Risk due to Elevated Uric Acid Levels in Children With Henoch-Schonlein Purpura

PURPOSE

To compare uric acid levels in children with Henoch-Schonlein purpura (HSP)without nephritis and with renal damage, and at different pathological grades.

METHODS

A total of 451 children were enrolled in this study, including 64 with HSP without nephritis and 387 HSP with kidney damage. Age, gender, uric acid, urea, creatinine and cystatin C levels were reviewed. Pathological findings of those with renal impairment were also reviewed.

RESULTS

Among the HSP children with renal damage, 44 were grade I, 167 were grade II and 176 were grade III. There were significant differences in age, uric acid, urea, creatinine and cystatin C levels between the two groups (p<0.05, all). Correlation analysis showed that uric acid levels in children with HSP without nephritis were positively correlated with urea and creatinine levels (p<0.05). Uric acid levels in HSP children with renal damage was positively correlated with age, urea, creatinine and cystatin C levels (p<0.05, all). Regression analysis found that, without adding any correction factors, there were significant differences in uric acid levels between the two groups; however, after adjusting for pathological grade, there was no longer a significant difference.

CONCLUSIONS

There were significant differences of uric acid levels in children with HSP without nephritis and with renal impairment. Uric acid levels in the renal impairment group were significantly higher than that in the HSP without nephritis group. Uric acid levels were related to only the presence or absence of renal damage, not to the pathological grade.

Therapeutic Potential of Carbon Monoxide (CO) and Hydrogen Sulfide (H2S) in Hemolytic and Hemorrhagic Vascular Disorders-Interaction between the Heme Oxygenase and H2S-Producing Systems

Over the past decades, substantial work has established that hemoglobin oxidation and heme release play a pivotal role in hemolytic/hemorrhagic disorders. Recent reports have shown that oxidized hemoglobins, globin-derived peptides, and heme trigger diverse biological responses, such as toll-like receptor 4 activation with inflammatory response, reprogramming of cellular metabolism, differentiation, stress, and even death. Here, we discuss these cellular responses with particular focus on their mechanisms that are linked to the pathological consequences of hemorrhage and hemolysis. In recent years, endogenous gasotransmitters, such as carbon monoxide (CO) and hydrogen sulfide (H₂S), have gained a lot of interest in connection with various human pathologies. Thus, many CO and H₂S-releasing molecules have been developed and applied in various human disorders, including hemolytic and hemorrhagic diseases. Here, we discuss our current understanding of oxidized hemoglobin and heme-induced cell and tissue damage with particular focus on inflammation, cellular metabolism and differentiation, and endoplasmic reticulum stress in hemolytic/hemorrhagic human diseases, and the potential beneficial role of CO and H₂S in these pathologies. More detailed mechanistic insights into the complex pathology of hemolytic/hemorrhagic diseases through heme oxygenase-1/CO as well as H₂S pathways would reveal new therapeutic approaches that can be exploited for clinical benefit.

Fra-2 is a novel candidate drug target expressed in the podocytes of lupus nephritis

Lupus nephritis (LN) is a common and devastating complication caused by systemic lupus erythematosus. In this study, we evaluated the expression and mechanism of Fos-related antigen 2 (Fra-2) in LN. The results showed that Fra-2 was significantly increased in kidney biopsies of LN patients compared with healthy controls and other kidney disease in glomerular podocytes. The MRL/lpr mouse strain is a murine model of lupus, and it was used to study the mechanisms of Fra-2 in LN. The results showed that Fra-2 was expressed in the glomerular podocytes. We investigated the effects of inflammatory stimuli on Fra-2 protein expression in the glomerular podocytes, and found that interferon gamma was most effective at increasing Fra-2 protein expression. Knockdown of Fra-2 using siRNA enhanced the protein expression of nephrin. Therefore, Fra-2 may be a specific drug target for podocyte injury in LN.

Evaluation of TGF-β1 and MCP-1 expression and tubulointerstitial fibrosis in children with Henoch-Schönlein purpura nephritis and IgA nephropathy: A clinical correlation

OBJECTIVES:

Henoch-Schönlein purpura nephritis and immunoglobulin A nephropathy are two diseases with similar clinical presentations but very different prognoses. Transforming growth factor β1 and monocyte chemoattractant protein-1 have been associated with the development of tissue fibrosis. We examined the development of tubulointerstitial fibrosis and its relationship with Transforming growth factor β1 and monocyte chemoattractant protein-1 expression in these patients.

METHODS:

Renal tissue samples were collected by renal biopsy from 50 children with Henoch-Schönlein purpura nephritis and 50 children with immunoglobulin A nephropathy. Hematoxylin and eosin and Masson's trichrome-stained tissues were examined using light microscopy. Tubulointerstitial fibrosis was graded using the method described by Bohle et al. (1). The immunohistochemical detection of Transforming growth factor β1 and monocyte chemoattractant protein-1 expression was correlated with the tubulointerstitial fibrosis grade. Clinical Trial registration number: ZJCH-2012-0105.

RESULTS:

Transforming growth factor β1 and monocyte chemoattractant protein-1 expression in the renal tissues was significantly greater in the patients with immunoglobulin A nephropathy than in the patients with Henoch-Schönlein purpura nephritis (both p<0.001). The immunoglobulin A nephropathy patients had a higher tubulointerstitial fibrosis grade than the Henoch-Schönlein purpura nephritis patients (p<0.001). The tubulointerstitial fibrosis grade was in accordance with the Transforming growth factor β1 and monocyte chemoattractant protein-1 expression levels in both diseases (both p<0.001).

CONCLUSION:

Transforming growth factor β1 and monocyte chemoattractant protein-1 expression was associated with the development of immunoglobulin A nephropathy and Henoch-Schönlein purpura nephritis. Further studies are needed to better evaluate this association.

A retrospective comparison of skin and renal direct immunofluorescence findings in patients with glomerulonephritis in adult Henoch-Schönlein purpura

BACKGROUND

Henoch-Sch¨onlein purpura (HSP) is a vasculitis tha tcan affect the skin and kidneys. It is characterized by immunoglobulin(Ig) A-predominant deposition in small blood vessels. To our knowledge, there has been no comparison of direct immunofluorescence (DIF) findings in skin and kidney biopsy specimens.

METHODS

We retrospectively studied 21 adults with HSP who had IgA deposition in the skin and kidneys. The skin and kidney DIF findings were compared and tested for an association with the progression of renal disease.

RESULTS

Mean age of the patients was 51.4 years. Follow-up data were available for 19 patients, of whom 5 had progression to chronic kidney disease or renal failure. Concordance between DIF findings onskin and renal biopsies was 100% for IgA, 80% for C3, 80% for IgG,71% for IgM and 53% for fibrinogen. A worse renal outcome was associated with renal IgG deposition (p=0.04). A trend for worse renal outcome was found with renal fibrinogen and skin IgM deposition(p=0.10 and 0.14, respectively).

CONCLUSIONS

In this retrospective study of adult HSP, theconcordance between DIF findings in skin and kidney specimens was low-moderate. Further study is required to elucidate the mechanisms responsible for these differences in Ig deposition.

