Kidney Week

Abstract: TH-PO0505

Treatment of IgAN According to Kidney Lesions: A Randomized Controlled Trial (TIGER Study)

Session Information

• Glomerular Diseases: Clinical, Outcomes, and Therapeutics Research - IgAN
  October 22, 2026 | Location: Exhibit Hall A, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Glomerular Diseases

• 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics

Authors

• El Karoui, Khalil, Hopital Tenon, Paris, Île-de-France, France

Khalil El Karoui, MD, PhD

• Maillard, Nicolas, CHU St Etienne, Saint Etienne, France

Nicolas Maillard, MD, PhD

• Karras, Alexandre, Hopital Europeen Georges Pompidou, Paris, Île-de-France, France

Alexandre Karras, MD, PhD

• Hummel, Aurelie, Institut Necker Enfants Malades, Paris, Île-de-France, France

Aurelie Hummel, MD

• Audard, Vincent, Henri Mondor Hospital Department of Nephrology, Creteil, France

Vincent Audard, MD, PhD

• Alamartine, Eric, CHU St Etienne, Saint Etienne, France

Eric Alamartine, MD, PhD

• Joly, Dominique A., Institut Necker Enfants Malades, Paris, Île-de-France, France

Dominique A. Joly, MD, PhD

• Elie, Caroline, Institut Necker Enfants Malades, Paris, Île-de-France, France

Caroline Elie, MD, PhD

Background

The benefit of systemic corticosteroids in IgA nephropathy (IgAN) remains debated, while the potential impact in steroid response of stratification based on renal lesions is unknown. In this study, we evaluated whether early steroid therapy improves outcomes in patients with recent biopsy-proven IgAN and high-risk lesions.

Methods

TIGER is a multicenter, randomized, open-label trial comparing early corticosteroid therapy plus optimized nephroprotection versus nephroprotection alone in adults with IgAN and severe histological lesions. Inclusion required proteinuria >0.75 g/g and ≥2 positive items on the Oxford MEST-C classification from a biopsy performed within 45 days. The primary endpoint was treatment failure at 24 months, defined as proteinuria >0.5 g/g, or >20% decline in eGFR, or loss of >10 ml/min/1.73m2, or kidney failure, or renal transplantation, or death.

Results

The expected number of inclusions (122) was not reached. Fifty-nine patients were analyzed (30 control (Ctrl), 29 experimental (Exp); males 71%, caucasian 71%). Baseline characteristics and renal lesions were comparable between both groups (median eGFR 52 vs 59 ml/min/1.73m2; proteinuria 1.3 vs 1.5 g/g in Ctrl and Exp groups). Among patients in the Ctrl group, 15/30 (50%) received rescue steroid therapy (because of persistent proteinuria after month 6). At 24 months, treatment failure occurred in 63% Ctrl (including Ctrl with rescue steroid therapy) versus 48% Exp patients (RR 0.76, 95% CI 0.48–1.21; p=0.25). Regarding secondary outcomes, at 6 months, failure occurred in 70%Ctrl versus 41% Exp (RR 0.59, 95% CI 0.36–0.97; p=0.036). Moreover, mean proteinuria at month 9 (a validated surrogate endpoint of long-term evolution) was 0.72 (SD 0.73) vs 0.40 (SD 0.34) g/g (p=0.013), in Ctrl and Exp groups. At 24 months, persistent proteinuria >0.5 g/g was less frequent in Exp group (31% vs 53%, p=0.10). Over the entire follow-up, fewer patients in the Exp group reached failure criteria at any time (93% vs 68%, p=0.01). Renal function remained stable in both groups.

Conclusion

Although underpowered and not statistically significant for the primary endpoint, early steroid therapy was associated with improved short-term outcomes and greater reduction in proteinuria, a validated surrogate of long-term prognosis. These findings suggest a potential benefit of early, lesion-guided immunosuppression in high-risk IgAN.