Even mild cases of paediatric Henoch-Schönlein purpura nephritis show significant long-term proteinuria

IgA Vasculitis Associated With COVID-19

IgA vasculitis, also known as Henoch-Schonlein Purpura (HSP), is an inflammatory disorder of small blood vessels that can present with palpable purpura, arthralgias, abdominal pain, and kidney disease. It is most commonly found in pediatric patients after an inciting infection but has been seen across all ages and associated with certain drugs and vaccines. COVID-19 has been associated with various cutaneous manifestations, but HSP is a rarely reported one. We present a case of a 21-year-old female presenting with a petechial rash found to be seronegative IgA vasculitis presenting concurrently with dyspnea secondary to COVID-19. She was initially seen by an outside practitioner, tested negative for COVID, and was prescribed a course of oral prednisone. Shortly thereafter, she visited the ED for worsening shortness of breath and tested positive for COVID-19, for which she received Paxlovid. Biopsy after a visit to a dermatologist confirmed intramural IgA deposition on immunofluorescence, and she was tapered off prednisone and started on azathioprine.

Use of renin-angiotensin system inhibitors as initial therapy in children with Henoch-Schönlein purpura nephritis of moderate severity

BACKGROUND

Cases of Henoch-Schönlein purpura nephritis (HSPN) with moderate severity were demonstrated to achieve good prognosis after treatment with renin-angiotensin system (RAS) inhibitors. However, some patients required additional treatment for recurrence after remission. This study aimed to clarify the effect of RAS inhibitors in HSPN cases with moderate severity, including the proportion of cases with recurrence and their response to additional treatment.

METHODS

Among 126 patients diagnosed with HSPN between 1996 and 2019, 71 patients with clinicopathologically diagnosed HSPN of moderate severity, defined as ISKDC grade II-IIIa and serum albumin ≥ 2.5 g/dL, were investigated.

RESULTS

Proteinuria became negative after RAS inhibitor treatment alone in all 71 cases. However, 16 (22.5%) had recurrence. Eleven recurrent cases achieved negative proteinuria again following additional treatment. At the last follow-up (median 46.5 months; IQR, 23.2-98.2), 5 patients had persistent mild proteinuria; no patients had estimated glomerular filtration rate < 90 mL/min/1.73 m2. The pathological findings in all recurrent cases were ISKDC grade IIIa. The 16 recurrent cases had significantly higher proportions of glomeruli with global/segmental sclerosis (25.0 vs. 0%, P < 0.001) and tubular atrophy/interstitial fibrosis (37.5 vs. 12.7%, P =0.0 24) than 55 cases without recurrence.

CONCLUSIONS

Japanese childhood HSPN cases with moderate severity had good outcomes without need for corticosteroids or immunosuppressants, when prescribed RAS inhibitor treatment. Even in recurrent cases, abnormal proteinuria was transient, and prognosis was excellent. A higher resolution version of the Graphical abstract is available as Supplementary information.

Epidemiology of biopsy-proven Henoch–Schönlein purpura nephritis in children: A nationwide survey in Japan

Background

Little is known about the epidemiology of Henoch–Schönlein purpura nephritis (HSPN).

Methods

We conducted a nationwide epidemiological survey of Japanese children aged 1 to 15 years with HSPN. Children who were newly diagnosed with HSPN by biopsy between January 2013 and December 2015 were eligible for the survey to clarify the incidence of HSPN. We also conducted an institutional survey on kidney biopsy criteria and treatment protocols.

Results

A total of 353 of 412 institutions (85.7%) responded to the questionnaire. Of the 353 institutions, 174 reported to perform kidney biopsies at their institutions, and 563 children were diagnosed with HSPN. Considering the collection rate, the estimated incidence of biopsy-proven HSPN was 1.32 cases/100,000 children per year. The median age at biopsy was 7.0 years, and the male-to-female ratio was 1.2:1. The kidney biopsy criteria and treatment protocols for HSPN were as follows. Patients with acute kidney injury underwent biopsy at least one month after onset. For patients without kidney dysfunction, the timing for biopsy was determined by the amount of proteinuria. Regarding the treatment of HSPN, there were certain commonalities among the treatment protocols, they eventually differed depending on the institutions involved.

Conclusions

The incidence of biopsy-proven HSPN was 1.32 cases/100,000 children per year in Japan. The male-to-female ratio and date of diagnosis of HSPN were similar to those in previous studies. The kidney biopsy criteria and treatment protocols for HSPN varied among institutions. Further studies are warranted to establish an optimal treatment policy based on the prognosis.

