Cerebrospinal fluid and serum prolactin in systemic lupus erythematosus with and without central nervous system involvement

Aim: Recent research has shown that prolactin (PRL) may participate in the pathogenesis of systemic lupus erythematosus (SLE) and hyperprolactinemia may be related to disease activity. The current study investigated both serum and cerebrospinal fluid (CSF) PRL in SLE patients and their possible relationship to central nervous system (CNS) involvement. Methods: Prolactin levels were determined by immunoradiometric assay. Serum PRL levels were detected in 80 patients with SLE and 25 matched healthy controls. Disease activity was scored by the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI). CSF PRL levels were detected in seven cases of CNS involving SLE, eight cases of non‐CNS involved inactive SLE and eight cases of non‐SLE CNS disorders. Results: Hyperprolactinemia was present in 40% of SLE patients. Serum PRL levels were significantly correlated with SLEDAI scores. There was no significant difference in serum PRL levels between SLE patients with or without CNS involvement, but the mean CSF PRL levels were higher in CNS‐involved SLE patients than in non‐CNS‐involved SLE and non‐SLE patients. There was no significant correlation between serum and CSF PRL levels. Conclusions: Our results suggest that high serum PRL levels correlate with active disease in SLE, but not with CNS involvement. CSF PRL levels in SLE patients correlate with CNS involvement, which indicates that CSF PRL may be involved in the pathogenesis of CNS‐SLE.     

Prolactin and interleukin-6 in neuropsychiatric lupus erythematosus

We investigated the levels of prolactin (PRL) and interleukin-6 (IL-6) in the cerebrospinal fluid (CSF) and serum of systemic lupus erythematosus patients with central nervous system involvement (CNS-SLE), and examined whether PRL and IL-6 have a relationship. Serum and CSF PRL and IL-6 were measured in the following groups of patients and controls: group I: seven patients with CNS-SLE; group II: three SLE patients without CNS involvement (non CNS-SLE); group III: 10 patients with neurocysticercosis; and group IV: six healthy women. The patients were clinically assessed. CSF PRL and IL-6 were elevated in group I (CNS-SLE) in comparison with all other groups (p<0.001). In addition, four of seven patients had higher levels of IL-6 and PRL in CSF than in serum. A positive correlation between PRL and IL-6 in CSF of SLE was observed (r=0.88,p<0.001). The mean serum PRL concentrations were not significantly different in all groups, but high levels of IL-6 were found in the serum of group I in comparison with groups II and IV (p<0.001). The serum levels of group III were not different from those of group I. These results demonstrate the presence of intrathecal synthesis and elevations of CSF PRL and IL-6 in active CNS-SLE involvement and indicate that measurements of CSF PRL and IL-6 may be useful in the evaluation of neuropsychiatric lupus erythematosus.     

Elevated levels of soluble fractalkine in active systemic lupus erythematosus: potential involvement in neuropsychiatric manifestations

OBJECTIVE: To determine levels of the soluble form of the chemokine fractalkine (sFkn) and its receptor, CX(3)CR1, in patients with systemic lupus erythematosus (SLE) with neuropsychiatric involvement (NPSLE) and in SLE patients without neuropsychiatric involvement, and to assess their relationship with disease activity and organ damage. METHODS: Levels of sFkn in serum and cerebrospinal fluid (CSF) were measured by enzyme-linked immunosorbent assay. Expression of Fkn and CX(3)CR1 was quantified using real-time polymerase chain reaction. Surface expression of CX(3)CR1 on peripheral blood mononuclear cells (PBMCs) was determined by flow cytometry. Disease activity and organ damage were assessed using the SLE Disease Activity Index (SLEDAI) and the Systemic Lupus International Collaborating Clinics/American College of Rheumatology (SLICC/ACR) Damage Index, respectively. RESULTS: Serum sFkn levels were significantly higher in patients with SLE than in patients with rheumatoid arthritis (RA) or healthy controls. In addition, significant correlations between serum sFkn levels and the SLEDAI, the SLICC/ACR Damage Index, anti-double-stranded DNA and anti-Sm antibody titers, immune complex levels (C1q), and serum complement levels (CH50) were observed. Expression of CX(3)CR1 was significantly greater in PBMCs from patients with active SLE than in those from RA patients or healthy controls. Levels of sFkn were also significantly higher in CSF from untreated patients with newly diagnosed NPSLE than in SLE patients without neuropsychiatric involvement; treatment reduced both serum and CSF levels of sFkn in patients with SLE. CONCLUSION: Soluble Fkn and CX(3)CR1 may play key roles in the pathogenesis of SLE, including the neuropsychiatric involvement. Soluble Fkn is also a serologic marker of disease activity and organ damage in patients with SLE, and its measurement in CSF may be useful for the diagnosis of NPSLE and followup of patients with NPSLE.     

