, The following members of the HSPrognostic group are listed alphabetically. Zahir Amoura (Pitié Salpêtrière Hospital, Paris) Vincent Audard (Henri Mondor's Hospital, Créteil) Sonia Azib

M. Bagot,

, Véronique Baudouin (Robert Debré's Hospital, Paris) Olivier Benveniste (Pitié Salpêtrière Hospital, Paris) Maud Bezier

C. Bloch-queyrat, Pitié Salpêtrière Hospital, Paris) Nathalie Bocquet (Necker's Hospital, Paris) Jean-Jacques Boffa (Tenon's Hospital, Paris) Jean-David Bouaziz

K. Bouchireb, Necker's Hospital, Paris) Emmanuelle Bourrat (Robert Debré's Hospital, Paris) Philippe Bouvier

K. Brochard, Pediatric Hospital, Toulouse) Guillaume Burda (Hospital of Bethune)

G. Bussone, Cochin's Hospital, Paris) Valérie Caudwell (Sud Francilien Hospital, Evry) Laure Champion (Bichat's Hospital

M. Jonathan and . Chemouny, Bichat's Hostpital, Paris) Gérard Cheron (Necker's Hospital, Paris) Florence Cordoliani

S. Decramer,

L. Dehen,

L. Dehoux,

M. Delahousse, Foch's Hospital, Suresnes) Mathilde de Menthon (Saint-Louis's Hospital Paris)

C. Demongeot,

A. Dossier, Bichat's Hospital, Paris) Claire Dossier (Robert Debré's Hospital, Paris) Eric Daugas (Bichat's Hospital, Paris) Monique Dehoux (Bichat's Hospital

O. Fain,

D. Farge,

M. Fila,

C. Fite, Bichat's Hospital, Paris) Martin Flamant (Bichat's Hospital, Paris) Héloise Flament (Bichat's Hospital

E. Funck-brentano,

S. Georgin-lavialle,

B. Godeau, Henri Mondor's Hospital, Créteil) Philippe Grimbert (Henri Mondor's Hospital, Créteil) Loïc Guillevin (Cochin's Hospital

M. Halabi-tawil,

I. Halphen, Necker's Hospital, Paris) Alexandre Karras (Georges Pompidou European Hospital, Paris) Theresa Kwon (Robert Debré's Hospital, Paris) Céline Lebas, Valenciennes) Nicolas Limal (Henri Mondor's Hospital

A. Maisin,

A. Mathian,

A. Mekinian,

J. Mercier, Robert Debré's Hospital, Paris) Fabrice Mihout (Tenon's Hospital, Paris) Gentiane Monsel

V. Pestre, Cochin's Hospital

M. Piram,

T. Quemeneur, Jean Bernard's Hospital, Valenciennes) Quentin Raimbourg (Bichat's Hospital

A. Raynaud-simon, Bichat's Hospital, Paris) Philippe Rémy (Henri Mondor's Hospital, Créteil) Jacqueline Rivet

A. Saussine-hickman,

A. Seidowsky, Assia Smail (Robert Debré's Hospital, Paris) Stéphanie Tellier (Pediatric Hospital, Toulouse) Eric Thervet (Georges Pompidou European Hospital, Paris) Leila Tricot (foch's Hospital, Suresnes) Philippe Vanhille (Jean Bernard's Hospital, Valenciennes) David Verhelst (Henri Duffaut's Hospital, Avignon) Laurence Vrigneaud, Amroise Paré's Hospital

A. Verhoeven, Bichat's Hospital

, Jérôme Verine (Saint-Louis's Hospital Paris)

, Emmanuelle Vidal-Petiot (Bichat's Hospital, Paris) Manuelle Viguier (Saint-Louis's Hospital Paris)

N. Vittoz, Sud Francilien Hospital, Evry) François Vrtovsnik (Bichat's Hospital

A. Audemard-verger, E. Pillebout, L. Guillevin, E. Thervet, and B. Terrier, IgA vasculitis (Henoch-Shonlein purpura) in adults: Diagnostic and therapeutic aspects, Autoimmun Rev, vol.14, p.25688001, 2015.
DOI : 10.1016/j.autrev.2015.02.003

R. Coppo, G. Mazzucco, L. Cagnoli, A. Lupo, and F. P. Schena, Long-term prognosis of Henoch-Schonlein nephritis in adults and children. Italian Group of Renal Immunopathology Collaborative Study on Henoch-Schonlein purpura, Nephrol Dial Transplant, vol.12, p.9394311, 1997.