To biopsy or not to biopsy: Henoch-Schönlein nephritis in children, a 5-year follow-up study

BACKGROUND

The prognosis of Henoch-Schönlein purpura (HSP), IgA vasculitis, depends on kidney involvement. There is no consensus on the initiation of treatment for HSP nephritis (HSPN). Some centres start treatment before performing a kidney biopsy (KB) while in others, treatment is dictated by the importance of the clinical, biological and histological signs. The aim of this study was to evaluate which of these two approaches is associated with a better kidney outcome at 5-year follow-up.

METHODS

This multicentre, retrospective, nonrandomised study included children treated for HSPN between 2006 and 2010 in a French paediatric nephrology unit. One group had an early KB at diagnosis (before starting treatment or in the 15 following days). In the second group, initial treatment was decided without performing a KB.

RESULTS

Among the 107 children included, 63.5% had an early KB at diagnosis. Follow-up at 5 years was completed in 44 children (28 KB at diagnosis, 16 no KB at diagnosis). Median urine protein/creatinine at 5 years was 2.5 mg/mmol in the early biopsy diagnosis group and 12.5 mg/mmol in the non-biopsy group. An antiproteinuric treatment was given, at 5 years, to 35.7% of the early biopsy at diagnosis children and in 62.5% of the non-biopsied children.

CONCLUSIONS

Children with early KB at diagnosis seem to have a better renal outcome at 5 years compared to those without an early biopsy at diagnosis or biopsied later. However, this is a small patient cohort and data are missing. Further work is needed to build consensual guidelines on the management of HSPN in children.

Association of kidney biopsy findings with short- and medium-term outcomes in children with moderate-to-severe IgA vasculitis nephritis

Assessing the initial severity of immunoglobulin A vasculitis nephritis (IgAV-N) is important due to its determining effect on kidney management and outcomes. This paper describes a multicentre paediatric cohort of IgAV-N patients and discusses relationships among clinical presentation, histological features, and kidney outcome. We retrospectively studied a cohort of 170 children with biopsy-proven IgAV-N, diagnosed between 2007 and 2017. One-quarter of the cohort (27%) presented with initial nephrotic syndrome (NS). Kidney biopsy revealed International Study of Kidney Disease (ISKDC) grade II or grade III in 83% of cases. Endocapillary proliferation was observed in 73% of patients, and chronic lesions were observed in 25%. Data analysis showed a significant association between NS at onset and endocapillary proliferation and cellular crescents. After a median follow-up of 21 months (IQR 12-39), 30% of patients had persistent proteinuria or decreased eGFR. At the end of follow-up, kidney impairment was more often observed in patients with NS at onset and those with cellular crescents and chronic lesions on initial kidney biopsy.Conclusion: This study highlights the relationship between the clinical and histological presentation of IgAV-N and the factors that affect kidney outcome. The ISKDC classification may be improved by including lesions that are more discriminating for disease severity and prognosis. What is Known: • Nephrotic syndrome (NS) or kidney failure at diagnosis and cellular crescents in more than 50% of the glomeruli are recognized as risk factors for poor kidney outcome in immunoglobulin A vasculitis nephritis (IgAV-N). • The reference histological classification of the International Study of Kidney Disease in Children (ISKDC) is primarily based on the presence and number of affected glomeruli (mesangial proliferation, cellular crescents). The updated Oxford classification, which emphasizes tubular atrophy and interstitial fibrosis, is also used to group pathological features of IgAV-N. Both classifications have limitations. What is New: • Medical treatment should not be postponed in patients with IgAV-N and NS until after biopsy, as NS at diagnosis is associated with initial histological severity and poorer kidney outcome. This proposal needs to be verified in further studies. • Endocapillary proliferation is associated with the initial severity of IgAV-N at diagnosis, while chronic glomerular changes and interstitial fibrosis are associated with poorer short- and medium-term kidney outcomes.

