Objectives. To compare indirect immunofluorescence (IIF) with immunobl
oting (IB) in the detection of antiribosomal antibodies (anti-P Ab) in
patients with systemic lupus erythematosus (SLE) and to investigate t
he possible association between anti-P Ab with serological and clinica
l findings in SLE, particularly with neurological manifestations. Meth
ods. Serum specimens from 44 SLE patients and 10 healthy subjects were
investigated for anti-P Ab using IB and IIF in rat triple substrate a
nd HEp-2 cells. In SLE patients measurements were made of antinuclear
Ab, anti-DNA ds Ab, anti-Sm Ab, anti-U1RNP Ab, anti-Ro Ab, and anti-La
Ab. Clinical manifestations of SLE were collected retrospectively whe
n the serological investigation was made. Results. Of the 44 serum spe
cimens tested, 9 showed a ribosomal pattern with triple rat substrate;
8 of them were IB positive (sensitivity 88%; specificity 97%); 12 ser
um specimens showed a ribosomal pattern with HEp-2 cells by the IIF te
chnique, 9 were positive by IB (sensitivity 100%; specificity 91%). Al
l ten healthy subjects were negative both with IIF and with IB. The ni
ne patients with anti-P Ab in IB (20.45%) had anti-Ro Ab (55% vs. 37%)
, Anti-Sm Ab (33% vs. 22%, and U1RNP Ab (33% vs. 20%) more frequently
than the 35 negative cases. Central nervous system disease (33 vs. 14%
), and particularly seizures (33% vs. 5%) and psychosis (22% vs. 8%) w
ere more common in cases with anti-P Ab, but as with serological assoc
iations, none of them reached a statistical signification. Conclusions
. IIF with both rat triple substrate and HEp-2 cells is useful for the
presumptive diagnosis of anti-P Ab in patients diagnosed with SLE. No
significant serological or clinical association was found in patients
with anti-P Ab, although neurological disease was more common in thes
e cases.