Unveiling IgA Nephropathy with Crescents: A Prognostic and Therapeutic Dilemma

Introduction: Limited data exists regarding the outcomes, clinical significance, and management strategies for IgA Nephropathy (IgAN) with crescents. The KDIGO 2021 guidelines assert that neither the presence nor the relative number of crescents should predict IgAN progression or dictate the use of immunosuppression. However, some uncontrolled studies suggest otherwise. We present a challenging clinical case that underscores the need for further discussion on this topic. Case Description: A 62-year-old Caucasian male presented with worsening shortness of breath and bilateral lower extremity edema over two weeks. Initial evaluation revealed a serum creatinine level of 6.4 mg/dL and nephrotic-range proteinuria, indicating severe renal impairment. His baseline eGFR was previously normal. Insufficient follow-up data necessitated a renal biopsy, which identified IgAN with 47% crescents, moderate interstitial fibrosis and tubular atrophy (30%), and a MEST-C score of M1, E1, S0, T1, C2. Refractory hyperkalemia required emergent hemodialysis, continued as outpatient therapy due to lack of renal function recovery. The patient was treated with prednisone, cyclophosphamide, and lisinopril. After six months, although still on hemodialysis, there was partial renal function improvement as evidenced by decreased proteinuria. A follow-up biopsy to assess disease progression is pending. Discussion: The KDIGO 2021 guidelines recommend that crescents on renal biopsy should not predict disease progression or influence immunosuppression choice in IgAN cases. Contrary evidence suggests the importance of crescents should not be overlooked. Our case indicates potential benefits of steroid-immunosuppression therapy, as demonstrated by partial renal function recovery within a short follow-up period. We propose that evaluating crescents alongside other MEST scores, clinical data, and novel biomarkers can facilitate a personalized therapeutic approach for patients with IgAN.