Management of IgA Vasculitis with Nephritis

Immunoglobulin A (IgA) vasculitis (IgAV), previously called Henoch-Schönlein purpura, is characterized by IgA-dominant immune deposits affecting small vessels and often involves the skin, gastrointestinal tract, joints, and kidneys. IgAV is the most common cause of systemic vasculitis in children. The long-term prognosis is dependent on renal involvement: IgAV with nephritis (IgAVN) can progress to renal failure. IgAVN is an inflammatory disease, providing a rationale for the use of corticosteroids. However, data supporting the use of corticosteroids in patients with established IgAVN of any severity remain limited, although most clinicians use them. Even in patients with severe forms of IgAVN, methylprednisolone pulses added to oral corticosteroids appears to improve renal outcomes. Considering the multihit hypothesis for the pathogenesis of IgAVN, involving many other immune agents, there is a strong rationale for the use of other immunosuppressive drugs in patients with IgAVN, including mycophenolic acid, cyclophosphamide, rituximab, calcineurin inhibitors, and complement inhibitors. Thus, these immunosuppressive treatments have also been evaluated in IgAVN, usually in corticosteroid-dependent or corticosteroid-resistant forms and in small retrospective studies. However, their efficacy has not been proven. Thus, the risk of progression to renal failure and the ongoing debate about the best management of IgAVN justifies the interest in investigating and identifying treatments that can potentially preserve renal function in patients with IgAVN. This review reports on the efficacy of the different drugs currently used for the treatment of IgAVN in adults and children.

Biopsy-proven Henoch-Schönlein purpura nephritis: a single center experience

BACKGROUND

Knowledge on normal progress and treatment of Henoch-Schönlein purpura nephritis (HSPN) is limited. This study reviews outcome, clinical, pathological, and therapeutic factors affecting the prognosis of HSPN patients.

METHODS

Forty-nine children with biopsy-confirmed HSPN diagnosed between September 2008 and 2018 were included. Demographics, clinical and laboratory data, treatment, and outcome were recorded at the time of biopsy, 3, 6, 12, and 24 months and at last visit. Clinical outcome was graded according to Meadow's criteria.

RESULTS

The median age at time of biopsy was 10.1 years (IQR:5.7) and female/male ratio 24/25. At presentation, 40.8% of patients had nonnephrotic proteinuria, 18.4% nephrotic syndrome (NS), 4.1% nephritic syndrome (NephrS), and 36.7% NephrS+NS. There were 11 patients with an estimated glomerular filtration rate below 90 ml/min/1.73 m². Biopsy specimens were classified according to International Study of Kidney Diseases in Children (ISKDC) and Oxford Classification MEST-C scoring systems. Forty-one patients received angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, 37 patients steroids, and 35 patients other immunosuppressive medications. At last visit, 24 patients had stage 1 chronic kidney disease (CKD), three stage 2 CKD, and two had stage 5 CKD. Neither clinical parameters nor ISKDC biopsy grade or treatment modalities effected the final outcome. The Oxford classification showed significantly increased segmental glomerulosclerosis in patients with unfavorable outcome. Favorable outcome was associated with shorter time from kidney involvement to biopsy and start of treatment.

CONCLUSION

A large proportion of patients continued to show signs of CKD at last follow-up while only a small proportion developed stage 5 CKD.

Risk factors associated with renal crescentic formation in pediatric Henoch-Schönlein purpura nephritis: a retrospective cohort study

BACKGROUND

The long-term prognosis of Henoch-Schönlein purpura (HSP) depends on the severity of renal involvement, and crescent formation is considered an important risk factor for poor prognosis of Henoch-Schönlein purpura nephritis (HSPN). The objective of this study was to evaluate factors affecting crescent formation in children with HSPN.

METHODS

Demographic factors, clinical characteristics, and laboratory data of children with HSPN with or without crescents were retrospectively analyzed. Univariate and multivariate logistic regression analyses were used to determine the risk factors of crescent formation in HSPN.

RESULTS

A total of 191 children with HSPN were enrolled in the study. There were 107 (56%) males and 84 (44%) females, with a median age of 7 years (range: 2 years-15 years). International Study of Kidney Disease in Children (ISKDC) grading was used to divide subjects into two groups: those without glomerular crescent formation (ISKDC grades I-II, n = 146 cases) and those with glomerular crescent formation (ISKDC grades III-V, n = 45 cases). Logistic regression analysis showed that higher urinary white blood cell (WBC) count (OR = 3.300; 95% CI, 1.119-9.739; P = 0.0306) and higher urinary microalbumin/creatinine ratio (ACR) (OR = 25.053; 95% CI, 1.354-463.708; P = 0.0305) were independent risk factors for the formation of crescents in HSPN. The area under the receiver operating characteristic curve of urinary WBC and ACR were 0.753 and 0.698 respectively, with the Hosmer and Lemeshow goodness-of-fit test (P = 0.0669, P > 0.05).