[Effects of transcription factor T-bet, GATA-3, FoxP3 and CD4(+)CD25(+)regulatory T cells in pathogenesis of child Hench-Schonlein purpura]

The aim of this study was to investigate the effects of transcription factors T-bet, GATA-3 in the pathogenesis of Hench-Schonlein purpura (HSP) in children, the relationship between CD4(+)CD25(+)regulatory T cells, transcription factor FoxP3 and the development of child HSP, and the molecular mechanisms of Th1/Th2 imbalance of child HSP at acute phase, so as to may provide a new approach and strategy for the treatment of HSP at the molecular levels. The expression of T-bet, GATA-3 and FoxP3 mRNA were detected by real time PCR using SYBR Green I in 46 patients with HSP at acute phase and 30 healthy children as controls. The expression of T lymphocyte subsets CD4(+)CD25(+) in peripheral blood mononuclear cells was detected by flow cytometry. The results showed that the relative level of GATA-3 mRNA in peripheral blood mononuclear cells of patients with HSP was significantly higher than those of the control group (964.30 ± 655.18 vs 78.09 ± 57.20, P < 0.01). The relative level of T-bet mRNA in peripheral blood mononuclear cells of patients with HSP was lower than those of the control group (53.98 ± 35.79 vs 181.56 ± 96.90, P < 0.01). The expression level of FoxP3 mRNA with HSP was lower than that of the control group (32.17 ± 23.04 vs 147.91 ± 99.15, P < 0.01). The result of CD4(+)CD25(+) Treg with HSP was lower than those of the control group [(5.34 ± 2.51)% vs (7.85 ± 1.97)%, P < 0.01)]. It is concluded that Th1/Th2 imbalance exists in acute phase of child HSP, especially predominant activation of Th2, which correlates with the abnormal expression of transcription factor T-bet and GATA-3 mRNA. At acute phase of child HSP, the expression of CD4(+)CD25(+)Treg and its special transcription factor FoxP3 mRNA are down-regulated. Treg cells decreases, which indicates that insufficient immunosuppressive effects resulting from the reduction of Treg cells may be one of the important reason in the immune imbalance of HSP acute phase. This study provides experimental evidence for illustrating the pathogenesis of HSP from the molecular mechanism of Treg cells and its regulation, and also provides a new thinking and new strategies for the treatment of HSP at molecular levels.

Investigation of the change in CD4⁺ T cell subset in children with Henoch-Schonlein purpura

Helper T (Th) cells comprising Th1, Th2, Th17, and Treg are involved in the pathogenesis of various vascular inflammations, and information about Th cells in Henoch-Schonlein purpura (HSP) is still controversial. The aim of our study was to investigate the changes in CD4(+) T cell subsets and their roles in the pathogenesis of HSP. Thirty children with diagnosis of HSP and thirty age-matched healthy controls were enrolled in this study. Real-time PCR was used to evaluate the mRNA expression levels of transcriptional factors and cytokines of CD4(+) T cells. Proportions of Th1, Th2, Th17, and Treg cells in peripheral blood were detected by flow cytometry. Plasma cytokine concentrations were measured by ELISA. The proportions of Th2 and Th17 cells increased significantly in children with acute HSP (P < 0.05), while there were no significant differences between HSP and healthy controls regarding the proportions of Treg cells and Th1 cells (P > 0.05). mRNA levels of transcriptional factors and cytokines of Th2 and Th17 cells were significantly up-regulated (P < 0.05), while the differences were not significant as to those of Th1 and Treg cells (P > 0.05). Plasma concentrations of IL-17A, IL-4, and IL-6 in patients with HSP were found to be much higher than those of the control group (P < 0.05), and no differences between IFN-γ, IL-12, and TGF-β were detected between the two groups (P > 0.05). Presence of higher proportions of Th2 and Th17 cells in patients with HSP could be closely correlated with aberrant creation of antibody and development of vessel vasculitis. The changes in cytokine milieu in peripheral blood may play an important role in the derangement of CD4(+) T cell subset.

Kidney is in trouble with mediators

The kidneys receive 20-25 % of cardiac output and play a main role in the control of cardiovascular homeostasis. It is an endocrine organ that regulates and produces many substances, scavenger particles and immune complexes. Cytokines, growth factors, reactive oxygen metabolites, bioactive lipids, proteases, vasoactive substances such as nitric oxide (NO), adrenomedullin (AM), urotensin-II (U-II), have been released in several diseases, and kidney is one of mostly affected organs in body. Some of these mediators act in a paracrine fashion while some act in autocrine. They play important roles in modulating the cardiovascular responses, renal hemodynamics, and probably in mediating the clinical and laboratory manifestations of several renal diseases. These mediators are like "a double edged sword". While small amounts of them mediate many physiological events, little excess may cause the damage to the healthy cells. Many investigators have searched the role(s) of mediators in several diseases. However, the findings are mostly like the model of "chicken and egg", and indistinguishable as to whether they are the causes of, or results of the diseases. We will discuss mainly the possible roles of NO, AM and U-II in children with several renal diseases and summarize what is known, and what must be known about these mediators.

[Renal expression of macrophage migration inhibitory factor in children with Henoch-Sch-nlein purpura nephritis]

OBJECTIVE

To examine the expression of macrophage migration inhibitory factor (MIF) in renal tissues obtained from children with Henoch-Sch-nlein purpura nephritis (HSPN).

METHODS

The renal tissue samples were obtained from 11 children with different pathological grades of HSPN and 8 children with thin glomerular basement membrane disease (controls). The MIF expression was measured by immunohistochemistry. The correlation between MIF expression and 24 hrs urinary protein excretions was evaluated using a linear correlation analysis.

RESULTS

MIF expression was seldom found in renal tissues obtained from controls. However, a significantly increased MIF expression was found and was concordant with the increased severity of renal pathology in renal tissues obtained from children with HSPN. The MIF expression in renal tissues of grade III-IV of renal pathology was significantly higher than that in grade I-II in children with HSPN (p<0.01). In children with HSPN, there was an increased MIF expression in renal tissues with crescent formation and inflammatory cell infiltration. Renal MIF expression was significantly positively correlated with 24 hrs urinary protein excretions in children with HSPN (p<0.01).

CONCLUSIONS

MIF may play an important role in renal injury of HSPN. Up-regulation of MIF expression may reflect the degree of renal lesions in HSPN.

Toll-like receptors 2 and 4 cell surface expression reflects endotoxin tolerance in Henoch-Schönlein purpura

We aimed to analyze the Toll-like receptor (TLR)2 and TLR4 expressions, which are known to be involved in the recognition of pathogens by the innate immune system, in patients with Henoch-Schönlein purpura. Twenty-three patients (10 males, 13 females, aged 4-16 years) with a clinical diagnosis of Henoch-Schönlein purpura were enrolled. Twenty healthy age-matched children (10 males, 10 females) served as controls. TLR2 and TLR4 expression levels on peripheral blood mononuclear cells (PBMCs) were determined by flow cytometric analysis. PBMCs were cultured with heat shock protein (HSP) 60 (1 microg/ml) as an endogenous ligand for TLR. Levels of TLR2 and TLR4 expression on PBMC were significantly lower in the Henoch- Schönlein purpura patients compared to healthy controls when stimulated with HSP60 and with lipopolysaccharide (LPS) (p < 0.05 for both). There was no significant difference between the stimulated and unstimulated samples from the patients. The lower TLR response to these ligands among these patients may reflect a tolerance to bacterial antigens. Further studies will clarify whether tolerance to microbial antigens may have a role in the pathogenesis and course of Henoch-Schönlein purpura.

[Serum and urine VEGF concentration of different pathological types in children with Henoch Schonlein purpura nephritis]

OBJECTIVE

To explore the relationship between vascular endothelial growth factor (VEGF) concentration in urine and renal vascular damage in children with Henoch Schonlein purpura nephritis (HSPN).

METHODS

The kidney pathological lesion of 78 biopsy-proven HSPN children was assessed with renal vascular damage, glomerular pathological damage, and tubulointerstitial pathological damage semi-quantitative points. The children were divided into 3 groups (light, medium, and heavy group) according to the renal vascular, glomerular, tubulointerstitial, glomerular and tubulointerstitial total pathological points. Blood and urine vascular endothelial growth factor concentration was detected by enzyme linked immunosorbent assay; the localized renal VEGF expression and microvessel density were detected by immunohistochemistry assay in the kidneys.

RESULTS

The semi-quantitative points of glomerular, tubulointerstitial, renal vascular, and glomerular and tubulointerstitial total points in different groups had significant difference (all P<0.01); the minor renal vascular damage, the higher light microvessel density, blood and kidney concentration of VEGF, and the VEGF excretion in the urine were also lower in different groups, and there were significant differences (all P<0.01). Glomerular points were positively related with tubular points, vascular points, kidney total score (r=0.596, 0.612, and 0.728; P<0.05, 0.05, and 0.01 respectively). Microvessel density was highly positively related with blood VEGF and renal VEGF, and negatively related with urine VEGF (r=0.601, 0.696, and -0.639, all P<0.01).

CONCLUSION

The urinary excretion of VEGF leads to the decrease of local kidney VEGF concentration resulting in the renal vascular injury, which may be the important reason for renal vascular damage and pathology chronic progress in HSPN children.

