Raised serum S100B protein levels in neuropsychiatric lupus

OBJECTIVE

To test serum S100B protein levels in patients with and without neuropsychiatric systemic lupus erythematosus (NPSLE) and controls.

METHODS

87 patients with SLE, 23 with and 64 without neuropsychiatric involvement, and 25 control subjects were prospectively evaluated. NPSLE diagnosis was made according to the American College of Rheumatology nomenclature and case definitions for neuropsychiatric lupus syndromes. Serum S100B protein levels were determined with a luminescence immunoassay. Statistical analysis was performed using Mann-Whitney and Kruskal-Wallis tests.

RESULTS

Among the patients with NPSLE, 9 presented psychosis; 4, cranial neuropathy; 3, cerebrovascular disease; 1, seizures; 1, chorea; 1, peripheral polyneuropathy; 1, multiplex mononeuropathy; 3, dementia. Serum concentrations of S100B protein were significantly higher in patients with NPSLE (median 0.164 ng/ml, interquartile range 0.113-0.332) than in non-NPSLE patients (0.062 ng/ml, 0.026-0.109) and controls (0.088 ng/ml, 0.013-0.124) (p<0.001). Patients with anti-dsDNA antibodies had higher S100B protein levels (p = 0.001). No significant associations were found of lupus activity (among non-NPSLE cases), antiphospholipid antibodies, and reduced complement levels with S100B concentration.

CONCLUSIONS

Serum S100B protein level is raised in NPSLE, reflecting continuing neurological damage. The association of anti-dsDNA antibodies with higher S100B protein concentration deserves further study.

The ischemic rat heart releases S100B

S100B is an astrocytic protein assessed in cerebrospinal fluid and serum as a biochemical marker of cerebral injuries. However, increasing evidences suggest the influence of extra cerebral sources on its serum levels. Since it was reported that the injured myocardium expresses S100B, we investigated whether the isolated heart releases this protein. The rat hearts were excised and perfused by the Langendorff technique of isolated heart perfusion. After stabilization, 10 hearts (ischemic group) were submitted to 20 minutes of ischemia and 30 minutes of reperfusion, and 5 hearts (control group) were submitted to 50 minutes of perfusion. The perfusion fluid was collected at pre-ischemia, and 0, 5, 10, 15 and 30 min after ischemia (or equivalent in controls) for S100B and cardiac troponin T (a heart injury marker) assays. In the ischemic group, S100B and troponin T levels increased significantly at time 0 min: S100B values [mug/L, median (IQ25/IQ75)] increased from < or = 0.02 (< or = 0.02/0.03) to 0.38 (0.22/0.84), while troponin T values [mug/L, median (IQ25/IQ75)] increased from 0.31 (0.15/0.45) to 2.84 (2.00/3.63). Our results point to the ischemic heart as an extra cerebral source of S100B.

S100B and NSE serum concentrations in Machado Joseph disease

BACKGROUND

NSE and S100B are considered as neuronal and glial peripheral markers of central nervous system pathologies, respectively. We evaluated the potential use of S100B and NSE serum concentrations as peripheral markers of symptomatic patients with Machado Joseph disease (MJD).

METHODS

We measured S100B and NSE peripheral concentrations of 22 MJD patients and compared with healthy subjects concentrations. The correlations of both markers with CAG repeat size, age of onset, disease duration, and the scores of the Extended Disability Status Scale of Kurtzke, Unified Parkinson's Disease Rating Scale, and the Montgomery-Asberg depression rating scale were also assessed.

RESULTS

S100B serum concentrations between control and MJD subjects were not statistically different, whereas NSE serum concentrations were higher in MJD patients than in control subjects (p=0.00001). S100B presented a moderate correlation with disease duration and depression score, whereas NSE presented a moderate correlation with depression score and a good negative correlation with EDSS score.

CONCLUSIONS

Symptomatic MJD patients present increased concentrations of NSE and normal concentrations of S100B in blood.

S100B and NSE serum levels in patients with Parkinson's disease

We evaluated S100B protein and neuron-specific enolase (NSE) serum levels in Parkinson's disease (PD) patients and their correlation with the severity of disease. The levels of S100B (P=0.16) and NSE (P=0.39) between PD and controls were similar. However, S100B levels correlated positively with the Hoehn and Yahr scale (r=0.368; P=0.02) and negatively with the Activities of Daily Living (ADL) scale (r=-0.431; P=0.006). Therefore, S100B and NSE may not have a diagnostic role in PD, but S100B may have a potential role as a marker of disease progression. The study of S100B may also contribute to elucidate the controversial role of glial cells in PD.