CONCLUSION

These results suggest that higher urinary WBC count and ACR should be strictly monitored for children with HSPN. Adequate clinical intervention for these risk factors may limit or prevent renal crescent formation.

MiR-29b expression is altered in crescent formation of HSPN and accelerates Ang II-induced mesangial cell activation

BACKGROUND

MicroRNA-29b (miR-29b) has been suggested to possess pro-inflammatory activity, which can partially be explained by the repression of tumor necrosis factor alpha protein three antibody (TNFAIP3). Meanwhile, it also promotes thyroid cell proliferation via Smad signaling pathways. The present study aimed to elucidate the role of miR-29b in Henoch Schönlein purpura nephritis (HSPN) and its underlying molecular mechanism in angiotensin II (Ang II)-induced human glomerular mesangial cell (HGMC) activation.

METHODS

We evaluated miR-29b expression in 35 HSPN renal tissues based on crescent formation, glomerular sclerosis, interstitial fibrosis, thrombosis formation and capillary loop necrosis. Meanwhile, HGMCs were cultured, treated with Ang II and then transfected with LV-hsa-miR-29b-1 to induce miR-29b overexpression or LV-hsa-miR-29b-3p-inhibition to inhibit miR-29b expression. Finally, we examined the effects of miR-29b on cell proliferation and release of inflammatory mediators.

RESULTS

We observed that miR-29b expression was significantly higher in the crescent group than in the no crescent group. MiR-29b overexpression induced the release of intercellular adhesion molecule-1, interleukin-1β (IL-1β), IL-6, IL-8, the increase of CyclinA2, CyclinD1, and cell proliferation. It also could inhibit the expressions of TNFAIP3 and NF-kappa-B-repressing factor (NKRF). Correspondingly, miR-29b inhibition produced the opposite effects and increased the expression of TNFAIP3 and NKRF.

CONCLUSION

MiR-29b expression is altered in crescent formation of HSPN and accelerates Ang II-induced mesangial cell proliferation and release of inflammatory mediators.

Histological prognostic factors in children with Henoch-Schönlein purpura nephritis

BACKGROUND

The management of IgA vasculitis with nephritis (IgAVN) remains controversial because of the difficulty to identify prognostic factors. This study reports the prognosis of children with IgAVN in relation to histological parameters.

METHODS

All children with IgAVN diagnosed between 2000 and 2015 in three pediatric nephrology centers were included. The following histological parameters were analyzed: mesangial proliferation (MP), endocapillary proliferation (EP), crescents, active, or chronic tubular and interstitial lesions (TIa lesions/TIc lesions), and segmental glomerulosclerosis (GS). Clinical and biological data were collected at the time of renal biopsy. The primary endpoint was IgAVN remission defined as a proteinuria < 200 mg/l without renal failure.

RESULTS

One hundred fifty-nine children were included with a median age of 7.6 years. Acute glomerular or TI lesions including MP, EP, crescents, and TIa lesions were observed, respectively, in 81%, 86%, 49%, and 21% of patients. Chronic glomerular lesions including GS and TIc lesions were observed in 6 and 7% of patients. Median initial proteinuria was 330 mg/mmol, albuminemia 32 g/l, and eGFR 110 ml/min/1.73 m². One hundred twelve (70%) patients were in remission at the end of a median follow-up of 37.4 months. Chronic lesions were significantly associated with the absence of remission in multivariate analysis, whereas EP, crescents and TIa were not associated with a poor prognosis.

CONCLUSIONS

Of children with IgAVN, 30% present a persistent renal disease at the end of a 3-year follow-up. Chronic histological lesions, but not EP or crescents, are associated with a bad prognosis and must be evaluated in IgAVN histological classification.

