ROLE OF RENAL BIOPSY IN SILENT LUPUS NEPHRITIS M.E. Guerra 1, Y. Arce 2, M.M Díaz 3, P. Moya 4. J. Ballarín 3, F. Algaba 5 1 Department of Pathology. Central University Hospital of Asturias, Oviedo. Spain 2 Department of Pathology. Puigvert Foundation, Barcelona. Spain. 3 Department of Nephrology. Puigvert Foundation, Barcelona. Spain 4 Department of Rheumatology. Sant Pau Hospital, Barcelona. Spain. 5 Department of Pathology. Puigvert Foundation, Barcelona. Spain.

Systemic Lupus Erythematosus (SLE) is a multisystem autoimmune disease primarily affecting women of reproductive age. Kidney disease develops up to 60% of patients with SLE: 15-20% first clinical manifestation % had renal involvement at the time of lupus diagnosis. Important cause of morbility, even mortality. Goals for managing patients with lupus nephritis (LN): Early diagnosis Proper and prompt therapy to prevent irreversible damage without exposure of side effects of immunosupressors. INTRODUCTION

Renal Biopsy is essential to diagnose specific form of LN: Biological markers (serum levels C3, C4, anti-DNA): low sensitivity to predict activity disease and risk to develop new flares. Discrepancies between clinical presentation and pathologic findings. LN is not a static entity. Implies different prognosis and therapeutic approaches. Repeat biopsy in LN flares is a matter of controversy. Its role is still not defined after clinical remission. Daleboudt Gabrielle M. N. et al. Nephrol Dial Transplant (2009) Hsieh YP. Clin Nephrol 2012; 77: Seshan S. Arch Pathol Lab Med. 2009;133:233–48. INTRODUCTION

SILENT LUPUS NEPHRITIS (SLN) Zabaleta-Lanz M et al. Lupus 2003;12: Zabaleta-Lanz M et al. Inmunol 2004; 23: Zabaleta-Lanz M et al. Lupus 2006; 15: Moroni G. Am J Kidney Diseases.1999; 34:530–9. Yoo CW. Nephrol Dial Transplant. 2000;15:1604–8. Cavallo T. Am J Pathol1977;87:1–13 Ahmadian YS, Am J Dis Child 1972;123: 121 – 125.

OBJECTIVES Evaluate frequency of SLN in patients with at least one previous renal flare with histological confirmation, after induction/maintenance treatment, that achieved complete renal and clinical remission. Correlate complete renal remission with histological findings and compare them to those obseved in previous biopsy. Examine the influence of histological change in the therapeuthic decision.

Prospective and descriptive study. Review of patients diagnosed of SLE, as defined by American Rheumatism Association, that had LN biopsy-proven. Selection of patients who fulfill complete remission (CR) criteria for at least 2 years. 2nd biopsy is performed at this moment CR criteria: Proteinuria < 50mg/mmol creatinine. Normal renal function. Inactive urine sediment. Biopsies were categorized according to ISN/RPS classification protocol. Activity and chronicity index were determined according to the scoring system of Pollack et al., as modified by Austin et al. MATERIAL AND METHODS Weening JJ et al. J Am Soc Nephrol 2004; 15: Weening JJ et al. Kidney Int ;15:

Prospective and descriptive study. Review of patients diagnosed of SLE, as defined by American Rheumatism Association, that had LN biopsy-proven. Selection of patients who fulfill complete remission (CR) criteria for at least 2 years. 2nd biopsy is performed at this moment CR criteria: Proteinuria < 50mg/mmol creatinine Normal renal function. Inactive urine sediment. Biopsies were categorized according to ISN/RPS classification protocol. Activity and chronicity index were determined according to the scoring system of Pollack et al., as modified by Austin et al. MATERIAL AND METHODS Weening JJ et al. J Am Soc Nephrol 2004; 15: Weening JJ et al. Kidney Int ;15:

ACTIVITY AND CHRONICITY INDICES (NIH) Activity Index (0-24): - Endocapillary hypercellularity(0-3+) - Leucocyte infiltration(0-3+) - Subendothelial hyaline deposits (0-3+) - Fibrinoid necrosis / karyorrhexis: (0-3+) x 2 - Cellular crescents (0-3+) x 2 - Intersticial inflammation(0-3+) Chronicity Index (0-12): - Glomerular sclerosis(0-3+) - Fibrous crescents (0-3+) - Tubular atrophy (0-3+) - Intersticial fibrosis (0-3+) 0: Absent 1+: <25 % glomeruli affected 2+: % glomeruli affected 3+: > 50 % glomeruli affected Austin HA 3rd, Muenz LR, Joyce KM, Antonovych TA, Kullick ME, Klippel JH, Decker JL, Balow JE Kullick ME...Am J Med 1983 Sep;75(3): Austin HA 3rd, Muenz LR, Joyce KM, Antonovych TT, Balow JE. Kidney Int.1984 Apr;25(4):689-95