[Expression of vascular endothelial growth factor is related to microvessel injury of renal interstitium in children with Henoch Schönlein purpura nephritis]

OBJECTIVE

To investigate the relationship between vascular endothelial growth factor (VEGF) expression and microvessel injury of renal interstitium in children with Henoch-Schönlein purpura nephritis (HSPN).

METHODS

Thirty-two children with HSPN and who had not received glucocorticoid or immunodepressants treatment before hospitalization were enrolled. Five children undergoing nephrectomy due to renal trauma were used as the control group. Renal samples were stained by hematoxylin and eosin and renal pathological changes were evaluated semi-quantitatively. CD34 and VEGF expression was detected by immunohistochemistry. CD34 was used as the marker for endothelial cells of renal microvessels. The microvessel density (MVD) was calculated by CD34 immunostaining.

RESULTS

Compared with the control and the renal pathological grade II HSPN groups, MVD in the grade III and above HSPN groups decreased significantly, with an obvious reduction in MVD with the increased renal pathological grade (p<0.05). The renal microvessel score in the grades IIIa, IIIb, IV, and V HSPN groups decreased obviously compared with that in the control group. The renal microvessel score decreased with the increased renal pathological grade (p<0.05). VEGF expression in the grade II HSPN group was higher (p<0.05), while that in the grades IV and V HSPN group was lower than that in the control group (p<0.05). VEGF expression in the HSPN group showed a significant reduction with the increased renal pathological grade (p<0.05). There was a positive correlation between VEGF expression and MVD in renal tissue in the HSPN group (r=0.935, p<0.01).

CONCLUSIONS

The decreased expression of VEGF may be responsible for the renal pathological damage and microvessel injury in HSPN.

Inverse temporal changes of lipoxin A4 and leukotrienes in children with Henoch-Schönlein purpura

The pathogenesis of Henoch-Schönlein purpura (HSP) is not clearly understood. It remains unclear how changes of lipoxin A(4) (LXA(4)) that acts as a "braking signal" in inflammatory process occur in patients with HSP. In this study, we determined the temporal changes of blood and urinary LXA(4), Leukotriene (LT)B(4) and urinary LTE(4) in 49 children with HSP. Inverse temporal changes between gradually increased blood and urinary LXA(4) and gradually decreased blood and urinary LTB(4) and urinary LTE(4) were found in patients with HSP. Furthermore, both 15-S-hydroxyeicosatetraenoic acid and LXA(4) inhibited the LTB(4)-induced chemotaxis of leukocytes and release of LTB(4) from leukocytes obtained from the patients in the active phase of HSP. In 22 children with HSP nephritis, concordant with the gradually increased severity of mesangial proliferation and proteinuria, the glomerular expressions of 15-lipoxygenase and the levels of urinary LXA(4) gradually decreased and the glomerular expressions of LTC(4) synthase and the urinary LTE(4) and LTB(4) gradually increased. The levels of blood and urinary LXA(4) in patients with HSP nephritis were lower than those in patients with purpura alone in early resolution of HSP. The levels of blood and urinary LTB(4) and urinary LTE(4) in the patients with HSP nephritis were higher than those in patients with purpura alone in early resolution of HSP. There was positive correlation between blood LTB(4) and serum C-reactive protein in 49 children with HSP. These data suggest that LTs may play a proinflammatory and profibrotic role in the pathogenesis of HSP, and insufficiency of LXA(4) may be responsible for the patients with HSP whose illness become more serious.

[Relationship between leukotrienes and clinical, pathological features of Henoch-Schoenlein purpura nephritis in children]

OBJECTIVE

To investigate the role of leukotrienes (LTs) in the progress of children's Henoch-Schoenlein purpura (HSP) nephritis (HSPN), and to provide an experimental basis for clinical application of leukotrienes antagonists in treatment of HSPN.

METHODS

The serum and urine samples were collected from 34 patients with HSPN 18 of them received renal biopsy, 27 cases with HSP and 16 healthy children as control. The level of LTB4 in the serum and urine was tested by enzyme-linked immunosorbent assay (ELISA) and LTE4 in urine in each group by enzyme immunoassay (EIA). The extent of expression of LTC4 synthase was detected by indirect immune fluorescence (IIF) in the renal tissue of 18 HSPN cases who received renal needle biopsy. Meanwhile, 3 cases with thin basement membrane nephropathy (TBMN) and 4 cases with simple hematuria were enrolled as controls. The results of pathological examination of the 4 cases with simple hematuria was normal by light microscope or electron microscope. At the same time, total urine protein in 24 hours was determined in 24 HSPN patients.

RESULT

(1) The level of serum and urinary LTB4 in the children with HSPN was (1164.33 +/- 300.28) ng/L and (841.19 +/- 115.23) ng/L, respectively. The level of serum and urinary LTB4 in those with HSP was (559.60 +/- 180.23) ng/L and (574.42 +/- 101.17) ng/L, respectively. The level of serum and urinary LTB4 in the control group was (211.95 +/- 67.72) ng/L and (227.33 +/- 76.12) ng/L, respectively. There was significant difference in the LTB4 level between HSPN group and HSP group (P < 0.01) while there was statistically significant difference in the LTB4 level between HSPN group and control group (P < 0.01). The urinary LTE4 was (1252.31 +/- 251.62) ng/L, (805.93 +/- 185.52) ng/L and (149.51 +/- 33.66) ng/L for HSPN group, HSP group and control group, respectively, and the differences were significant (P < 0.01). (2) The increase of serum and urinary LTB4 and urinary LTE4 was closely relative to the severity of histopathological changes. (3) Serum and urinary LTB4, urinary LTE4 increased in parallel to the enhancement of urine protein in HSPN patients (P < 0.01 or P < 0.05). (4) Markedly significant difference of LTC4 synthase by IIF existed between HSPN groups and control group.

CONCLUSION

LTs can promote the progress of children's HSPN. There is a close relationship between LTs expression in renal tissues, the pathological severity of HSPN and proteinuria.

Neutrophil activation, protein oxidation and ceruloplasmin levels in children with Henoch-Schönlein purpura

The aim of this study was to investigate the role of neutrophil activation, protein oxidation and ceruloplasmin (CLP) in the pathogenesis of Henoch-Schönlein purpura (HSP), which has not been investigated previously. Serum activities of myeloperoxidase (MPO) and arylesterase (ARYL) and levels of free thiol groups, CLP and total oxidant status (TOS) were measured in 29 children with HSP at the onset of the disease and during remission in comparison with 30 healthy subjects. Patients at active stage had significantly higher MPO activity (391+/-277 vs. 155+/-154 U/l, P<0.001), higher CLP (832+/-120 vs. 682+/-114 mg/dl, P<0.001) and TOS values (20.7+/-11.8 vs. 7.5+/-2.8 micromol H2O2/l, P<0.001) than the controls, respectively. Patients had significantly lower ARYL activity (158x10(3)+/-39x10(3) vs. 187x10(3)+/-46x10(3) U/l, P<0.001) and lower free thiol levels (234+/-48 vs. 279+/-26 micromol/l, P<0.001) than the controls, respectively. Significantly positive correlations were found between TOS and MPO (r=0.437, P=0.018) and TOS and CLP (r=0.409, P=0.028) at disease onset, whereas a negative correlation was found between MPO and thiol (r=-0.597, P=0.001) during remission. In conclusion, protein oxidation and neutrophil activation may play important roles in the pathogenesis of HSP. Further research is required to understand the potential linkage between oxidant stress and complications and to develop therapeutic strategies in HSP.

[Role of mast cells in the development of renal interstitial fibrosis in children with Henoch-Schonlein purpura nephritis]

OBJECTIVE

To investigate the role of mast cells in the development of renal interstitial fibrosis in children with Henoch-Schonlein purpura nephritis (HSPN) and possible mechanisms.

METHODS

Paraffin-embedded renal biopsy tissue sections from 20 children with HSPN were examined for the levels of tryptase-beta and transforming growth factor-beta1 (TGF-beta1) by immunohistochemical staining. Mast cells were counted by toluidine blue staining. Masson staining was used to assess the level of renal interstitial fibrosis and renal histopathological scores. Normal renal tissue sections from 5 nephrectomized children for nephroma were used as control group.

