Hematuria duration does not predict kidney function at 1 year in ANCA-associated glomerulonephritis.
OBJECTIVE
Hematuria is considered a marker of active renal disease in ANCA-associated glomerulonephritis (ANCA-GN) with induction immunosuppression often continued until hematuria has resolved. We aim to determine whether longer hematuria duration is associated with lower estimated glomerular filtration rate (eGFR) at 1 year.


METHODS
We conducted a retrospective study of 55 patients with biopsy-proven ANCA-GN. Linear regression models were constructed to determine predictors of eGFR at 1 year. The primary exposure was hematuria (>5 rbc/hpf) duration, defined as <90 days vs. ≥ 90 days following renal biopsy. Covariates included age, gender, ANCA type, baseline eGFR, and baseline proteinuria.


RESULTS
Mean age at diagnosis was 58 years (53% male, 80% Caucasian, 38% PR3-ANCA, and 45% MPO-ANCA). At baseline, all patients had hematuria, 95% had proteinuria, and mean serum creatinine was 3.1 [standard deviation (SD) = 2.3]mg/dL. Overall, 93% were treated with steroids in combination with either cyclophosphamide or rituximab. Mean hematuria duration was 92 (SD = 77) days with 34 (62%) patients having hematuria resolution within 90 days. Older age and lower baseline eGFR were associated with lower eGFR at 1 year (p = 0.03 and p < 0.001, respectively). Hematuria resolution (<90 days vs. ≥ 90 days) was not predictive of eGFR at 1 year (p = 0.93).


CONCLUSIONS
In ANCA-GN, hematuria duration does not predict eGFR at 1 year. Our findings provide support that among individuals who are otherwise considered to be in clinical remission, the persistence of hematuria should not delay transition from induction to maintenance immunosuppression.
Division of Nephrology, Johns Hopkins Bayview Medical Center, The Johns Hopkins University School of Medicine, 301 Mason F. Lord Dr, Baltimore, MD 21224.
Teresa K
TK
Chen
Division of Nephrology, Johns Hopkins Bayview Medical Center, The Johns Hopkins University School of Medicine, 301 Mason F. Lord Dr, Baltimore, MD 21224.
Christine
C
Murakami
Division of Rheumatology, The Johns Hopkins University School of Medicine, Baltimore, MD.
Rebecca L
RL
Manno
Division of Nephrology, Johns Hopkins Bayview Medical Center, The Johns Hopkins University School of Medicine, 301 Mason F. Lord Dr, Baltimore, MD 21224. Electronic address: gduvura@jhmi.edu.
Duvuru
D
Geetha
D000328:Adult; D000368:Aged; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000502:physiology*; D001706:Biopsy; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology; D005921:Glomerulonephritis / Q000503:physiopathology*; D006417:Hematuria / Q000150:complications / Q000503:physiopathology*; D006801:Humans; D007668:Kidney / Q000473:pathology / Q000503:physiopathology*; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D013997:Time Factors
D019268:Antibodies, Antineutrophil Cytoplasmic
ANCA; Glomerulonephritis; Hematuria; Renal function