Childhood IgA Vasculitis (Henoch Schonlein Purpura)-Advances and Knowledge Gaps

Immunoglobulin A vasculitis (IgAV; formerly Henoch Schonlein Purpura) is the most common form of childhood vasculitis. It can occur in any age and peaks around 4-6 years old. It demonstrates seasonal variation implicating a role for environmental triggers and geographical variation. The diagnosis is made clinically and 95% of patients will present with a rash, together with any from a triad of other systems-gastrointestinal, musculoskeletal, and renal. Most cases of IgAV in children have an excellent outcome. Treatment may be required during the acute phase for gastrointestinal involvement and renal involvement, termed IgAV nephritis (previously HSP nephritis), is the most serious long-term manifestation accounting for ~1-2% of all childhood end stage kidney disease (ESKD). It therefore requires a period of renal monitoring conducted for 6-12 months. Patients presenting with nephrotic and/or nephritic syndrome or whom develop significant persistent proteinuria should undergo a renal biopsy to evaluate the extent of renal inflammation and there are now international consensus guidelines that outline the indications for when to do this. At present there is no evidence to support the use of medications at the outset in all patients to prevent subsequent renal inflammation. Consensus management guidelines suggest using oral corticosteroids for milder disease, oral, or intravenous corticosteroids plus azathioprine or mycophenolate mofetil or intravenous cyclophosphamide for moderate disease and intravenous corticosteroids with cyclophosphamide for severe disease. Angiotensin system inhibitors act as adjunctive treatment for persisting proteinuria and frequently relapsing disease may necessitate the use of immunosuppressant agents. Renal outcomes in this disease have remained static over time and progress may be hindered due to many reasons, including the lack of reliable disease biomarkers and an absence of core outcome measures allowing for accurate comparison between studies. This review article summarizes the current evidence supporting the management of this condition highlighting recent findings and areas of unmet need. In order to improve the long term outcomes in this condition international research collaboration is urgently required.

Off-label use of tacrolimus in children with Henoch-Schönlein purpura nephritis: a pilot study

BACKGROUND

Tacrolimus is used off-label in the treatment of Henoch-Schönlein purpura nephritis (HSPN) in children, with limited evidence-based data. Based on clinical empirical experience and mechanism of action, tacrolimus might be promoted as treatment for childhood HSPN. The objectives of this pilot study were to assess its effectiveness and safety, and to explore the potential impact of CYP3A5 genotype.

METHODS

Children with HSPN receiving tacrolimus as empirical treatment were included in this prospective, observational study. Effectiveness was classified as complete remission, partial remission or non-response. General safety data analyses during and after study drug exposure included adverse events, reasons for discontinuation, deaths, laboratory data and vital signs. Trough concentration was determined using high-performance liquid chromatography with tandem mass spectrometry. Pharmacogenetic analysis was performed on the CYP3A5 gene.

RESULTS

A total of 20 patients with a mean age of 7.5 (SD 2.1) years participated in the whole process of the study. Twelve patients reached complete remission and eight patients reached partial remission at the end of 6-month treatment. No patients discontinued tacrolimus treatment due to adverse events, and no drug-related adverse events were shown to have a causal association with tacrolimus therapy. Dose-adjusted trough concentration was significantly higher in children with CYP3A5*1 allele as compared with patients with CYP3A5*3/*3 genotype (170.7±100.9 vs 79.8±47.4 (ng/mL)/(mg/kg)).

CONCLUSION

This pilot study showed that tacrolimus might be an effective and well-tolerated drug for the treatment of HSPN in children. CYP3A5 polymorphism had a significant impact on tacrolimus concentration.

Henoch-Schönlein purpura nephritis: initial risk factors and outcomes in a Latin American tertiary center

The objective of this study was to evaluate prevalence, initial risk factors, and outcomes in Henoch-Schönlein purpura nephritis (HSPN) patients in Latin America. Two hundred ninety-six patients (validated EULAR/PRINTO/PRES HSP criteria) were assessed by demographic data, clinical/laboratorial involvements, and treatments in the first 3 months after diagnosis. They were followed-up in a Latin American tertiary center and were divided in two groups: with and without nephritis. Persistent non-nephrotic proteinuria, nephrotic proteinuria, and acute/chronic kidney injury were also systematically evaluated at 1, 5, 10, and 15 years after diagnosis. HSPN was evidenced in 139/296 (47%) in the first 3 months. The median age at diagnosis was significantly higher in HSPN patients compared without renal involvement [6.6 (1.5-17.7) vs. 5.7 (0.9-13.5) years, p = 0.022]. The frequencies of persistent purpura (31 vs. 10%, p < 0.0001), recurrent abdominal pain (16 vs. 7%, p = 0.011), gastrointestinal bleeding (25 vs. 10%, p < 0.0001), and corticosteroid use (54 vs. 41%, p = 0.023) were significantly higher in the former group. Logistic regression demonstrated that the independent variables associated with HSNP were persistent purpura (OR = 3.601; 95% CI (1.605-8.079); p = 0.002) and gastrointestinal bleeding (OR = 2.991; 95% CI (1.245-7.183); p = 0.014). Further analysis of patients without HSPN in the first 3 months revealed that 29/118 (25%) had persistent non-nephrotic proteinuria and/or hematuria in 1 year, 19/61 (31%) in 5 years, 6/17 (35%) in 10 years and 4/6 (67%) in 15 years after diagnosis. None of them had chronic kidney injury or were submitted to renal replacement therapy. The present study observed HSPN in almost one half of patients in the first months of disease, and HSPN was associated with persistent purpura and gastrointestinal bleeding. One fourth of patients had nephritis only evidenced during follow-up without severe renal manifestations.