RESULTS

The percentages of positive tryptase-beta cellsand mast cells and the TGF-beta1 expression in the HSPN group were significantly higher than those in the control group (P < 0.05). The percentages of positive tryptase-beta cells and mast cells and the TGF-beta1 expression in renal tissue were positively correlated with the glomeruli histopathological score (r =0.940, 0.920, 0.937, respectively; P < 0.05) and were also positively correlated with the histopathological score of renal interstitium (r=0.903, 0.859, 0.948, respectively; P < 0.05). The level of renal interstitial fibrosis was positively correlated with the percentages of positive tryptase-beta cells and mast cells and the expression of TGF-beta1 (r =0.790, 0.766, 0.858, respectively; P < 0.05). There was a positive correlation between the percentages of positive tryptase-beta cells and mast cells (r =0.941, P < 0.05), between the percentage of positive tryptase-beta cells and the TGF-beta1 expression (r =0.897, P < 0.05) and between the percentage of positive mast cells and the TGF-beta1 expression (r=0.942, P < 0.05).

CONCLUSIONS

Tubulointerstitial mast cell infiltration is associated with the development of renal interstitial fibrosis in children with HSPN. Mast cells together with TGF-beta1 and mast cell-derived tryptase-beta may be involved in the development of the renal interstitial fibrosis in HSPN.

[Role of mast cells and eosinophil cationic protein in the pathogenesis of Henoch-Schonlein purpura nephritis]

OBJECTIVE

Mast cells and eosinophil have been found to play important roles not only in the development of anaphylactic inflammation but also in the chronic progression of organ reconstruction. But their role in the pathogenesis of Henoch-Schonlein purpura nephritis (HSPN) has not been fully understood. The present study was conducted to observe the serum levels of eosinophil cationic protein (ECP) and renal infiltration of mast cells in HSPN in order to elucidate their role in the development and progression of HSPN in children.

METHODS

The serum ECP levels were determined in 46 children with HSPN by fluoro-enzyme immunoassay (FEIA) using the Pharmacia CAP System. The distribution of mast cells infiltration was detected by immuno-enzyme-histological staining of tryptase (a marker for mast cell activation) and their relation with pathological changes was analyzed in 32 children with HSPN.

RESULTS

The serum ECP levels were 16.3 +/- 6.5 microg/L in the active stage of HSPN, significantly higher than that in remission stage (3.9 +/- 1.4 microg/L, P < 0.01) and that in control group (3.1 +/- 1.7 microg/L, P < 0.01). The number of mast cells in renal interstitium was 4.4 +/- 2.4 cells/mm2 in normal kidney, and significantly increased to 27.2 +/- 19.2 cells/mm2 in children with HSPN ISKDC grade II (P < 0.01) and 42.1 +/- 16.4 cells/mm2 in grade III (P < 0.05 when compared with grade II), 77.9 +/- 15.0 cells/mm2 in grade IV (P < 0.05 when compared with grade III).

CONCLUSION

The serum ECP level could reflect disease activity of HSPN, and mast cell infiltration in kidney correlated significantly with renal histological severity in HSPN. Mast cells and eosinophil may play important roles in the development and progression of HSPN.

Abundance of the long pentraxin PTX3 at sites of leukocytoclastic lesions in patients with small-vessel vasculitis

OBJECTIVE

The prototypical tissue pentraxin PTX3 inhibits phagocytosis of late apoptotic polymorphonuclear leukocytes (PMNs) by macrophages. Levels of PTX3 parallel disease activity in small-vessel vasculitis. Small-vessel vasculitis is often characterized by leukocytoclasia, a phenomenon of accumulation of nuclear remnants from unscavenged PMNs in or near the vessel wall. We therefore hypothesized that PTX3 accumulates at sites of leukocytoclastic vasculitis and, as such, is a key factor for the induction of leukocytoclasis.

METHODS

We examined skin biopsy samples from 13 patients with small-vessel vasculitis and from 4 healthy and 3 inflammatory skin disease controls. Biopsy tissues, characterized histopathologically as leukocytoclastic vasculitis, were studied for the presence of PTX3 using rabbit anti-PTX3 polyclonal antibodies. Sections were scored morphometrically for leukocytoclastic infiltrates in conjunction with PTX3 staining. Morphometric scores were expressed as percentages of staining of the total tissue area.

RESULTS

Biopsy specimens from patients with leukocytoclastic vasculitis revealed an abundant up-regulation of PTX3 at sites of leukocytoclastic infiltrates. Significantly more PTX3 was found in tissues from the 13 patients with vasculitis (mean +/- SEM 48.9 +/- 6.1%) than in tissues from the 7 controls (4.5 +/- 2.7%) (P = 0.0003). PTX3 was localized around vessels, as well as spread diffusely throughout the tissue.

CONCLUSION

PTX3 is abundantly present at sites of leukocytoclastic infiltrates in patients with small-vessel vasculitis, but not in controls. Since PTX3 inhibits phagocytosis of late apoptotic PMNs by macrophages and is strongly up-regulated at sites of leukocytoclastic infiltration, PTX3 is a candidate factor in the phenomenon of leukocytoclasia in small-vessel vasculitis.

Clinical predictors of self-limited urinalysis abnormality in childhood Henoch-Schönlein purpura nephritis

BACKGROUND AND AIM

The majority of patients (85-95%) with Henoch-Schönlein purpura nephritis (HSPN) suffer from a prolonged course of urinalysis abnormality. We sought to identify favourable prognostic factors predicting a self-limited urinalysis abnormality within 1 y.

METHODS

Fifty-eight HSPN patients admitted to the University Hospital between 1990 and 2003 were retrospectively analysed. Detailed information on clinical and laboratory manifestations on admission and sequential follow-up clinics were recorded. The chi2 or Fisher's exact test were used for univariate analysis, and multiple logistic regression was used for multivariate analysis.

RESULTS

The study cohort included 31 boys and 27 girls, with a mean age of onset of 8.0+/-4.3 y and a median follow-up duration of 5.9 y (range 1 to 25). Of 58 patients, 39 (67.3%) had a self-limited urinalysis abnormality within 1 y. On multivariate analysis, onset age less than 9 (p=0.038), low-grade proteinuria (p=0.044) and interval between purpura onset and renal manifestations less than 2 wk (p=0.005) predicted self-resolved urinalysis abnormality within 1 y. With two or more predictive factors, the sensitivity for short-term course was 84.6%, the specificity was 73.7%, and the positive predictive value was 84.8%.

CONCLUSION

A small number of variables were important for detecting a favourable short-term course of urinalysis abnormality.

Role of mesangial fibrinogen deposition in the pathogenesis of crescentic Henoch-Schonlein nephritis in children

AIMS

To clarify the role of mesangial fibrinogen deposition in crescentic Henoch-Schönlein nephritis (HSN).

METHODS

A retrospective analysis of 21 children with HSN treated with immunosuppressants. Serial renal biopsies were performed before and after treatment. They were divided into two groups according to the immunofluorescent course of fibrinogen deposition: group I (n = 9), no or decreased deposition; group II (n = 12), persistent or increased deposition.

RESULTS

There were no differences between the two groups in renal manifestations or laboratory and histological findings at presentation. However, the activity index after immunosuppressive treatment was significantly decreased in group I (mean, 7.9 (SEM, 0.7) v 2.9 (0.4); p = 0.008) and unchanged in group II (mean, 6.8 (SEM, 0.3) v 6.0 (2.1)). The chronicity index was unchanged in group I, but increased in group II (mean, 0.8 (SEM, 0.3) v 1.8 (0.3); p = 0.02). Univariate analysis revealed that the only factor significantly related to persistent or increased fibrinogen deposition was age more than 9 years (p = 0.03). Furthermore, the intensity of fibrinogen deposition at the second biopsy correlated positively with the age at onset (R2= 0.306; p = 0.009) and changes in the percentage of crescents (post-treatment crescents (%) minus pretreatment crescents (%)) correlated positively with the intensity of fibrinogen deposition at the second biopsy (R2= 0.193; p = 0.046).

