CTLA-4 +49 A/G genotype and HLA-DRB1 polymorphisms in Turkish patients with Henoch-Schönlein purpura

Infection Rates Before and After Diagnosis of IgA Vasculitis in Childhood: A Population-wide Study Using Non-exposed Matched Controls

OBJECTIVE

Clinical data suggest that infections can trigger IgA vasculitis (IgAV), but longterm observations are lacking. We compared rates, types, and microorganisms for serious infection before and after diagnosis for children with IgAV and non-exposed controls.

METHODS

Using population-based administrative linked health datasets we estimated incidence rates (IR) for serious infection per 1000 person-months for patients with IgAV (n = 504, age 5 yrs, 59.1% males) and controls matched for age, sex, and year of presentation (n = 1281, age 6 yrs, 66% males). Time zero (T0) was the date of IgAV diagnosis or equivalent date in controls, lookback (median 38 mos) was the period prior to T0, and followup (median 239 mos) was the period after T0.

RESULTS

During lookback, prevalence of serious infection was similar in patients with IgAV and controls (11.5% vs 9.5%, respectively), but patients with IgAV had a higher rate of upper respiratory tract infections [incidence rate ratio (IRR) 1.79; 95% CI 1.39-2.31] with shorter time between first serious infection and T0 (27 vs 43 mos; p = 0.02). During followup, patients were at a constant increased risk for serious infections (IRR 1.46, 95% CI 1.35-1.58). These rates were higher during followup: sepsis (IRR 12.6), pneumonia (IRR 6.19), upper respiratory tract infections (IRR 2.36), and skin infections (IRR 1.85). There was little overlap between patients with serious infections in the lookback and followup periods.

CONCLUSION

In patients with childhood IgAV there is an increased longterm risk for a broader spectrum of infections, which is unrelated to serious infections prior to diagnosis or treatment. This suggests disease-specific factors may have a lasting effect on immune competence in childhood IgAV.

Cutaneous Manifestations of Small-Vessel Leukocytoclastic Vasculitides in Childhood

In childhood, cutaneous small-vessel vasculitides include Henoch-Schönlein syndrome, a systemic vasculitis, and Finkelstein-Seidlmayer syndrome, a skin-limited vasculitis. Both Henoch-Schönlein and Finkelstein-Seidlmayer syndromes are seen more frequently in white or Asian compared with black children and occur especially in winter and spring with a male-to-female ratio of approximately 2:1. In everyday clinical practice, both conditions are diagnosed on clinical grounds without histological confirmation. The characteristic cutaneous hallmarks of Henoch-Schönlein syndrome include a purpuric rash in all and a subcutaneous edema in approximately every second case, which are often preceded by non-specific red or pink macular elements that mimic a non-itching urticarial rash. Recent data point out that Henoch-Schönlein children often present further cutaneous findings such as Köbnerization, Rumpel-Leede capillary fragility phenomenon, and blistering eruptions. Children with Finkelstein-Seidlmayer syndrome are usually ≤24 months of age and not ill-appearing. They present with (a) large, round, red to purpuric plaques (often with a targetoid appearance) predominantly over the cheeks, ears, and extremities and (b) often tender non-pitting edema of the distal extremities, ears, and face (without pruritus). Both in Henoch-Schönlein syndrome and Finkelstein-Seidlmayer syndrome, there is often scrotal involvement. The cutaneous findings remit without sequelae within 2 months in Henoch-Schönlein and 3 weeks in Finkelstein-Seidlmayer syndrome.

HLA-DRB1 gene polymorphisms in Iranian children with Henoch-Schönlein purpura

BACKGROUND

People of all ages can suffer from Henoch-Schönlein purpura (HSP), but it is the most common vasculitis in childhood. The most important involving gene is located on chromosome 6p21.3, a region coding for human leukocyte antigens (HLAs). Among HLA genes, because of the high rate of polymorphisms, HLA-DRB1 is estimated to have a strong association with HSP. In this study, we aimed to assess the association of HLA-DRB1 alleles with HSP in Iranian children.

MATERIALS AND METHODS

This study consisted of thirty Iranian children with HSP and 35 healthy controls. Genomic DNA was extracted, and HLA typing was performed by polymerase chain reaction with sequence-specific primers technique.

RESULTS

The results have shown that HLA-DRB1*01 and HLA-DRB1*11 (P = 0.002, odds ratio [OR] = 7.579, confidence interval [CI] = 1.934-29.697 and P = 0.039, OR = 3.333, CI = 1.030-10.788), respectively, are the most frequent alleles associated with HSP in Iranian children population. The frequency of other alleles was not significantly different in both groups. The results also show no correlation between HLA types and disease manifestations.

CONCLUSION

According to these results, there is an association between HLA-DRB1*01 and HLA-DRB1*11 gene polymorphisms and susceptibility to HSP in our study group.

