated lupus erythematodes. The practical results are in a direct dependence on the laboratory methods for their determination. The diagnostic significance of two methods was studied with the present investigation: indirect immunofluorescent test and flocculation test with DNA-sensibilized bentonite particles. Under the conditions of the investigation, with the aid of the first method, antibodies against native DNA were found in 86.1 per cent of the sera of lupus nephropathy patients as well as in 13.3 per cent of the sera of patients with renal diseases not associated with LED. High serum titres including up to 1/128, were observed only in LED cases. The continuous persistence of antibodies against LED is also characteristic for the latter. The flocculation test was positive in 60.7 per cent of the sera investigated only with LED cases. The conclusion is that both methods could more wisely be used in LED immunodiagnostic because they combine high sensitivity with specificity of reaction, are easy to perform and no expensive material and apparatuses are required.