[Interleukin-18 expression in peripheral blood mononuclear cells in children with steroid-resistant nephrotic syndrome].
OBJECTIVE
To examine serum concentration of interleukin-18 (IL-18) and IL-18 mRNA expression in peripheral blood mononuclear cells (PBMCs) in children with primary nephrotic syndrome (PNS) and explore the possible role of IL-18 in steroid-resistant nephrotic syndrome (SRNS).


METHODS
Sixty-six children with newly diagnosed PNS, including 39 cases of steroid sensitive nephrotic syndrome (SSNS) and 27 cases of SRNS, were enrolled. Forty healthy children were used as a normal control group. Blood samples were collected before and 8 weeks after glucocorticoid treatment. Serum concentration of IL-18 was measured using ELISA. IL-18 mRNA expression in PBMCs was detected by the RT-PCR method. The amount of 24-hr urine protein was measured by the biuret method. Serum contents of total cholesterol (T-Ch), triglyceride (TG), low density lipoprotein (LDL), total protein (TP), and albumin (Alb) were measured by the automatic biochemistry analyzer.


RESULTS
Serum concentration of IL-18 and IL-18 mRNA expression in PBMCs in the SSNS and the SRNS groups were significantly higher than those in the normal control group before treatment (P< 0.05). The SRNS group had increased serum protein concentration of IL-18 and IL-18 mRNA expression in PBMCs compared with the SSNS group before treatment (P< 0.05). Serum LDL content in the SRNS group was also significantly higher than that in the SSNS group before treatment (P< 0.05). After treatment, serum concentration of IL-18 and IL-18 mRNA expression in PBMCs in the SRNS group were significantly higher than those in the SSNS and the normal control groups (P< 0.05). Serum concentration of IL-18 and IL-18 mRNA expression in PBMCs in the SSNS group were significantly reduced after treatment, but the alterations of IL-18 were not observed in the SRNS group after treatment.


CONCLUSIONS
SRNS was associated with increased serum IL-18 concentration and IL-18 mRNA expression in PBMCs. Over-production of IL-18 may play a role in the development of SRNS.
Jiang
Hong-Kun
HK
Department of Pediatrics, First Affiliated Hospital, China Medical University, Shenyang, China.
Luo
Gang
G
Jiang
Hong
H
D000293:Adolescent; D000305:Adrenal Cortex Hormones / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D004351:Drug Resistance; D005260:Female; D006801:Humans; D020382:Interleukin-18 / Q000097:blood* / Q000235:genetics / Q000502:physiology; D007963:Leukocytes, Mononuclear / Q000378:metabolism*; D008077:Lipoproteins, LDL / Q000097:blood; D008297:Male; D009404:Nephrotic Syndrome / Q000097:blood* / Q000188:drug therapy; D012333:RNA, Messenger / Q000097:blood
D000305:Adrenal Cortex Hormones; D020382:Interleukin-18; D008077:Lipoproteins, LDL; D012333:RNA, Messenger