Henoch-Schonlein purpura, post-streptococcal glomerulonephritis and acute rheumatic carditis after Group A β-haemolytic streptococcal infection

Besides association with acute rheumatic fever (ARF) and acute glomerulonephritis (APSGN), in up to 40% of cases, Group A β-haemolytic streptococcal (GABHS) infections are also implicated as a trigger for Henoch-Schonlein purpura (HSP). A 7-year-old girl with GABHS throat infection who developed HSP, APSGN and rheumatic carditis is reported. She presented with palpable purpura and arthritis in both ankles and later developed carditis characterised by mitral/aortic regurgitation and glomerulonephritis characterised by mixed nephritic/nephrotic syndrome. She had a raised anti-streptolysin titre (ASOT), blood urea nitrogen and creatinine and hypocomplementaemia (C₃), and renal biopsy demonstrated endocapillary and extracapillary proliferative glomerulonephritis with crescents. Immunofluorescence microscopy demonstrated a 'full house' of immunoglobulin and complement, viz. IgA + 2, IgG + 3, IgM + 2, C₃c + 1, Clq + 2 with predominantly IgG deposition. One week earlier, her 4-year-old sister had presented to another hospital with HSP complicated by microscopic haematuria, nephrotic-range proteinuria and gastro-intestinal involvement, and with raised ASOT and low C₃ levels. Although HSP has been associated with either ARF or APSGN, this is the first case of a child with HSP, ARF and APSGN in combination.

Association of TLR4 gene polymorphisms with childhood Henoch-Schönlein purpura in a Chinese population

Recent studies demonstrated that aberrant activation of Toll-like receptor (TLR) 4 was involved in the pathogenesis of Henoch-Schönlein purpura (HSP). In this study, we evaluated the association between TLR4 gene polymorphisms and the risk of childhood HSP in a Chinese population. A total of 175 HSP patients and 186 controls were recruited in this case-control study. Three single-nucleotide polymorphisms of the TLR4 gene (rs1927914, rs10759932 and rs1927907) were genotyped using the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and Sequenom MassARRAY system. Our results revealed that a significantly reduced risk for HSP was associated with the G allele (OR = 0.71; p = 0.023) and G/G genotype (OR = 0.49; p = 0.021) of rs1927914. We also showed that rs1927914 variant decreased the risk of HSP in recessive inheritance model (OR = 0.55; p = 0.035, G/G vs A/A + A/G). In addition, we observed that a significantly decreased frequency of the haplotype GTC (rs1927914-rs10759932-rs1927907) in HSP patients compared with controls (OR = 0.56; p = 0.028). Our data suggested that TLR 4 rs1927914 polymorphism was associated with the decreased susceptibility to HSP in the Chinese children.

[Association between CTLA-4 gene polymorphism and Henoch-Schönlein purpura in children]

OBJECTIVE

To investigate the association between CTLA-4 gene polymorphism and Henoch-Schönlein purpura (HSP) in children.

METHODS

Sixty children who were diagnosed with HSP were enrolled as the case group, consisting of 33 males and 27 females. Thirty healthy children were enrolled as the control group. The patients were further divided into HSP nephritis (HSPN) and non-HSPN groups (n=30 each) according to the presence or absence of nephritis. Polymerase chain reaction-restriction fragment length polymorphism was used to analyze the genotype and allele frequencies at +49 and -1722 loci.

RESULTS

AA, AG, and GG genotypes were detected at +49; neither genotype nor allele frequencies showed significant differences between the case and control groups, between the HSPN and non-HSPN groups, and between male and female patients (P>0.05). TT, TC, and CC genotypes were detected at -1722; neither genotype nor allele frequencies showed significant differences between the case and control groups and between male and female patients (P>0.05). There were significant differences in CC genotype frequency and T and C allele frequencies between the HSPN and non-HSPN groups (P<0.05). Combinational analysis of +49 A/G and -1722 T/C showed no significant differences in the genotype frequency between the case and control groups and between male and female patients (P>0.05). GG-CC combination showed a significant difference between the HSPN and non-HSPN groups (P<0.05).

CONCLUSIONS

CTLA-4 +49 A/G polymorphism is not associated with HSP. CC genotype and C allele of CTLA-4 -1722 and the combination of GG at +49 A/G and CC at -1722 T/C may be risk factors for HSPN.