Clinical outcomes in children with Henoch-Schönlein purpura nephritis without crescents

BACKGROUND

Henoch-Schönlein purpura is the most common vasculitis in children. Its long-term prognosis depends on renal involvement. The management of Henoch-Schönlein purpura nephritis (HSPN) remains controversial. This study reports the prognosis of children with HSPN presenting with class 2 International Study of Kidney Disease in Children (ISKDC) nephritis.

METHODS

All children with HSPN class 2 diagnosed between 1995 and 2015 in four pediatric nephrology centers were included, and clinical and biological data were collected from the medical files. The primary endpoint was proteinuria remission defined as a proteinuria <200 mg/L.

RESULTS

Ninety-two children were included in the study with a median follow-up of 36 (6-120) months; 28% had nephrotic syndrome, 31% proteinuria >3 g/L, 52% proteinuria between 1 and 3 g/L, and 18% proteinuria <1 g/L. Forty-seven percent of patients received orally treatment with steroids alone, 37% received methylprednisolone pulses followed by steroids orally, 18% received no steroids. Although 85% reached remission during follow-up, 12% did not maintain complete remission over time so that only 75% remained in complete remission by the end of the follow-up. Univariate analysis found a higher likelihood of remission in patients with higher proteinuria at disease onset (p = 0.009). This trend was not found in the multivariate analysis after adjusting for treatments, as patients with higher proteinuria were most often treated with steroids.

CONCLUSION

Our study shows that one fourth of patients with HSPN class 2 remain proteinuric and thus carry the risk of developing chronic kidney disease over the long term. This finding, together with the better outcome of patients treated with steroids, is in favor of using high-dose steroids orally or IV in these patients.

Beneficial effects of creatine phosphate sodium for the treatment of Henoch-Schönlein purpura in patients with early renal damage detected using urinary kidney injury molecule-1 levels

Henoch-Schönlein purpura (HSP) is a small-vessel disease in children that is often accompanied by kidney damage. Despite many efforts to improve the early assessment of renal injury in HSP patients, effective markers are still lacking. In recent years, the relationship between kidney injury molecule-1 (KIM-1) and tubulointerstitial injury has drawn much attention, especially regarding the diagnostic potential of serum and urinary KIM-1 levels. However, the diagnostic value of KIM-1 for detecting urinary kidney injury in HSP patients is still elusive. Furthermore, the treatment of Henoch-Schönlein purpura nephritis (HSPN) relies on the clinician's experience without performing renal biopsy, so it is important to find an effective biomarker and therapy. In the present study, we investigated the diagnostic value of urinary KIM-1 for early renal injury in HSP patients enrolled in a prospective, single-center study. Urinary KIM-1 levels were measured in 27 patients with HSP, 32 patients with HSPN (21 HSPN patients had undergone renal biopsy), and 16 healthy donors, as normal controls. The HSPN patients were randomly divided to receive either routine therapy (n = 13) or routine treatment combined with creatine phosphate sodium (CP) (n = 19). Urinary KIM-1 levels were significantly greater in the HSP and HSPN groups than those in the healthy control group (P < 0.01), and were significantly greater in the HSPN group than in the HSP group (P < 0.01). The urinary KIM-1 levels decreased significantly after 10-14 days of treatment with CP compared with conventional therapy (P < 0.05).

CONCLUSION

Our results demonstrate the diagnostic value of KIM-1 and the therapeutic potential of CP for early renal damage in HSP patients.

WHAT IS KNOWN

Urine kidney injury molecule-1 (KIM-1) is a sensitive biomarker for tubulointerstitial injury. Henoch-Schonlein purpura (HSP) usually presents with renal damage.

WHAT IS NEW

Our results suggest that the urinary KIM-1 level is a sensitive and specific biomarker for the detection of early renal damage in HSP and may predict the severity of HSP and HSPN. The administration of creatine phosphate sodium (CP) may reduce urinary KIM-1 levels and thus correct the hypoxic condition of the kidney. Preconditioning with CP may also be a useful adjunct for preventing early renal damage in HSPN patients.