Familial occurrence of impaired interleukin-2 activity and increased peripheral blood B cells actively secreting immunoglobulins in systemic lupus erythematosus.
OBJECTIVE
We tested the hypothesis that some abnormalities of immune functions are genetically controlled in patients with systemic lupus erythematosus (SLE).


METHODS
We used a phytohemagglutinin-induced interleukin-2 (IL-2) activity assay and a spontaneous plaque-forming cell assay to evaluate T-cell and B-cell function, respectively, in 34 clinically healthy family members of six SLE probands.


RESULTS
Impaired IL-2 activity was found in 15 of the 29 consanguineous relatives. There was no relation between the household relatives and the nonhousehold relatives; none of the five nonconsanguineous household persons had abnormal results. Results for the B-cell assay were abnormal in 22 of the 29 consanguineous relatives. The B-cell abnormalities were more commonly observed in the consanguineous household relatives; four of the five nonconsanguineous household relatives also had abnormal assay results.


CONCLUSIONS
The findings indicate that the impaired IL-2 activity in relatives appears to strongly correlate with a genetic relationship. Although the evidence favors a genetic basis for the B-cell abnormalities, environmental effects may also contribute to the familial occurrence of these abnormalities.
Sakane
T
T
Department of Internal Medicine, Shimane Medical University, Japan.
Murakawa
Y
Y
Suzuki
N
N
Ueda
Y
Y
Tsuchida
T
T
Takada
S
S
Yamauchi
Y
Y
Tsunematsu
T
T
D000293:Adolescent; D000328:Adult; D000368:Aged; D001402:B-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D002648:Child; D003241:Consanguinity; D005260:Female; D006801:Humans; D007136:Immunoglobulins / Q000235:genetics* / Q000378:metabolism; D007376:Interleukin-2 / Q000235:genetics* / Q000276:immunology; D008180:Lupus Erythematosus, Systemic / Q000235:genetics / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D010375:Pedigree; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism
D007136:Immunoglobulins; D007376:Interleukin-2