Pathogenesis and gastrointestinal manifestations of IgA vasculitis

Immunoglobulin A (IgA) vasculitis is a form of leukocytoclastic vasculitis of small vessels, clinically characterized by purpuric skin lesions unrelated to any underlying coagulopathy, gastrointestinal manifestations, arthritis and/or arthralgia and renal involvement. The etiology remains unknown, but various triggers including infections, vaccination, drugs and malignancy have been hypothesized to be associated with the development of IgA vasculitis. Although the pathogenesis has not been completely figured out, genetic predisposition, aberrant glycosylation of the hinge region of IgA1, activated complements, cytokines and chemokines were put out to play important roles in the immunopathogenesis of IgA vasculitis. Histologically, the infiltration of small blood vessels with polymorphonuclear leukocytes and the presence of leukocytoclasia are typical pathologic findings in IgA vasculitis. The treatment is usually supportive, and advanced treatments include immunosuppressive drugs (glucocorticoids and immunosuppressive agents), hemopurification and surgery. The prognosis depends on the age at the disease onset and the renal involvement or not.

Advances in our understanding of the pathogenesis of Henoch-Schönlein purpura and the implications for improving its diagnosis

Henoch-Schönlein purpura (HSP) is a leukocytoclastic vasculitis classically characterized by palpable purpura, arthritis, abdominal pain and renal disease. In this article, we summarize our current understanding of the pathogenesis of HSP and the implications for improving its diagnosis. Although the pathogenesis of HSP is not fully understood yet, exciting new information has emerged in recent years, leading to a better understanding of its pathogenesis. Here, we discuss genetic predisposition, immunoglobulins with a particular emphasis on IgA1, activated complements, cytokines and chemokines, abnormal coagulation and autoantibodies in the underlying pathogenic mechanisms. Finally, diagnostic criteria for HSP developed by institutions such as the American College of Rheumatology and the European League against Rheumatism/Paediatric Rheumatology European Society were proposed to improve early detection and diagnosis.

Lack of association between macrophage migration inhibitory factor gene promoter (-173 G/C) polymorphism and childhood Henoch-Schönlein purpura in Turkish patients

Henoch-Schönlein purpura (HSP) is a small-vessel vasculitis of autoimmune hypersensitivity with rash, arthritis, abdominal pain and renal involvements. Macrophage migration inhibitory factor (MIF) is a immunoregulatory proinflammatory cytokine, and a major mediator at the inflammatory sites. The pathogenesis of HSP has not been fully elucidated. Here we aimed to assess the influence of macrophage migration inhibitory factor gene (-173 G/C) polymorphism in the susceptibility and clinical expression of patients with Henoch-Schönlein purpura (HSP). HSP patients (n:139) and ethnically matched healthy controls (n:100) were genotyped by PCR-RFLP. Genotype analysis of both polymorphisms did not reveal a significant deviation from Hardy-Weinberg equilibrium in any group (p > 0.05). No significant difference was obtained in genotype distribution (p > 0.05) and allele frequencies (p > 0.05) between patients and controls. A statistically significant genotype-phenotype correlation was not obtained when HSP patients were stratified by the presence of certain systemic complications and the macrophage migration inhibitory factor gene (-173 G/C) polymorphism (p > 0.05). A significant risk was not observed in the subjects both with the GC+CC genotype (p = 0.06, OR: 0.5538, 95% CI: 0.2985-1.0274) and C allele (odds ratio: C vs. G: 1.799, 95% CI: 1.002-3.23, p = 0.05). Our findings suggest that MIF gene -173 G/C polymorphism is not associated with HSP in the present Turkish population.

Association between HLA-A and -B polymorphisms and susceptibility to Henoch-Schönlein purpura in Han and Mongolian children from Inner Mongolia

We examined a possible association between HLA-A and -B polymorphisms and susceptibility to Henoch-Schönlein purpura (HSP) in Han and Mongolian children in Inner Mongolia, through a case-control study. Two hundred and sixty-eight unrelated children were enrolled, including 56 Mongolian and 50 Han children with HSP, 66 healthy Mongolian and 96 healthy Han children as a control group. HLA-A and -B alleles were indentified by PCR-sequence-specific oligonucleotide analysis and were further analyzed by PCR-sequencing-based typing (SBT). Frequencies of HLA-A*11, HLA-B*15 in Mongolian patients and HLA-A*26, HLA-B*35, HLA-B*52 in Han patients were higher than those in the corresponding control group (P < 0.05), while frequencies of HLA-B*07 and -B*40 in Mongolian HSP patients were lower than those in the control group (P < 0.05). Further analysis using PCR-SBT showed that all HLA-A*11 were HLA-A*1101, and most HLA-B*15 were HLA-B*1501 in Mongolian HSP patients. All HLA-A*26 were HLA-A*2601 and HLA-B*35 were mostly HLA-B*3503 in Han patients. There were more Han patients with severe manifestations than Mongolian patients (P < 0.05). Frequencies of HLA-A*26, HLA-B*35 and HLA-B*52 in Han patients were higher than in Mongolian patients (P < 0.05). We conclude that HLA-A*11(*1101) and -B*15(*1501) are associated with susceptibility to HSP in Mongolian children and HLA-A*26(*2601), HLA-B*35(*3503) and HLA-B*52 are associated with susceptibility to HSP in Han children. HLA-B*07 and -B*40 may be protective genes in Mongolian children. The different frequencies of HLA-A and -B in Mongolian and Han children may be responsible for the different manifestations in these two ethnic groups.