CONCLUSIONS

This study indicates that fibrinogen deposition has an important role to play in renal injury of crescentic HSN and reflects persistent severe histological activity.

Henoch-Schonlein nephritis

Henoch-Schonlein purpura is a clinical syndrome characterized by the association of skin, joint, and gastrointestinal symptoms. Henoch-Schonlein purpura is characterized by wide-spread vasculitis. Although the clinical symptoms of this disease are characteristic, the diagnosis is not always easy to establish because other forms of systemic vasculitis - mainly the microscopic form of periarteritis nodosa - may mimic the disease. In addition, in contrast to systemic lupus erythematosus, there are no biological tests that can identify Henoch-Schonlein purpura with certainty. Immunofluorescence microscopic techniques have made an important contribution to both the diagnosis and the study of the pathogenesis of the disease, particularly since they have demonstrated the presence of IgA deposits in the glomeruli and in the vessel walls. These findings not only confirmed the immunologic nature of the pathologic lesions but also drew attention to the remarkable similarity between Henoch-Schonlein purpura nephritis and IgA nephropathy.

Henoch-schonlein purpura associated with esophagus carcinoma and adenocarcinoma of the lung

Henoch-Schönlein purpura (HSP) is known to exist in association with a variety of malignant diseases including squamous and small cell lung cancer and hematological malignancies. We report the first cases of HSP associated with carcinoma of the esophagus and adenocarcinoma of the lung, respectively. We compare the main features of our patients with 23 previously published cases. We recommend that patients with HSP, especially men over 40 years of age, should undergo screening for occult neoplasia.

Combined antithrombin and protein C supplementation in meningococcal purpura fulminans: a pharmacokinetic study

PURPOSE

To document in patients with meningococcal purpura fulminans (PF), the effects of a combined supplementation with antithrombin (AT) and protein C (PC) plasma concentrates and to estimate the pharmacokinetics and dose requirements of each inhibitor.

DESIGN

Retrospective study of 15 patients. SETTING. One paediatric and one adult ICU in a university hospital.

INTERVENTIONS

In addition to standard intensive care, all patients received a 100 IU/kg loading dose of AT and PC concentrates, followed by a continuous infusion (AT: 100-150 IU.kg.day; PC: 100 IU.kg.day in adults, and 400 IU/kg in infants).

MEASUREMENTS

Clinical data, coagulation, and fibrinolysis parameters, AT and PC activities, and free protein S (PS) levels were sequentially measured. Restitution ratio, median increment after supplementation, and half-life of clearance from plasma were calculated for the two plasma substitutes. RESULTS. At admission, all patients had a severe decrease in AT, PC, and PS levels. The supplementation regimen induced a substantial increase in AT and PC activities, peaking at H18 and H48, respectively. The supplementation procedure did not modify free PS levels. The median values of AT and PC restitution ratio, increment in plasma activity observed after 100 IU/kg concentrate, and apparent half-life of clearance from plasma were 0.85 U.ml.U.kg and 0.59 U.ml.U.kg, 23% and 21%, 16 h and 6 h, respectively.

CONCLUSION

If AT and PC concentrates are to be given in fulminant meningococcemia, the doses of supplementation should be at least 150 IU/kg AT and 250 IU/kg PC as loading dose and 150 IU/kg AT and 200 IU/kg PC as daily maintenance therapy. Taking into account the individual variability in inhibitor deficiency and restitution ratio, repeated measurements of plasma levels are mandatory to obtain a patient-based adjustment of the supplementation.

Nitric oxide in Henoch-Schönlein purpura

OBJECTIVE

To assess the value of nitric oxide (NO) production on the disease activity in children with Henoch-Sch6nlein purpura (HSP) by measuring serum nitrate levels and urinary nitrate excretion as an indicator for NO production.

METHODS

The study group consisted of 25 patients and 20 healthy children. We measured serum nitrate, urinary excretion of nitrate, and CRP levels in the acute phase and after remission.

RESULTS

Serum nitrate levels in the acute phase of the disease were found to be increased compared to the remission phase (28.67 +/- 10.3 mmol/l. 14.16 +/- 2.02 mmol/l) (p < 0.001) and the control group (13.15 +/- 2.28 mmol/l) (p < 0.001). Urinary nitrate excretion in the acute phase of the patients (15.32 +/- 9 mmol/mg) was increased compared to that in the remission phase (8.26 +/- 4.3 mmol/mg) (p = 0.016) and in the control group (7.24 +/- 4.9 mmol/mg) (p < 0.01).

CONCLUSION

Serum NO and urinary nitrate excretion were found to be elevated in patients with HSP and this increase was associated with activation of the disease rather than its severity. These findings suggest a role for NO in the pathogenesis of HSP, but nitric oxide in HSP should be further studied in order to elucidate the pathophysiology of the disease.

Immunoglobulin A-associated lymphocytic vasculopathy: a clinicopathologic study of eight patients

INTRODUCTION

Cutaneous IgA-associated vasculitis can be a clue to Henoch-Schönlein purpura (HSP), which typically comprises renal and gastrointestinal tract disease and arthritis, whereby prominent and predominant IgA deposits within the cutaneous vasculature provoke a pustular leukocytoclastic vasculitis.

DESIGN

We describe eight patients with a novel expression of a cutaneous IgA vascular injury syndrome, namely a lymphoid vasculopathy which clinically and light microscopically resembled a pigmentary purpura (PP) in six, and correlate direct immunofluorescence (DIF) and clinical features to light microscopy.

RESULTS

Among associated diseases were prior viral infection, an HSP symptom complex, an undifferentiated connective tissue disease syndrome, lupus erythematosus profundus (LEP), Degos' disease and Berger's disease. Skin lesions comprised non-palpable petechial lesions involving lower extremities in all cases and also the upper extremities in two. A superficial perivascular lymphocytic infiltrate unaccompanied by vascular fibrin deposits was associated with prominent erythrocyte extravasation including into the epidermis. Mural and extravascular fibrin deposition was seen in one biopsy from a PP-like lesion and mural fibrinoid necrosis was seen in the cases of LEP and Degos' disease; in biopsies from these three cases, the presence of fibrin deposition warranted use of the appellation 'lymphocytic vasculitis'. In all patients, DIF showed prominent and predominant IgA deposits.

CONCLUSIONS

A non-necrotizing lymphocytic purpuric vascular reaction is one manifestation of vascular IgA deposition in the skin. A subpopulation of human lymphocytes bear surface Fc receptor and/or C3 receptors ('complement receptor lymphocytes') which can bind circulating immune complexes (ICs) or C3 generated via activation of the alternative complement cascade. Thus, circulating ICs are a potential pathogenic basis of this eruption, the histologic differential diagnosis of which is idiopathic PP and PP of drug or viral etiology.

Pattern of renal beta 1(alpha 1-alpha 6) integrins distribution in IgA nephropathy and Henoch-Schoenlein nephritis

Immunoperoxidase staining was carried out using monoclonal antibodies against integrins alpha 1 beta 1, alpha 2 beta 1, alpha 3 beta 1, alpha 4 beta 1, alpha 5 beta 1 and alpha 6 beta 1 on renal biopsy specimens from patients with IgA nephropathy (IgAN, n = 15) and Henoch-Schoenlein nephritis (HSN, n = 10). The basic pattern of glomerular and tubulointerstitial (alpha 1-beta 6)beta 1 integrin distribution was similar in both studied groups, however increase in mesangial alpha 1 beta 1 integrin immunoexpression in biopsies from HSN patients as compared to biopsies from IgAN patients was observed. There were no statistical differences in the intensity of tubulointerstitial (alpha 1-alpha 6)beta 1 integrins immunolabelling in renal tissue between IgAN and HSN patients. The similar pattern of distribution of beta 1 integrins in renal tissue in IgAN and HSN patients may support the hypothesis of common pathogenesis of IgAN and HSN. Upregulation of alpha 1 beta 1 integrin on mesangial regions in biopsy specimens in patients with HSN may be connected to the much more florid glomerular changes in renal tissue in this type of glomerulonephritis than in IgAN.

