Mee Kyung Namgoong

Eosinophil cationic protein in Henoch-Schönlein purpura and in IgA nephropathy

In order to identify the relationship between eosinophil activation in Henoch-Schönlein purpura (HSP) and IgA nephropathy, serum eosinophil cationic protein (ECP) was analyzed in both conditions. The soluble interleukin-2 receptor (sIL-2R) was also analyzed. The levels of ECP were significantly higher in HSP patients (mean 9.7±1.8 μg/l) than in a control group (mean 4.6±0.7 μg/l). When the HSP patients were classified into two groups, one with normal urine and one with abnormal urine, the latter showed higher levels of ECP than the former. Levels of ECP were not significantly higher in IgA nephropathy patients than in a control group. The sIL-2R levels were elevated in the serum of HSP and IgA nephropathy patients compared with controls. In conclusion, eosinophil activation may be involved in the pathogenesis of HSP but not in IgA nephropathy.

Predicting Factors for Refractory Kawasaki Disease

Background and Objectives About 10-15% of Kawasaki disease (KD) is refractory to intravenous immunoglobulin (IVIG) therapy. This study was designed to investigate the predicting factors for refractory KD. Subjects and Methods We reviewed retrospectively the clinical records of 77 patients with typical KD admitted at Wonju Christian Hospital from January, 2005, to December, 2008. The variance of laboratory and demographic parameters between the IVIG-responsive group and IVIG-resistant group were analyzed. Thirteen patients with urinary tract infections were randomly collected as a febrile control group. Results Among 77 patients diagnosed with complete KD, 13 patients (16.9%) were IVIG-resistant. The febrile period and hospital days were significantly longer in the IVIG-resistant group than IVIG-responsive group (p<0.001, p=0.002). Serum levels of albumin and sodium were significantly lower in the IVIG-resistant group (p=0.025). The Kobayashi score could differentiate these two groups (p=0.015). Fewer lymphocytes was observed during the subacute phase in the IVIG-resistant group (p=0.032). Coronary arterial dilatations (CADs) were observed in 10.9% (7/64) of IVIG-responders and 38.5% (5/13) of IVIG-resistant patients (p=0.038). Conclusion The percentage of neutrophils and lymphocytes in patients with KD, in addition to known risk factors for refractory KD, may help predict IVIG-resistance in patients with KD.

Atypical hemolytic uremic syndrome: Korean pediatric series.

Atypical hemolytic uremic syndrome (aHUS) is a rare disease with a genetic predisposition. Few studies have evaluated the disease in the Asian population. We studied a Korean pediatric cohort to delineate the clinical characteristics and genotypes.

Elevated Serum Levels of IL-21 in Kawasaki Disease

Purpose The serum level of immunoglobulin (Ig)E has been reported to be elevated in patients with Kawasaki disease (KD). We investigated whether interleukin (IL)-21, rather than IL-4, could be related to elevated serum levels of IgE in KD. Methods Sera from 48 patients with KD and 12 controls with high fever were collected to determine the level of IgE using an immunoassay system and the levels of IL-4 and IL-21 were determined using enzyme-linked immunosorbent assay kits. Results The median IL-21 level of KD patients was significantly elevated, at 499.5 pg/mL (range: <62.5-1,544 pg/mL), whereas that of controls was <62.5 pg/mL (<62.5-825 pg/mL; P<0.001). The median IL-4 level of KD patients was not elevated (4.0 pg/mL; 2.1-7.6 pg/mL). The median level of total IgE in KD patients was 58.0 IU/mL (5-1,109 IU/mL). No statistically significant correlation was found between IL-21 and total IgE levels (Spearmans R=0.2; P=0.19). Conclusions Patients with KD have elevated levels of IL-21 in the serum. IL-21 may play a role in the pathogenesis of KD.

Interleukin-21 Receptor Gene Polymorphisms in Kawasaki Disease

Background and Objectives Interleukin-21 receptor (IL-21R) gene polymorphism is related with the development of systemic vasculitis. In this study, we investigated the polymorphisms of IL-21R gene in patients with Kawasaki disease (KD). Subjects and Methods We genotyped the promoter region of IL-21R gene (-2500 bp to +1 bp) in 100 patients with KD and 100 healthy controls. All study subjects were Korean. We designed five pairs of primers and performed polymerase chain reaction (PCR) and direct sequencing. We analyzed whole promoter sequences of 200 individuals with comparison to reference sequences of IL-21R gene (NG_012222.1/NC_000016.9). Results We found five single nucleotide polymorphisms (SNPs) of which minor allele frequency (MAF) >0.01 in the promoter region of IL-21R gene. Those are -1681 G>T (chromosome site 27411802), -379 G>A (27413104), -332 G>C (27413151, rs2214537), -237 A>T (27413246), and -53 G>A (27413430). There is no significant difference in MAF of each SNP between patients with KD and healthy controls except -237 A>T. Twenty five patients with KD had more than 1 SNP in contrast to only seven healthy controls had. The patients with KD have significantly more IL-21R gene polymorphisms than controls (odds ratio: 3.0, 95% confidence interval: 1.6-5.6, p=0.0005). There was no significant correlation between IL-21R gene polymorphisms and the serum level of IL-21. The serum level of total IgE was not significantly correlated with the presence of IL-21R gene polymorphisms. Conclusion Our data suggest that the genetic susceptibility profile for KD may include IL-21R gene.