Incorporating Cystatin C to Predict Methotrexate Elimination in Patients with CNS Lymphoma and Suspicious Renal Function
Table 1
Laboratory values for patients longitudinally followed with serum creatinine and cystatin C during methotrexate administration for treatment of CNS lymphoma.
Day
SCr (mg/dL)
CysC (mg/L)
UOP (mL/kg/hr)a
eGFR-CG (mL/min)
eGFR CKD EPIcysC
eGFR CKD EPIcr-cysC
MTX (µmol/L)
mL/min/1.73 m2
mL/min
mL/min/1.73 m2
mL/min
Case 1 (51-year-old male, 172 cm, 72.7 kg, BSA 1.88 m2)
−1
0.4
1.81
5.46
>120
37
40
69
75
—
0
<0.4
—
4.48
>120
—
—
—
—
—
1
<0.4
—
5.36
>120
—
—
—
—
—
2
0.4
1.86
5.41
>120
35
38
68
74
0.44
3
<0.4
1.94
4.79
>120
33
36
66
72
0.18
4
<0.4
1.46
4.30
>120
49
53
81
88
0.16
5
<0.4
1.64
4.81
>120
42
46
75
82
0.13
6
<0.4
—
2.08
>120
—
—
—
—
0.12
7
0.2
1.63
2.15
>120
42
46
86
93
0.07
Case 2 (38-year-old male, 177 cm, 78.6 kg, BSA 1.97 m2)
−1
1.3
1.99
—
87
34
39
47
54
—
0
1.1
1.76
2.99
101
40
46
56
64
—
1
1.6
1.85
2.23
70
38
43
44
50
—
2
1.2
1.92
2.65
93
36
41
50
57
1.7
3
1.1
1.85
4.00
101
38
43
54
61
0.21
4
1.1
1.88
2.99
101
37
42
54
61
0.16
5
—
—
3.26
—
—
—
—
—
0.10
CKD EPI = Chronic Kidney Disease Epidemiology Collaborative; eGFR-CG = estimated GFR calculated from the Cockcroft-Gault equation; CysC = cystatin C; eGFR = estimated glomerular filtration rate; MTX = methotrexate; SCr = serum creatinine; athe daily fluid balance for Case 1 ranged from −5.1 L to +2.1 L and for Case 2 from −1.6 L to +2.4 L.
