Introduction
Materials and methods
Study design and population
GC < 7.5 mg, 6 mo (N = 76) | GC \(\ge \) 7.5 mg, 6 mo (N = 54) | P | |
---|---|---|---|
Diagnosis, N (%) | |||
Granulomatosis with polyangiitis | 42 (55) | 28 (52) | 0.701 |
Microscopic polyangiitis | 34 (45) | 26 (48) | 0.701 |
Female sex, N (%) | 38 (50) | 26 (48) | 0.835 |
BMI | 25.9 (18.3–44.1) | 26.0 (19.1–43.3) | 0.988 |
Age at diagnosis, median (range), years | 66 (19–82) | 65 (45–84) | 0.352 |
Comorbidities at disease onset, N (%) | |||
Hypertension | 43 (57) | 32 (59) | 0.742 |
Diabetes type 2 | 15 (20) | 9 (17) | 0.401 |
Myocardial infarction | 5 (7) | 3 (5) | 0.669 |
Heart failure | 4 (5) | 3 (5) | 0.876 |
Chronic kidney disease (CKD \(\ge \) 3a) | 14 (18) | 8 (15) | 0.392 |
Active malignoma | 1 (1) | 0 (0) | 0.901 |
ANCA ELISA or IIF, N (%) | |||
PR3 | 39 (51) | 27 (50) | 0.882 |
MPO | 32 (42) | 25 (46) | 0.771 |
Double positive | 5 (7) | 2 (4) | 0.474 |
Organ involvement, N (%) | |||
General symptoms | 57 (75) | 43 (80) | 0.537 |
Ears, nose, throat | 19 (25) | 14 (26) | 0.905 |
Kidney | 76 (100) | 54 (100) | 0.999 |
Lung | 39 (51) | 31 (57) | 0.492 |
Nerve system | 6 (8) | 9 (17) | 0.123 |
Organ systems involved, median (range) | 2 (1–5) | 3 (1–5) | 0.228 |
Follow-up time, median (range), mo | 51 (3–116) | 73 (4–144) | 0.127 |
BVAS at disease onset, median (range) | 16 (3–62) | 19 (8–33) | 0.106 |
Kidney function at disease onset | |||
Serum creatinine, median (range), mg/dl | 2.4 (0.7–10.6) | 3.0 (0.7–11.3) | 0.122 |
eGFR, median (range), ml/min/1.73 m2 | 26 (4–83) | 18 (7–92) | 0.124 |
Proteinuria, N (%) | 70 (92) | 51 (94) | 0.605 |
Hematuria, N (%) | 69 (91) | 52 (96) | 0.223 |
Dialysis at disease onset, N (%) | 10 (13) | 9 (17) | 0.577 |
Induction therapy | |||
Cumulative CYC dose, median (range), g | 3.0 (0.8–20.8) | 3.0 (0.5–6.0) | 0.183 |
Cumulative CYC dose/kg BW, median (range), mg | 39.9 (8.2–256.0) | 38.4 (7.6–84.2) | 0.256 |
Duration of CYC induction, median (range), we | 12 (2–26) | 12 (2–22) | 0.393 |
Steroid pulse therapy, N (%) | 60 (79) | 41 (76) | 0.683 |
Plasma exchange, N (%) | 13 (17) | 8 (15) | 0.727 |
Maintenance therapy | |||
Azathioprine, N (%) | 57 (75) | 34 (63) | 0.140 |
Mycophenolic acid, N (%) | 8 (11) | 8 (15) | 0.463 |
Exclusively steroids, N (%) | 11 (14) | 11 (20) | 0.377 |
Steroid dose at disease onset, median (range), mg | 60 (16–80) | 60 (24–80) | 0.484 |
Steroid dose after 3 months, median (range), mg | 12 (4–60) | 20 (12–60) | < 0.001 |
Steroid dose after 6 months, median (range), mg | 4 (0–8) | 10 (10–40) | < 0.001 |
Duration of maintenance therapy, median (range), mo | 35.5 (8–89) | 33.0 (9–86) | 0.929 |
Statistical methods