Influence of anticoagulants on the measurement of S100B protein in blood

OBJECTIVE

Evaluate anticoagulants influence on blood S100B levels.

DESIGN AND METHODS

Blood from 18 healthy adult subjects were collected using: no anticoagulants; EDTA; heparin; and citrate. S100B levels were determined using LIA-mat assay.

RESULTS

Heparin and citrate increased S100B levels (p<0.001), whereas EDTA had no effect (p=0.24). Heparin samples were highly (r2=0.97, p<0.001), citrate samples were moderately (r2=0.49, p<0.001), and EDTA samples were not (r2=0.22, p=0.059) correlated with serum samples.

CONCLUSION

When anticoagulant is required, heparin should be the primary choice.

Interictal serum S100B levels in chronic neurocysticercosis and idiopathic epilepsy

OBJECTIVE

To assess whether serum S100B levels could reflect a glial response in patients with epilepsy secondary to neurocysticercosis (NCC) and with idiopathic epilepsy.

SUBJECTS AND METHODS

Serum S100B levels were measured using an immunoluminometric assay in 20 patients with focal epilepsy related to chronic NCC (NCC group), and 19 patients with focal epilepsy (EPI group), matched by epidemiological and clinical data. Epileptic patients were compared with 20 healthy controls (CON group) matched by age and sex.

RESULTS

No difference was observed in S100B levels among NCC, EPI and CON groups (P>0.39). Serum S100B levels were not affected by antiepileptic drugs, frequency and type of seizures. Preliminarily, significantly higher levels of S100B were observed in patients with bilateral electroencephalographic (EEG) findings than in patients with unilateral and normal EEG findings (P<0.05).

CONCLUSION

Serum S100B is normal in patients with focal epilepsy related or not to chronic NCC.

Influence of anticoagulants on the measurement of S100B protein in blood

OBJECTIVE

Evaluate anticoagulants influence on plasma S100B levels.

DESIGN AND METHODS

Blood were collected from 18 healthy adult subjects using: no anticoagulants, EDTA, heparin, and citrate. S100B levels were determined using LIA-mat assay.

RESULTS

Heparin plasma and citrate increased plasma S100B levels (p < 0.001), whereas EDTA had no effect (p = 0.24). Heparin plasma samples were highly (r2 = 0.97, p < 0.001), citrate samples were moderately (r2 = 0.49, p < 0.001), and EDTA samples were not (r2 = 0.22, p = 0.059) correlated with serum samples.

CONCLUSIONS

When anticoagulant is required, heparin plasma should be the primary choice for measurement of S100 B levels.

Elevated serum S100B protein in drug-free bipolar patients during first manic episode: a pilot study

S100B protein is a calcium-binding protein mostly derived from glial cells, which exerts trophic or toxic effects on neural cells depending on its concentration. Since serum S100B levels has been tested as a potential marker in neuropsychiatric disorders, and structural abnormalities on glial cells have been recently associated with bipolar disorder patients, we conducted this preliminary study to examine if S100B serum levels are altered during first manic episode. We quantitated S100B in serum of 40 subjects (20 unmedicated patients during manic episode and 20 healthy matched controls). The mean+/-S.D. values for S100B for bipolar subjects were 0.065+/-0.068 microg/l and 0.018+/-0.029 microg/l for healthy controls. Increased levels of S100B in bipolar mania was statistically significant (Wilcoxon signed ranks test, Z=-2.45, P=0.01). These preliminary findings suggest that mania may increase the levels of S100B in serum of bipolar disorder patients, which could be related to adaptative neural mechanisms in bipolar mania.

Serum S100B levels in patients with lupus erythematosus: preliminary observation

S100B is an astrocytic calcium-binding protein which has been proposed as a biochemical marker of brain damage or dysfunction in acute and chronic diseases. We investigated whether serum S100B levels could be related to systemic lupus erythematosus (SLE) activity. Patients were grouped as having inactive SLE (ISLE), active SLE without central nervous system (CNS) involvement (ASLE), or active SLE with unequivocal neurologic or psychiatric manifestation (NPSLE). The control group consisted of age- and sex-matched healthy blood donors. S100B levels were determined using a luminescence immunoassay. All SLE groups had higher levels of serum S100B than the control group. Among the SLE groups, significantly higher levels of serum S100B protein were found in the NPSLE group than in the ISLE and ASLE groups, and there was no significant difference in S100B levels between the ISLE and ASLE groups. These preliminary results point to a putative relevance of serum S100B protein levels in SLE patients, specifically concerning CNS involvement present in this disease.