Krebs von den Lungen-6 (KL-6) in cerebrospinal fluid from neurosarcoidosis patients

Main Article Content

Silvia Bocci
Miriana D'Alessandro
Laura Bergantini
Alfonso Cerase
Monica Ulivelli
Paola Rottoli
Dalila Cavallaro
Sara Gangi
Elena Bargagli
Fabio Giannini


neurosarcoidosis, Krebs von den Lungen-6, cerebrospinal fluid


Background: Krebs von den Lungen-6 (KL-6) is a high molecular weight (MW) glycoprotein mainly secreted by type II pneumocytes because of lung damage or during regeneration. Neurosarcoidosis (NS), where sarcoid granulomas involve the nervous system, occurs in 5-20% of patients with sarcoidosis. No data is currently available on KL-6 in serum or CSF of NS patients. The present study compared KL-6 concentrations in serum and CSF of NS patients versus others with neurodegenerative (ND) or chronic inflammatory demyelinating (DM) diseases.

Materials and methods: Nine NS patients (mean age 46.2 years, range 16-61 years, M/F 5/4), nine patients with a chronic neurodegenerative disease (mean age 53.1 years, range 37-65 years, M/F 5/4) and nine patients with a chronic demyelinating disease (mean age 46.3 years, range 18-65 years, M/F 5/4) were retrospectively enrolled.

Results: Measurable CSF concentrations of KL-6 were detected in 7/9 NS patients but in no ND or DM patients. No significant differences in CSF concentrations of ACE were observed between the three groups (p=0.0819). In NS patients, CSF concentrations of KL-6 were directly correlated with CSF albumin index (r=0.98; p<0.0001), albumin (r=0.979, p=0.0001), IgG (r=0.928, p=0.0009) and total protein concentrations (r=0.945, p=0.0004).

Discussion: KL-6 is a high MW protein, under physiological conditions it is unlikely to cross the blood-brain barrier. We found KL-6 in CSF from NS and not from ND and DM patients. The finding sustains the specificity of changes in KL-6 in this granulomatous disease, suggesting it as a candidate biomarker for recognition of NS.



Download data is not yet available.
Abstract 276 | PDF Downloads 249


1. d’Alessandro M, Bergantini L, Cameli P, et al. Serum Concentrations of KL-6 in Patients with IPF and Lung Cancer and Serial Measurements of KL-6 in IPF Patients Treated with Antifibrotic Therapy. Cancers (Basel). 2021 Feb 9;13(4).
2. Fritz D, van de Beek D, Brouwer MC. Clinical features, treatment and outcome in neurosarcoidosis: systematic review and meta-analysis. BMC Neurol. 2016 Nov 15;16(1):220.
3. Bathla G, Singh AK, Policeni B, Agarwal A, Case B. Imaging of neurosarcoidosis: common, uncommon, and rare. Clin Radiol. 2016 Jan;71(1):96–106.
4. Stern BJ, Royal W, Gelfand JM, et al. Definition and Consensus Diagnostic Criteria for Neurosarcoidosis: From the Neurosarcoidosis Consortium Consensus Group. JAMA Neurol. 2018 Dec 1;75(12):1546–53.
5. Zajicek JP, Scolding NJ, Foster O, et al. Central nervous system sarcoidosis--diagnosis and management. QJM. 1999 Feb;92(2):103–17.

Most read articles by the same author(s)