Klebsiella-induced purpura fulminans in a Nigerian child: case report and a review of literature

Purpura fulminans (PPF) is a very severe but rare acute thrombohaemorrhagic illness of infants and young children. It occurs mainly, in patients with either congenital or acquired deficiencies of proteins C and S and antithrombin III. Features of PPF include disseminated intravascular coagulopathy, symmetrical necrotic purpura and/or ecchymoses and symmetrical peripheral gangrene; digital and/ or limb(s) amputations and end-organ failure(s) may also occur. The case of a 3.5 year-old Nigerian girl, who developed PPF following Klebsiella-rhinoscleromatis septicaemia is reported to illustrate the seriousness of the disease and the need for early diagnosis and management.

Gene polymorphism in IL-1 receptor antagonist affects its production by monocytes in IgA nephropathy and Henoch-Schonlein nephritis

OBJECTIVE

To define the functional significance of IL-1 receptor antagonist (IL-1ra) gene polymorphism and to investigate, the production of IL-1ra by monocytes from individuals with different genotypes of IL-1.

METHODS

The genotype of IL-1ra was detected by polymerase chain reaction (PCR). Peripheral monocytes obtained from patients with immunoglobin A nephropathy (IgAN), Henoch-Schonlein purpura nephritis (HSPN) and normal subjects were matched in sex and age between the IL1RN-2 allele carriers and non-carriers. The secretion of IL-1ra, IL-1 alpha and IL-1 beta in the supernatant of GM-CSF (10 ng/ml) treated and untreated monocytes were measured by ELISA.

RESULTS

The secretion of IL-1ra by monocytes stimulated with GM-CSF was significantly higher in the IL1RN-2 allele non-carriers than those of carriers both in IgAN (21.55 +/- 3.08 vs 13.85 +/- 2.24 ng/ml, P < 0.001) and HSPN (23.72 +/- 6.68 vs 12.67 +/- 2.24 ng/ml, P < 0.01) as well as in normal controls (20.29 +/- 1.45 vs 10.51 +/- 2.3 ng/ml, P < 0.001). All showed no significant differences in monocyte secretion of IL-1 alpha and IL-1 beta by GM-CSF stimulation between the IL1RN-2 allele carriers and non-carriers.

CONCLUSIONS

These results indicate that a functional correlation of the IL1RN-2 allele and IL-1ra production is present in patients with IgAN and HSPN. This gene polymorphism control of IL-1ra production may contribute to the variety of clinical responses to inflammatory stimulation in individuals with different genotype of IL-1ra.

VCAM-1, ICAM-1, and E-selectin in IgA nephropathy and Schönlein-Henoch syndrome: differences between tissue expression and serum concentration

The tissue expressions of vascular cell adhesion molecule 1 (VCAM-1), intercellular adhesion molecule 1 (ICAM-1) and endothelial leukocyte adhesion molecule 1 (E-selectin-1) were investigated in biopsy specimens from 28 patients with different stages of IgA nephropathy (IgAN) and 20 patients with acute renal failure (ARF) or chronic renal diseases (amyloidosis, Alport's glomerulopathy) by immunohistochemistry. The results were compared with the serum levels of the three adhesion molecules. VCAM-1 expression was significantly increased on parietal/tubular epithelial cells in IgAN and ARF. Significantly elevated circulating VCAM-1 levels were measured in IgAN and amyloidosis, but did not correlate with renal function (creatinine clearance). Significantly increased glomerular endothelial/epithelial ICAM-1 expression was found in IgAN and ARF. Intense mesangial ICAM-1 expression was found in mild stages of IgAN and in Schönlein-Henoch syndrome. Circulating ICAM-1 was not significantly elevated in IgAN and different renal diseases. VCAM-1 and ICAM-1 expressions of interstitial infiltrating cells were significantly higher in severe than in mild IgAN and associated with an increased infiltration of inflammatory leukocytes. Patients with IgAN and different renal diseases had decreased mesangial and almost absent interstitial E-selectin expression as compared with controls. The circulating E-selectin levels were significantly elevated in ARF. In conclusion, the tissue expression of adhesion molecules in IgAN reflects a continuous inflammatory renal activity. However, only increased circulating VCAM-1 serum levels correlated significantly with the histological state of renal inflammation and could be used as a disease marker.

Disseminated intravascular coagulation and purpura fulminans secondary to infection

Infection is one of the commonest causes of disseminated intravascular coagulation (DIC). DIC is a complex disorder that results from an imbalance of the pro- and anticoagulant regulatory pathways. This chapter will explain the cellular and molecular basis of the disorder and consider the rationale behind current and experimental treatment strategies.

Large annular purpura and paraneoplastic purpura in a patient with Sjögren's syndrome and cervical cancer

We report a 79-year-old female with anaphylactoid purpura on her legs and unusual large annular purpura on the trunk. Histopathological characteristics of leukocytoclastic vasculitis were observed in the upper and middle dermis of both types of skin lesions. She was complicated by Sjögren's syndrome and advanced cervical cancer. The annular purpura spontaneously resolved in a week and did not recur. However, the anaphylactoid purpura relapsed more frequently and spread more widely following the elevation of her serum SCC antigen levels from the onset of purpura until her death. We consider that the characteristic annular configuration was caused by the complication of Sjögren's syndrome and that the recurrent anaphylactoid purpura indicated paraneoplastic vasculitis primarily caused by the tumor specific protein immune complexes. Complication by Sjögren's syndrome many also play a role in the development of allergic vasculitis.

[A study on the T-cell subsets and glucocorticoid receptor in children with anaphylactoid purpura]

To study the changes of T-cell subsets and glucocorticoid receptor (GCR) in children with anaphylactoid purpura. T-cell subsets and GCR were measured respectively by cytotoxicity assay and GCR radioligand-binding assay in peripheral blood lymphocytes from 35 children with anaphylactoid purpura and 35 normal children. The result showed that the average percentages of CD3+, CD4+ cell subtypes and the CD4+/CD3+ ratio were 46.03% +/- 9.40%, 31.06% +/- 6.80% and 1.23 +/- 0.33 respectively, and the GCR numbered 3060 +/- 2153 binding sites per cell in the study group, on the other hand, the average percentages of CD3+, CD4+ cell subtypes and the CD4+/CD3+ ratio were 53.11% +/- 5.40%, 35.01% +/- 4.41% and 1.52 +/- 0.26 respectively, and the GCR numbered 5210 +/- 1639 binding sites per cell in the control group. These indicate that and that patients with anaphylactoid purpura may have abnormal immunomodulations and decreased GCR numbers per cell, which may have effects on the immune dysfunctions in the pathogenesis of anaphylactoid purpura.

Henoch-Schönlein purpura and pulmonary hemorrhage: a report and literature review

Pulmonary hemorrhage, a rare complication of Henoch-Schönlein purpura (HSP) reported primarily in adults and adolescents, is associated with significant mortality. Although it has been suggested that pulmonary hemorrhage also occurs in children with HSP, the few cases reported lack a clear differentiation from pauci-immune vasculitis. We report a prepubertal child with HSP, pulmonary hemorrhage, and immunofluorescence-documented IgA deposits on renal biopsy. Aggressive supportive management and steroid therapy led to successful recovery. A review of the current literature is presented. Because other conditions clinically mimic HSP, appropriate serological studies and a kidney biopsy to confirm the diagnosis should be performed in severely affected patients with renal disease.

Expression of interferon-inducible Mx-proteins in patients with IgA nephropathy or Henoch-Schönlein purpura

Both viral infections and dysregulated cytokine synthesis have been implicated in the pathogenesis of immunoglobulin A nephropathy (IgAN) and Henoch-Schönlein purpura (HSP). Mx proteins are specifically induced by type I interferons (IFN-alpha, -beta, -omega) and are very sensitive in detecting, for example, virus-induced, in vivo production of IFN-alpha/-beta, because the biological half-life of Mx (approximately 3 days) markedly exceeds that of IFN-alpha/-beta (20 to 90 minutes). Mx concentrations in leukocytes were measured by enzyme-linked immunosorbent assay (ELISA) in 79 blood samples of 35 patients with IgAN and five with HSP. No patient showed symptoms of infections at the time of the examination. Compared with normal leukocyte Mx concentrations (<2 mU/1,000 leukocytes), only 3 of 79 samples of IgAN/HSP patients showed mildly elevated Mx concentrations (range, 2.2 to 3 mU/1,000 leukocytes). By contrast, patients with increased endogenous IFN production (lupus erythematosus) or patients treated with IFN-alpha2 showed leukocyte Mx concentrations of up to 35 mU/1,000 leukocytes. In patients with IgAN and HSP, leukocyte Mx concentrations were not correlated with various clinical parameters. Immunohistochemically, no renal Mx expression could be detected in eight renal biopsy specimens of patients with various stages of IgAN, whereas control specimens (skin of patients treated with IFN-alpha2) showed abundant cellular Mx expression. Furthermore, human mesangial cells in vitro showed marked Mx production after exposure to IFN-alpha or IFN-beta. We conclude that, in patients with IgAN/HSP, no evidence of an activation or dysregulation of the type I interferon system can be detected.