LUPUS NEPHRITIS CLASS I

LUPUS NEPHRITIS CLASS II

LUPUS NEPHRITIS CLASS III

LUPUS NEPHRITIS CLASS IV

LUPUS NEPHRITIS CLASS V

LUPUS NEPHRITIS CLASS VI

Collecting data Demographic Clinical (SLEDAI) Analitical Renal histology: International Society of Nephrology/Renal Pathology Society Classification of Lupus Nephritis 2004 (ISN/RPS). Activity and Chronicity Index. MATERIAL AND METHODS

RESULTS SexFFFFMFMFFF8 F 2M Age ,3 ± 12,6 SLEDAI (initial) ,7 ± 6,61

RENAL BIOPSY PRE-COMPLETE REMISSION Proteinuria (g/24h) 3,80,82,52,42,3 1,046,383,271,282,47 ± 1’66 Serum Creatinine (μmol/l) ,3 ± 19,91 Serum (g/L) Albumine 2221, ,140,639, ,531,5 ± 10,20 DNA % Positive C3 /C4 ↓/↓ N/↓ N/N ↓/↓N/↓↓/↓5 ↓/↓ Urine Sediment Positive SLEDAI ,6 ± 5,98 BIOPSY PRE-CR Class -Activity Index -Chronicity Index III+V (A/C) 0 3 III+V (A/C) 2 4 IV (G/A) 13 0 II 1 2 V+II 0 III (A/C) 4 IV S(A/C) 5 0 IV G-A 9 0 IV - II 0 3 II: 2 III:1 IV:4 III+V:2 3,4 1.6 INDUCTION TREATMENT CYC -- - MANTEINANCE TREATMENT MMF + TCR MMFAZA MMF + TCR MMF RESULTS

Proteinuria (g/24h) 0,260,10,170,250,430,350,15 0,110,2 0,21 ± 0,1 Serum Creatinine (μmol/l) ,2 ± 12,42 Serum Albumine (g/L) 48,342,543,24643,538,940,84542,74343,4 ± 2,97 DNA % positive C3 /C4 N/N N/↓N/NN/↓N/N N/↓ N/N 6 N/N Urine Sediment SLEDAI ,4 ± 2,11 BIOPSY AFTER CR: Class - Activity Index - Chronicity Index V03V03 V+II 2 3 V+II 0 1 II 0 2 V+II 1 II 2 0 II 0 II 0 1 II 0 II 0 2 II: 6 V: RENAL BIOPSY AFTER COMPLETE REMISSION RESULTS

CLASS PRE-CR - Activity Index - Chronicity Index III+V 0 3 III+V 2 4 IV 13 0 II 1 2 V+II 0 III 4 IV 5 0 IV 9 0 IV - II 0 3 CLASS AFTER CR - Activity Index - Chronicity Index V03V03 V+II 2 3 V+II 0 1 II 0 2 V+II 1 II 2 0 II 0 II 0 1 II 0 II 0 2 RESULTS 100% patients with SLN V II III IV

Biopsy Pre-CR Class III or IV o HISTOLOGICAL IMPROVEMENT 70% Biopsy after CR Class II

NO HISTOLOGICAL CHANGE 30% Biopsy Pre-CR Class II+V Biopsy after CR Class II+V

RESULTS Activity Index decreases CLASS PRE-CR -Activity Index - Chronicity Index III+V 0 3 III+V 2 4 IV 13 0 II 1 2 V+II 0 III 4 IV 5 0 IV 9 0 IV - II 0 3 CLASS AFTER CR --Activity Index - Chronicity Index V03V03 V+II 2 3 V+II 0 1 II 0 2 V+II 1 II 2 0 II 0 II 0 1 II 0 II 0 2 CI(CR) AICI AI(CR)

MANTEINANCE TREATMENT ===↓=↓↓↓↓= THERAPEUTIC OUTCOME CLASS AFTER CR: - Activity Index -Chronicity Index V03V03 V+II 2 3 V+II 0 1 II 0 2 V+II 1 II 2 0 II 0 II 0 1 II 0 II 0 2 INDUCTION TREATMENT CYC -- - MANTEINANCE TREATMENT MMF + TCR MMFAZA MMF + TCR MMF CLASS PRE-CR -Activity Index -Chronicity Index III+V 0 3 III+V 2 4 IV 13 0 II 1 2 V+II 0 III 4 IV 5 0 IV 9 0 IV - II 0 3

No patients achieve complete histological remission. Membranous pattern and mesangial proliferation remains, meanwhile endocapillary proliferation dissapears. Activity Index decreases and Chronicity Index remains the same. Renal biopsy in Complete Remission implicates a change in therapeutic decision in 50% of cases in our series. CONCLUSION Silent Lupus Nephritis is highly prevalent in patients with Systemic Lupus Erythematosus, being renal biopsy the gold standard for its diagnosis.

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