E. Pillebout, E. Thervet, G. Hill, C. Alberti, P. Vanhille et al., Henoch-Schonlein Purpura in adults: outcome and prognostic factors, J Am Soc Nephrol, vol.13, p.11961015, 2002.
DOI : 10.1097/01.asn.0000013883.99976.22

URL : https://jasn.asnjournals.org/content/13/5/1271.full.pdf

F. T. Saulsbury, Clinical update: Henoch-Schonlein purpura, Lancet, vol.369, pp.976-978, 2007.

J. C. Davin and R. Coppo, Henoch-Schonlein purpura nephritis in children, Nat Rev Nephrol, vol.10, p.25072122, 2014.

Y. X. Pan, Q. Ye, W. X. Shao, S. Q. Shang, J. H. Mao et al., Relationship between immune parameters and organ involvement in children with Henoch-Schonlein purpura, PLoS One, vol.9, p.25514176, 2014.
DOI : 10.1371/journal.pone.0115261

URL : https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0115261&type=printable

A. C. Allen, F. R. Willis, T. J. Beattie, and J. Feehally, Abnormal IgA glycosylation in Henoch-Schonlein purpura restricted to patients with clinical nephritis, Nephrol Dial Transplant, vol.13, p.9568852, 1998.
DOI : 10.1093/ndt/13.4.930

URL : https://academic.oup.com/ndt/article-pdf/13/4/930/9896625/930.pdf

K. K. Lau, R. J. Wyatt, Z. Moldoveanu, M. Tomana, B. A. Julian et al., Serum levels of galactose-deficient IgA in children with IgA nephropathy and Henoch-Schonlein purpura, Pediatr Nephrol, vol.22, p.17943324, 2007.

A. Berthelot-l-jamin, D. Viglietti, J. M. Chemouny, H. Ayari, and P. Housset, Value of biomarkers for predicting IgA vasculitis nephritis outcome in an adult prospective cohort, Nephrol Dial Transplant, p.29126311, 2017.

S. Ozen, A. Pistorio, S. M. Iusan, A. Bakkaloglu, T. Herlin et al., EULAR/PRINTO/PRES criteria for Henoch-Schonlein purpura, childhood polyarteritis nodosa, childhood Wegener granulomatosis and childhood Takayasu arteritis: Ankara 2008. Part II: Final classification criteria, Ann Rheum Dis, vol.69, p.20413568, 2010.
DOI : 10.1136/ard.2009.116657

URL : https://ard.bmj.com/content/69/5/798.full.pdf

G. J. Schwartz, A. Munoz, M. F. Schneider, R. H. Mak, F. Kaskel et al., New equations to estimate GFR in children with CKD, J Am Soc Nephrol, vol.20, p.19158356, 2009.

T. Robert, L. Berthelot, A. Cambier, E. Rondeau, and R. C. Monteiro, Molecular Insights into the Pathogenesis of IgA Nephropathy, Trends Mol Med, vol.21, p.26614735, 2015.

Q. Ye, S. Q. Shang, A. M. Liu, T. Zhang, H. Q. Shen et al., Urinary Protein Levels and Urine Protein/Creatinine Ratios Could Probably Forecast the Pathological Classification of HSPN, PLoS One, vol.10, p.25996387, 2015.

A. Fretzayas, I. Sionti, M. Moustaki, and P. Nicolaidou, Clinical impact of altered immunoglobulin levels in Henoch-Schonlein purpura, Pediatr Int, vol.51, p.19400827, 2009.

J. C. Davin, G. Pierard, C. Dechenne, D. Grossman, J. Nagy et al., Possible pathogenic role of IgE in Henoch-Schonlein purpura, Pediatr Nephrol, vol.8, p.8018493, 1994.

F. T. Saulsbury, Increased serum IgD concentrations in children with Henoch-Schonlein purpura, Br J Rheumatol, vol.37, p.9651087, 1998.

S. Yuksel, M. Caglar, H. Evrengul, T. Becerir, E. Tepeli et al., Could serum pentraxin 3 levels and IgM deposition in skin biopsies predict subsequent renal involvement in children with HenochSchonlein purpura?, Pediatr Nephrol, vol.30, p.25543194, 2015.

A. A. Belli and E. Dervis, The correlation between cutaneous IgM deposition and renal involvement in adult patients with Henoch-Schonlein purpura, Eur J Dermatol, vol.24, p.24509447, 2014.

S. Takeuchi, Y. Soma, and T. Kawakami, IgM in lesional skin of adults with Henoch-Schonlein purpura is an indication of renal involvement, J Am Acad Dermatol, vol.63, p.20933302, 2010.