Molecular and genetic analysis of iron uptake proteins in the brazilian purpuric fever clone of Haemophilus influenzae biogroup aegyptius

Haemophilus influenzae biogroup aegyptius (H. aegyptius) is the etiological agent of Brazilian purpuric fever (BPF), a recently described pediatric disease that is often fatal. The vascular destruction that occurs in this disease is a distinctive trait, and little is known about the mechanism(s) of the overwhelming purpura fulminans that causes the high mortality associated with this pediatric infection. Iron is an essential micronutrient for nearly all living cells, and the mechanisms used by bacteria to acquire and internalize iron are often associated with virulence. Therefore, the focus of our studies is the molecular characterization of the iron uptake system used by H. aegyptius. Specifically, we are investigating the high-affinity transferrin binding proteins in the bacterial outer membrane, components of ABC transporter systems, and a possible regulatory mechanism for the genes encoding these proteins. A detailed understanding of the molecular nature of the regulatory genetic components and proteins involved in the acquisition of iron will broaden the knowledge of the pathogenesis of the disease caused by H. aegyptius and will also lead to a better understanding of the nature of other infections that affect the vascular system.

Abnormal IgA glycosylation in Henoch-Schönlein purpura restricted to patients with clinical nephritis

BACKGROUND

Glomerular deposition of IgA1 is a common feature of Henoch-Schönlein purpura, and is indistinguishable from that seen in IgA nephropathy. Serum IgA1 is abnormally O-glycosylated in IgA nephropathy, and this may contribute to mesangial IgA1 deposition and the development of glomerular injury. This altered O-glycosylation of IgA1 can be detected by its increased binding to the lectin Vicia villosa.

METHODS

To investigate whether IgA1 is abnormally glycosylated in Henoch-Schönlein purpura, the binding of Vicia villosa lectin to serum IgA1 was studied in the following subject groups: IgA nephropathy; adults and children with Henoch-Schönlein purpura and nephritis; children with clinically diagnosed Henoch-Schönlein purpura but no renal involvement; adults and children with non-IgA associated glomerulonephritis; and matched controls.

RESULTS

The abnormality of lectin binding seen in IgA nephropathy was also found in both adults and children with Henoch-Schönlein purpura with nephritis. However, the lectin binding of serum IgA1 from children with Henoch-Schönlein purpura lacking renal involvement did not differ from controls, and similarly, no abnormality of lectin binding was seen in patients with non-IgA associated glomerulonephritis.

CONCLUSIONS

These data indicate that the abnormality of IgA1 O-glycosylation seen in IgA nephropathy is also found in Henoch-Schönlein purpura, but only in those subjects with renal involvement, while IgA1 O-glycosylation is normal in patients with other forms of renal disease. These findings lend strong support to a role for altered IgA1 O-glycosylation in the pathogenesis of IgA-associated glomerular disease.

The role of cytokines in Henoch Schonlein purpura

Serum levels of tumor necrosis factor (TNF) and interleukin(IL-1) were studied in 20 HSP patients, in the acute phase and after remission, by ELISA technique. Skin biopsies obtained during the acute phase both from a lesion and from unaffected skin, as well as during remission, were immunostained for TNF, IL-1, and IL-6. The mean age of the patients was 9.8 (5-13). Mean serum TNF levels during the acute phase and remission were 14.0 +/- 8.9 pg/ml, and 6.8 +/- 2.4 pg/ml, respectively (p < 0.05). Serum TNF levels in patients with renal involvement (18.8 +/- 10.2 pg/ml) were significantly higher than in those without (10.8 +/- 6.5 pg/ml) (p < 0.05). Serum levels of IL-1 in the acute phase and remission were undetectable. All specimens showed leukocytoclastic vasculitis. Immunohistochemical studies revealed TNF, and a less intense IL-1 and IL-6 staining in the nucleated epidermal layer, with a granular, intracellular pattern. Staining was significantly increased in the affected skin during the acute phase. These results suggest that TNF, IL-1, and IL-6 may play a role as a mediator of inflammation in HSP.

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 microg/l) than in a control group (mean 4.6 +/- 0.7 microg/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.

Alterations in the O-linked glycosylation of IgA1 in children with Henoch-Schönlein purpura

OBJECTIVE

To examine O-linked glycosylation of serum IgA1 in children with acute Henoch-Schönlein purpura (HSP).

METHODS

The O-linked oligosaccharides of serum IgA1 from 28 children with acute HSP and 26 control children were examined by enzyme immunoassay using plant lectins with well defined carbohydrate binding specificities. The lectins included Artocarpus integrifolia (jacalin), Arachis hypogaea (peanut lectin), and Sambucus nigra (elderberry lectin). Jacalin binds to galactose-N-acetylgalactosamine (Gal-GalNAc). Jacalin interaction with this oligosaccharide is not influenced by the presence of sialic acid on the galactose moiety. Peanut lectin also interacts with Gal-GalNAc, but binding is inhibited if the galactose residue is sialylated. Elderberry lectin binds to N-acetylneuraminic acid (sialic acid).

RESULTS

There was no difference in the binding of jacalin to IgA1 from patients with HSP compared to controls (p = 0.5). The binding of peanut lectin to IgA1 was significantly higher in HSP compared to controls (p = 0.007). Since peanut lectin binding is inhibited by the presence of sialylated galactose, these results suggest diminished sialic content of the O-linked oligosaccharides of IgA1 in HSP compared to controls. Indeed, the binding of the sialic acid-specific elderberry lectin to IgA1 was significantly lower in HSP compared to controls (p = 0.004).

CONCLUSION

The O-linked oligosaccharides of serum IgA1 from children with acute HSP are deficient in salic acid compared to serum IgA1 from control children.

[Clinicopathological study of Henoch-Schönlein purpura nephritis with special reference to C3c deposits]

The aim of this study was to evaluate glomerular C3c deposits of Henoch-Schönlein purpura nephritis (HSPN) in children. Fifty-one patients aged 7-15 years (20 males and 31 females) were studied. On histological investigation, crescent formation seen under light microscopy and subepithelial electron dense deposits (EDD) under electron microscopy were found to be related to the degree of proteinuria and the duration of proteinuria and/or hematuria. A comparative clinicopathological study was performed on C3c-positive patients (n = 22) and C3c-negative patients (n = 25). Histological findings, such as crescent formation and subepithelial EDD, had no relation to glomerular C3c-deposits. At renal biopsy, C3c deposits were positive in 65 % of patients with heavy proteinuria ( > 100mg/kg/day), and in 30% of mild proteinuria patients ( < 50mg/kg/day). The difference between the two groups was statistically significant (p < 0.05). The duration of proteinuria and/or hematuria in C3c-positive patients had a tendency to persist in comparison with that in C3c-negative cases. Renal biopsies on many cases of C3c-negarive patients were performed following the lapse of three months, while the biopsies on patients showing global (+) C3c deposits (n = 15) were conducted within the three-month period. These results suggest that glomerular C3c deposits influence the clinical conditions of patients with HSPN, and complement activation is generated in the early stage of HSPN.