Results
Study population and disease characteristics
Impact of GC maintenance therapy on relapse rate and patient survival
GC < 7.5 mg, 6 mo (N = 76) | GC \(\ge \) 7.5 mg, 6 mo (N = 54) | P | |
---|---|---|---|
Relapse rate, N (%) | 29 (38) | 21 (39) | 0.933 |
Time to relapse, median (range) | 30 (1–80) | 27 (5–88) | 0.796 |
Refractory disease, N (%) | 3 (4) | 3 (6) | 0.667 |
Disease activity | |||
BVAS after 3 mo, mean (range) | 0 (0–18) | 0 (0–23) | 0.091 |
BVAS after 6 mo, mean (range) | 0 (0–8) | 0 (0–18) | 0.600 |
BVAS after 12 mo, mean (range) | 0 (0–17) | 0 (0–3) | 0.647 |
Kidney function | |||
Serum creatinine after 3 mo, median (range), mg/dl | 1.4 (0.7–5.6) | 1.6 (0.8–2.7) | 0.092 |
eGFR after 3 mo, median (range), ml/min/1.73 m2 | 42 (9–98) | 44 (19–89) | 0.073 |
Serum creatinine after 6 mo, median (range), mg/dl | 1.4 (0.7–5.3) | 1.5 (0.8–2.9) | 0.058 |
eGFR after 6 mo, median (range), ml/min/1.73 m2 | 45 (6–103) | 42 (17–87) | 0.073 |
Serum creatinine after 1 a, median (range), mg/dl | 1.3 (0.8–3.7) | 1.4 (0.8–3.6) | 0.090 |
eGFR after 1 a, median (range), ml/min/1.73 m2 | 50 (8–108) | 44 (22–88) | 0.220 |
Serum creatinine after 2 a, median (range), mg/dl | 1.2 (0.8–3.5) | 1.4 (0.8–2.1) | 0.140 |
eGFR after 2 a, median (range), ml/min/1.73 m2 | 53 (18–105) | 48 (9–83) | 0.321 |
Serum creatinine after 3 a, median (range), mg/dl | 1.2 (0.7–3.6) | 1.4 (0.7–4.1) | 0.711 |
eGFR after 3 a, median (range), ml/min/1.73 m2 | 55 (18–130) | 48 (10–92) | 0.605 |
Serum creatinine after 4 a, median (range), mg/dl | 1.1 (0.7–3.0) | 1.2 (0.7–3.1) | 0.531 |
eGFR after 4 a, median (range), ml/min/1.73 m2 | 59 (22–87) | 57 (24–97) | 0.568 |
ESKD, N (%) | 4 (5) | 6 (11) | 0.220 |
Infectious complications | |||
At least 1 infectious complication, N (%) | 31 (41) | 41 (76) | < 0.001 |
Infectious episodes per patient, mean (range) | 0.6 (0–7) | 1.7 (0–6) | < 0.001 |
Urinary tract infection, N (%) | 18 (24) | 25 (46) | 0.007 |
Pneumonia, N (%) | 12 (16) | 21 (39) | 0.003 |
Opportunistic pneumonia, N (%) | 2 (3) | 7 (13) | 0.022 |
Herpes virus infections, N (%) | 7 (9) | 10 (19) | 0.121 |
Sepsis, N (%) | 2 (3) | 9 (17) | 0.008 |
VDI after 1 year, mean (range) | 0.7 (0–3) | 1.4 (0–4) | 0.001 |
Death during follow-up, N (%) | 6 (8) | 8 (15) | 0.256 |
Death by infection, N (%) | 1 (1) | 5 (9) | 0.034 |
Impact of GC maintenance therapy on kidney function, infectious complications and irreversible physical damage
Variable | OR (95% CI) | P |
---|---|---|
Glucocorticoid dose after 6 months | 1.12 (1.02–1.21) | 0.034 |
Lung involvement | 0.49 (0.15–1.76) | 0.301 |
BVAS score after 3 months | 1.07 (0.93–1.25) | 0.253 |
GFR after 6 months | 0.97 (0.98–1.12) | 0.206 |