Cystatin C and cathepsin B in CSF from patients with inflammatory neurologic diseases.
BACKGROUND
In CSF, proteolytic enzymes are believed to have crucial roles in the initiation and progression of inflammatory neurologic diseases (IND). Cystatin C, a major cysteine protease inhibitor in CSF, is tightly bound to cathepsin B and H.


OBJECTIVE
To determine if cystatin C is involved in the disease process of IND, the authors measured the cystatin C concentration by ELISA method and cathepsin B and H activities in the CSF of patients with acute IND.


METHODS
Cystatin C concentration and cathepsin B and H activities were measured in CSF samples taken from patients during the acute phase of their disease. Subjects studied were 8 patients with Guillain-Barré syndrome (GBS), 5 with chronic inflammatory demyelinating polyneuropathy (CIDP), 12 with MS, 16 with aseptic meningitis, 15 with neurodegenerative diseases as disease controls, and 35 healthy controls.


RESULTS
A significant decrease in CSF cystatin C level was seen in the patients with GBS, CIDP, and MS compared to the control subjects. High cathepsin B activity, but not cathepsin H activity, was also observed in the patients with GBS, CIDP, and MS.


CONCLUSIONS
Cystatin C levels in CSF measured by ELISA may help the physician recognize GBS, CIDP, and MS. Decreased levels of cystatin C may be related to the high levels of cathepsin B activity seen in the CSF of patients with GBS, CIDP, and MS.
Nagai
A
A
Departments of Internal Medicine III, Shimane Medical University, Izumo, Japan. nagaia@shimane-med.ac.jp
Murakawa
Y
Y
Terashima
M
M
Shimode
K
K
Umegae
N
N
Takeuchi
H
H
Kobayashi
S
S
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002401:Cathepsin B / Q000134:cerebrospinal fluid*; D055316:Cystatin C; D015891:Cystatins / Q000134:cerebrospinal fluid*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D020275:Guillain-Barre Syndrome / Q000134:cerebrospinal fluid*; D006801:Humans; D015850:Interleukin-6 / Q000134:cerebrospinal fluid; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D009136:Muscular Dystrophies / Q000134:cerebrospinal fluid*; D020277:Polyradiculoneuropathy, Chronic Inflammatory Demyelinating / Q000134:cerebrospinal fluid*
C525030:CST3 protein, human; D055316:Cystatin C; D015891:Cystatins; D015850:Interleukin-6; D002401:Cathepsin B