Intestinal IgA deposition in Henoch-Schönlein purpura with severe gastro-intestinal manifestations

In patients with Henoch-Schönlein purpura (HSP) presenting with severe gastro-intestinal (GI) symptoms, IgA deposition was studied in endoscopically obtained mucosal biopsies. A total number of 11 patients (male, 7; female, 4) were enrolled in this study; 7 patients underwent upper GI endoscopy and biopsy 1 underwent sigmoidoscopy and 3 underwent both. Upper GI endoscopy in each patient showed various mucosal changes including redness, petechiae, erosions, and ulcerations, most predominant in the second part of the duodenum. Sigmoidoscopy demonstrated no abnormality in two of four patients. Intestinal deposition of IgA was positive in 7 of 11 patients with HSP. Histological examination showed non-specific inflammation of varying degrees in each patient, but no small vessel vasculitis was observed. IgA deposits were seen in only 2 of 23 control subjects with various GI diseases. Positive rate of IgA deposition per patient was significantly higher in patients with HSP than in controls (P < 0.005).

CONCLUSION

IgA deposition in the GI tract, as in the skin and kidneys, is characteristic of HSP. Intestinal IgA deposition complements the diagnostic criteria of HSP.

Henoch-Schonlein nephritis associated with subacute thyroiditis

We present a 12-year-old boy who developed subacute thyroiditis during the course of rapidly progressive glomerulonephritis due to Henoch-Schonlein purpura (HSP) proven by clinical findings and percutaneous renal needle biopsy. The thyroid gland of the patient suddenly enlarged with mild tenderness while he was on steroid and dipyridamole therapy. Thyroid hormone levels revealed T3 0.31 ng/ml (nl: 0.52-1.75 ng ml), T4 2.53 ug/dl (nl: 4.8-12.8 ug/dl), free T3 0.80 pg/ml (nl: 2.14-5.34 pg/ml), free T4 0.2 ng/dl (nl: 0.73-1.95 ng/dl) and TSH 1.02 U/ml (nl: 0.36-3.25 U/ml). Antimicrosomal antibody was negative while antithyroglobulin antibody was slightly positive (1/80+). Hypoactivity with a spotty pattern was demonstrated by thyroid scanning. Serologically proven mumps infection was detected and may have been a triggering factor in the development of both HSP and subacute thyroiditis.

Intraglomerular deposition of intact cross-linked fibrin in IgA nephropathy and Henoch-Schönlein purpura nephritis

To investigate the significance of intraglomerular coagulation and fibrinolysis in IgA nephropathy (IgA-N) and Henoch-Schönlein purpura nephritis (HSPN), the distribution of intact cross-linked fibrin (XFb) modulated by plasmin activity was examined in 25 patients with IgA-N and in 12 with HSPN. In addition to the conventional method detecting fibrin-related antigen (FRA) with an antibody against fibrinogen, the enhanced intensity of immunoreactivity of cross-linked FRA (KL-FRA) using the monoclonal antibody DD3B6/22 after plasmin exposure was evaluated to assess intraglomerular deposition of intact XFb. Also, intraglomerular invasion of macrophages was detected using the monoclonal antibody KP1 against CD68. Sixteen of a total of 37 specimens (43%) showed increased intensity of XL-FRA staining after plasmin treatment which is considered to reflect the distribution of intact XFb. Increases in the intensity of XL-FRA staining were observed mainly in mesangium and partially along glomerular capillary loops and also in a few cases in the crescents. The incidence (67%) of increases in XL-FRA staining after plasmin exposure in HSPN specimens was significantly higher than that in IgA-N specimens (32%; p < 0.05). In the group positive for XL-FRA after plasmin exposure, the numbers of macrophages per glomerulus were significantly higher (n = 15; mean +/- SD = 1.6 +/- 0.9) than in the negative group (n = 6; 0.5 +/- 0.6; p < 0.01). In HSPN, the number of macrophages per glomerulus (n = 8; 1.9 +/- 1.0) was higher than that in IgA-N (n = 13; 0.9 +/- 0.9; p < 0.05). Based on these results, we conclude that XFb is often produced and distributed in intact form in the glomeruli both in IgA-N and HSPN, associated with a relatively low intraglomerular plasmin activity, and that intraglomerular coagulation may progress in accordance with macrophage infiltration, especially in HSPN.

High-dose immunoglobulin therapy for severe IgA nephropathy and Henoch-Schönlein purpura

OBJECTIVE

To determine if polyvalent IgG is promising therapy for severe IgG nephropathy.

DESIGN

Open prospective cohort study.

SETTING

Referral nephrology unit.

PATIENTS

11 adult patients with severe IgA nephropathy (9 who had idiopathic disease and 2 who had Henoch-Schönlein purpura) and indicators of poor prognosis.

INTERVENTION

Patients were given high-dose immunoglobulins (2 g/kg each month) for 3 successive months, followed by intramuscular immunoglobulins (preparation content, 16.5%; 0.35 mL/kg every 15 days) for another 6 months.

MEASUREMENTS

Histologic changes were analyzed by comparing pre- and post-therapy renal biopsy specimens blindly, using an activity index (14-point scale), a sclerosis index (10-point scale), and a semiquantitative immunofluorescence test of immune deposits. Proteinuria, hematuria, leukocyturia, enzymuria, and global renal function (creatinine and polyfructosan clearances) were evaluated before and after intervention.

RESULTS

Proteinuria (median level before intervention, 5.20 g/d; median level after intervention, 2.25 g/d), hematuria, and leukocyturia decreased substantially. The decrease in glomerular filtration rate was greatly slowed or stopped (median rate of decline in glomerular filtration before, -3.78 mL/min per month; after, 0 mL/min per month). The histologic index of activity (median index before, 5; after, 2) and the staining intensity of glomerular IgA and C3 deposits also decreased. Immunoglobulin therapy was well tolerated.

CONCLUSIONS

Immunoglobulin therapy may be effective in treating severe IgA nephropathy and protecting renal function. However, prospective controlled trials must confirm these preliminary results.

Adhesion molecules in experimental phacoanaphylactic endophthalmitis

Intraocular accumulation of inflammatory neutrophils is an important feature of experimental phacoanaphylactic endophthalmitis (EPE). Increasing evidence suggests that localization of neutrophils to the site of inflammation requires the participation of neutrophil and endothelial adhesion molecules. These studies were undertaken to determine if blocking of adhesion molecules on neutrophils (CD18) or endothelium (ELAM-1) could attenuate EPE in Lewis rats. Treatment of experimental animals with anti-CD18 or anti-ELAM-1 significantly suppressed intraocular neutrophil accumulation, retinal hemorrhage, and vasculitis, and attenuated retinal edema formation by 48% and 70%, respectively. These observations demonstrate that antibodies directed against adhesion molecules on the neutrophil (CD18) or the vascular endothelial cell (ELAM-1) exhibit potent anti-inflammatory effects, resulting in a striking amelioration of injury in EPE in rats.

Increased biosynthesis of vasoactive prostanoids in Schönlein-Henoch purpura

Schönlein-Henoch purpura (SHP) is an acute immune-mediated vasculitis characterized by infiltration of polymorphonuclear leukocytes into the vessel wall causing damage to the vascular endothelium by the release of proteolytic enzymes. The local inflammatory and thrombotic process may be regulated by increased biosynthesis of vasoactive prostanoids. We investigated the biosynthesis of thromboxane A2 (TxA2), a potent vasoconstrictor and platelet agonist, prostacyclin (PGI2), a vasodilator and platelet antagonist, and prostaglandin E2, a mediator of inflammation, in 14 children with SHP by physicochemical analysis of index metabolites in plasma and urine. TxA2 and PGI2 biosynthesis in the systemic circulation was significantly elevated in the acute phase of the disease and correlated with the degree of clinical symptoms. Recurrent episodes of the disease were associated with phasic increases of plasma and urinary TxA2 and PGI2 metabolites. Renal TxA2 formation was highest in two patients presenting with the nephrotic syndrome and extracapillary glomerulonephritis. Prostaglandin E2 biosynthesis in the systemic circulation was increased in the acute phase of the disease. The enhanced TxA2 formation is consistent with phasic platelet activation in SHP. The increased PGI2 biosynthesis reflects endothelial cell damage and may be a response of vascular endothelium to modulate platelet-vessel wall and leukocyte-vessel wall interactions. Increased prostaglandin E2 formation, which probably derives from activated polymorphonuclear leukocytes and macrophages, is thought to be related to the inflammatory process in SHP.