T. J. Poterucha, D. A. Wetter, J. P. Grande, L. E. Gibson, M. J. Camilleri et al., A retrospective comparison of skin and renal direct immunofluorescence findings in patients with glomerulonephritis in adult Henoch-Schonlein purpura, J Cutan Pathol, vol.41, p.25097917, 2014.

K. Kiryluk, Z. Moldoveanu, J. T. Sanders, T. M. Eison, H. Suzuki et al., Aberrant glycosylation of IgA1 is inherited in both pediatric IgA nephropathy and Henoch-Schonlein purpura nephritis, Kidney Int, vol.80, p.21326171, 2011.

J. Mestecky, M. Raska, B. A. Julian, A. G. Gharavi, M. B. Renfrow et al., IgA nephropathy: molecular mechanisms of the disease, Annu Rev Pathol, vol.8, p.23092188, 2013.

A. Blanco-quiros, C. Blanco, J. Alvarez, P. Solis, F. Conde et al., Anti-immunoglobulin antibodies in children with Schonlein-Henoch syndrome. Absence of serum anti-IgA antibodies, Eur J Pediatr, vol.153, p.8157014, 1994.

L. Berthelot, C. Papista, T. T. Maciel, M. Biarnes-pelicot, E. Tissandie et al., Transglutaminase is essential for IgA nephropathy development acting through IgA receptors, J Exp Med, vol.209, p.22451718, 2012.
URL : https://hal.archives-ouvertes.fr/hal-00903832

M. T. Vuong, M. Hahn-zoric, I. Gunnarsson, C. Van-kooten, L. Wramner et al., Association of soluble CD89 levels with disease progression but not susceptibility in IgA nephropathy, Kidney Int, vol.78, p.20811333, 2010.

L. Berthelot, T. Robert, V. Vuiblet, T. Tabary, A. Braconnier et al., Recurrent IgA nephropathy is predicted by altered glycosylated IgA, autoantibodies and soluble CD89 complexes, Kidney Int, vol.88, p.26061544, 2015.

K. Harada, Y. Akai, N. Kurumatani, M. Iwano, and Y. Saito, Prognostic value of urinary interleukin 6 in patients with IgA nephropathy: an 8-year follow-up study, Nephron, vol.92, p.12399627, 2002.

C. Y. Lin, Y. H. Yang, C. C. Lee, C. L. Huang, L. C. Wang et al., Thrombopoietin and interleukin-6 levels in Henoch-Schonlein purpura, J Microbiol Immunol Infect, vol.39, p.17164950, 2006.

S. Kimura, S. Takeuchi, Y. Soma, and T. Kawakami, Raised serum levels of interleukins 6 and 8 and antiphospholipid antibodies in an adult patient with Henoch-Schonlein purpura, Clin Exp Dermatol, vol.38, p.24073654, 2013.

H. J. Oh, S. V. Ahn, D. E. Yoo, S. J. Kim, D. H. Shin et al., Clinical outcomes, when matched at presentation, do not vary between adult-onset Henoch-Schonlein purpura nephritis and IgA nephropathy, Kidney Int, vol.82, p.22895518, 2012.
DOI : 10.1038/ki.2012.302

URL : https://doi.org/10.1038/ki.2012.302

N. Besbas, U. Saatci, S. Ruacan, S. Ozen, A. Sungur et al., The role of cytokines in Henoch Schonlein purpura, Scand J Rheumatol, vol.26, p.9433407, 1997.

D. Vecchio, G. C. Penza, R. Altomare, M. Piacente, L. Aceto et al., Cytokine pattern and endothelium damage markers in Henoch-Schonlein purpura, Immunopharmacol Immunotoxicol, vol.30, p.18668398, 2008.

K. El-karoui, A. Viau, O. Dellis, A. Bagattin, C. Nguyen et al., Endoplasmic reticulum stress drives proteinuria-induced kidney lesions via Lipocalin 2, Nat Commun, vol.7, 2016.

A. Viau, K. El-karoui, D. Laouari, M. Burtin, C. Nguyen et al., Lipocalin 2 is essential for chronic kidney disease progression in mice and humans, J Clin Invest, vol.120, p.20921623, 2010.

T. Chen, Y. H. Lu, W. J. Wang, C. Y. Bian, X. Y. Cheng et al., Elevated urinary levels of cystatin C and neutrophil gelatinase-associated lipocalin in Henoch-Schonlein purpura patients with renal involvement, PLoS One, vol.9, p.24963810, 2014.

Y. Du, L. Hou, J. Guo, T. Sun, X. Wang et al., Renal neutrophil gelatinase-associated lipocalin and kidney injury molecule-1 expression in children with acute kidney injury and Henoch-Schonlein purpura nephritis, Exp Ther Med, vol.7, p.24940398, 2014.