I. Noel et al., TOXOPLASMA INFECTION AND SYSTEMIC LUPUS-ERYTHEMATOSUS - ANALYSIS OF THE SEROLOGICAL RESPONSE BY IMMUNOBLOTTING, Journal of Clinical Pathology, 46(7), 1993, pp. 628-632
Aims-To examine the serological response of patients with systemic lup
us erythematosus (SLE) and toxoplasma infection and to compare the blo
t profiles with those from immunocompetent subjects of similar immune
response. Methods-Forty serum samples from patients with SLE were test
ed for toxoplasma antibodies using the dye and indirect haemagglutinat
ion tests. Specific IgM was measured by mu-capture enzyme linked immun
osorbent assay (ELISA). The sera were immunoblotted using antigen stri
ps prepared from the RH strain of Toxoplasma gondii. For comparison, c
ontrol blots were prepared from pooled sera from immunocompetent subje
cts with serological evidence of acute (pool 1), or chronic (pool 2) t
oxoplasma infection, or with no evidence of infection (pool 3). Result
s-Some of the blot profiles from the patients with SLE were compatible
with the corresponding serology but others showed considerable variat
ion, particularly among the IgM blots. The blots from sera with low dy
e test titres suggested that the latter could be false positive result
s. Conclusions-Toxoplasma infection may enhance the production of auto
antibodies which, when combined with the high titres characteristic of
SLE, might interfere in the dye test and other serological tests. Imm
unoblotting could prove useful in the immunocompromised for confirming
the presence of specific toxoplasma antibodies and for the staging of
infection in those with positive serology.