RESUMO
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.
RESUMO
Although anti-myelin-associated glycoprotein (MAG) antibody neuropathy is reported as a slowly progressive disease, it can lead to significant disability and impairment of health-related quality of life (HR-QoL) and social participation. The aim of this cross-sectional study was to evaluate the functioning and HR-QoL determinants in 67 patients with anti-MAG neuropathy in terms of the International Classification of Functioning, Disability, and Health (ICF). Evaluations included: Medical Research Council (MRC) sum score, Sensory Modality Sum score (SMS), Berg balance scale (BBS), Fatigue Severity Scale (FSS), Visual Analogue Scale (VAS) for pain, 9-Hole Peg Test (9-HPT), 6-min Walk Distance (6MWD), Impact on Participation and Autonomy (IPA) and the physical component score (PCS) and mental component score (MCS) of the short-form-36 health status scale (SF-36) HR-QoL measure. In the regression models, 6MWD was the most reliable predictor of PCS, explaining the 52% of its variance, while the strongest determinants of 6MWD were BBS and FSS, explaining the 41% of its variance. Consistently, VAS and BBS were good predictor of PCS, explaining together 54% of its variance. FSS was the most reliable determinant of MCS, explaining 25% of its variance. SMS and MRC were not QoL determinants. The results of our study suggest that 6MWD and FSS might be considered as potential meaningful outcome measures in future clinical trials. Furthermore, neurorehabilitation interventions aimed at improving balance and walking performance, fatigue management, and specific pain relief therapy should be considered to ameliorate participation in social life and HR-QoL in anti-MAG neuropathy patients.