CTLA-4, position 49 A/G polymorphism associated with coronary artery lesions in Kawasaki disease

OBJECTIVE

Kawasaki disease (KD) is a systemic vasculitis of unknown etiology and primarily affects children less than 5 years of age. Cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) has been suggested as a candidate gene for conferring susceptibility to autoimmunity. This study examined the correlation of CTLA-4 gene polymorphisms in KD with and without coronary artery lesions (CAL).

MATERIALS AND METHODS

A total of 233 KD patients and 644 controls were subjected to determination of CTLA-4 polymorphisms at (-318) C/T and (+49) A/G positions by restriction fragment length polymorphism. Susceptibility, CAL, and intravenous immunoglobulin treatment response of KD were then analyzed with genetic variants.

RESULTS

Polymorphisms of CTLA-4 (+49 A/G) and (-318 C/T) were not significantly different between normal children and patients with KD. The CTLA-4 (+49) A allele (AA+AG genotype), however, was significantly associated with CAL formation, especially in female patients.

CONCLUSIONS

This study provides the first evidence supporting the association of CTLA-4 (+49) A/G polymorphism with the CAL formation of KD particularly in female patients.

Geno-transcriptomic dissection of proteinuria in the uninephrectomized rat uncovers a molecular complexity with sexual dimorphism

Investigation of proteinuria, whose pathophysiology remains incompletely understood, is confounded by differences in the phenotype between males and females. We initiated a sex-specific geno-transcriptomic dissection of proteinuria in uninephrectomized male and female Sabra rats that spontaneously develop focal and segmental glomerulosclerosis, testing the hypothesis that different mechanisms might underlie the pathophysiology of proteinuria between the sexes. In the genomic arm, we scanned the genome of 136 male and 111 female uninephrectomized F2 populations derived from crosses between SBH/y and SBN/y. In males, we identified proteinuria-related quantitative trait loci (QTLs) on RNO2 and 20 and protective QTLs on RNO6 and 9. In females, we detected proteinuria-related QTLs on RNO11, 13, and 20. The only QTL overlap between the sexes was on RNO20. Using consomic strains, we confirmed the functional significance of this QTL in both sexes. In the transcriptomic arm, we searched on a genomewide scale for genes that were differentially expressed in kidneys of SBH/y and SBN/y with and without uninephrectomy. These studies identified within each sex differentially expressed genes of relevance to proteinuria. Integrating genomics with transcriptomics, we identified differentially expressed genes that mapped within the boundaries of the proteinuria-related QTLs, singling out 24 transcripts in males and 30 in females, only 4 of which (Tubb5, Ubd, Psmb8, and C2) were common to both sexes. Data mining revealed that these transcripts are involved in multiple molecular mechanisms, including immunity, inflammation, apoptosis, matrix deposition, and protease activity, with no single molecular pathway predominating in either sex. These results suggest that the pathophysiology of proteinuria is highly complex and that some of the underlying mechanisms are shared between the sexes, while others are sex specific and may account for the difference in the proteinuric phenotype between males and females.

Renin-angiotensin system gene polymorphisms in children with Henoch—Schönlein purpura in West China

It has been suggested that renin-angiotensin system (RAS) gene polymorphism is involved in the pathogenesis of Henoch—Schönlein purpura (HSP) with conflicting reports. We therefore investigate the effect of RAS gene polymorphism on HSP susceptibility and severity in a Chinese cohort. The study included 142 children with HSP and 218 healthy controls that were genotyped for RAS gene polymorphisms. Significantly, differences of T174M-T and ACE-D frequency were found between HSP patients and controls ( palleo = .002, ORalleo = 2.001; palleo = .007, OR alleo = 1.533, respectively). We also found correlations between ACE-I/D and Agt T174M with multiple organ involvements, with significant differences in ACE-D in renal groups ( p < 0.05) and Agt T174M in non-renal ( pjoint = .002, pGI = .042). Furthermore, decreasing M235T-T and increasing ACE-D were found associated with serious renal complications ( p = .019, p = .016). Additionally, ACE-I/D and T174M were significantly associated with high clinical score patients, as opposed to low clinical score patients, when patients were scored depending on the severity of overall complications ( p = .045, p = .026). We suggest that RAS gene polymorphisms ( ACE-I/D, M235T or T174M) are significantly associated with susceptibility to HSP, organ involvement, and disease severity, which largely account for individual prognosis.