Correlation of prolactin serum concentrations with clinical activity and remission in patients with systemic lupus erythematosus. Effect of conventional treatment

OBJECTIVE: The role of prolactin (PRL) in the pathogenesis of systemic lupus erythematosus (SLE) is controversial. The effect of conventional treatment (steroids, antimalarials, immunosuppressor drugs) on PRL concentrations is unclear. We investigated correlation of PRL levels with lupus activity in patients at entry and after 6 months of conventional treatment. METHODS: We studied 43 female patients with active SLE, who were divided in 2 groups; Group 1: 16 patients with minor organ involvement (cutaneous and articular involvement), and Group 2: 27 patients with major organ involvement (glomerulonephritis). Controls were 36 healthy individuals. PRL levels were determined by an immunoradiometric assay at entry and after 6 months of treatment. PRL levels were correlated with SLE Disease Activity Index (SLEDAI) score. RESULTS: Mild hyperprolactinemia (HPRL, 20-40 ng/ml) was found in 30/43 (69.7%) SLE patients. After 6 months of treatment a reduction in PRL levels was found in both groups: Group 1: 24.3 +/- 10.8 to 16.96 +/- 10.87 ng/ml (p < 0.001); and Group 2: 23.6 +/- 5.7 to 12.07 +/- 11.13 ng/ml (p < 0.001). The SLEDAI score also decreased after treatment: Group 1: 16.5 +/- 5.9 to 2.1 +/- 1.3 (p < 0.001); Group 2: 16.8 +/- 5.4 to 1.6 +/- 1.4 (p < 0.001). At entry and after treatment, a significant correlation between PRL levels and SLEDAI score was found in all patients (r = 0.4946, p = 0.0007, and r = 0.9086, p = 0.0001, respectively). CONCLUSION: HPRL was associated with SLE disease activity. Conventional immunosuppressive therapy decreased PRL levels in direct correlation with decreased SLE activity. This finding emphasizes that PRL may play a role in the pathogenesis and clinical expression of SLE.     

Elevated serum bioactive prolactin concentrations in patients with systemic lupus erythematosus are associated with disease activity as disclosed by homologous receptor bioassays

OBJECTIVE: To assess the bioactivity of circulating prolactin (PRL) in serum samples from patients with systemic lupus erythematosus (SLE) using 2 novel homologous in vitro bioassays, and to correlate PRL bioactivity with lupus activity. METHODS: Serum samples from 98 SLE patients with and without disease activity were tested for immunoreactive and bioactive concentrations of PRL. RESULTS: Patients with active disease exhibited higher bioactive serum PRL levels in homologous bioassays (p 相似文献   

Profile of sex hormones in male patients with systemic lupus erythematosus

OBJECTIVE: To study the profile of sex hormones in male patients with systemic lupus erythematosus (SLE). METHOD: Serum prolactin (PRL), testosterone (T), estradiol (E2), follicle-stimulating hormone (FSII) and luteinizing hormone (LH) levels were obtained from 35 males with SLE and compared with 33 age-matched normal controls. RESULTS: No significant differences in serum T, E2, PRL levels and E2/T ratio were observed between male SLE patients and controls. However, patients with SLE had significantly higher levels of gonadotrophins (FSH, LH). Five (14%) SLE patients, but none of the controls, had both low testosterone and elevated LH. Hypoandrogenic male SLE patients did not have overt features of hypogonadism but had a higher prevalence of central nervous system disease and scrositis than those with normal androgen levels. Discase flares, on the other hand, were not significantly more frequent in these patients. Although PRL or T levels per se did not correlate with disease activity in our patients, the ratio of PRL to T showed a significant correlation with SLEDAI scores (p = 0.42. P = 0.01). CONCLUSIONS: Hypoandrogenism is present in some male patients with SLE and may be relevant in disease pathogenesis. However, whether these hormonal abnormalities are intrinsic to SLE or the consequence of any non-specific chronic disorders cannot be distinguished from the current data. Further studies involving a larger number of subjects and inclusion of other disease controls are needed.     

系统性红斑狼疮患者外周血基质金属蛋白酶-3检测及其临床意义

目的　检测系统性红斑狼疮 (SLE)患者外周血清基质金属蛋白酶 3 (MMP 3)水平并探讨其临床意义。方法　MMP 3检测采用ELISA方法。结果　SLE患者血清MMP 3水平为99 86ng/ml(中位数 ,下同 )显著高于正常对照组 2 7 82ng/ml (P <0 0 0 1)。SLE患者中 ,发生神经精神性狼疮者MMP 3水平显著高于非神经精神性狼疮患者 (P <0 0 1) ,发生狼疮肾炎者MMP 3亦明显高于无肾损害者 (P <0 0 5 ) ,而发生多发性关节炎和颊部皮疹 /光敏感患者分别与无多发性关节炎和颊部皮疹 /光敏感患者的MMP 3水平差异无显著性 (P >0 0 5 ) ;出现抗dsDNA抗体阳性、低补体C3血症、低白蛋白血症、高IgG血症及血肌酐升高者血清MMP 3水平均分别显著高于无上述表现者 (P <0 0 5 ) ,SLE患者血清MMP 3水平与SLEDAI呈正相关关系 (P <0 0 5 )。结论　SLE患者血清中MMP 3水平显著升高 ,可作为狼疮活动的参考指标之一。MMP 3参与SLE的病理生理过程 ,与SLE的某些临床检验异常表现及狼疮脑、肾等脏器损害有关     

Elevated bioactive prolactin levels in systemic lupus erythematosus--association with disease activity.

OBJECTIVE. To assess the possibility that prolactin (PRL) is involved in the pathogenesis of systemic lupus erythematosus (SLE). METHODS. We determined serum PRL levels in 122 serum samples from 78 unselected patients with SLE (73 women, 5 men, age range 16-71 yrs). Disease activity was defined according to Lupus Activity Criteria Count (LACC) and scored by Systemic Lupus Disease Activity Index (SLEDAI). Serum PRL concentrations were determined by immunoradiometric assay (IRMA) and by biological assay (BA) that evaluates Nb2 lymphoma cell proliferation. RESULTS. Hyperprolactinemia (> 20 ng/ml) was found in 21 patients (26.9%) by IRMA and in 31 (39.7%) by BA. A significant correlation between IRMA and BA PRL levels was found (rs 0.46, p < 0.001). According to LACC, SLE was active in 29 patients and inactive in 49. In those with active disease median PRL levels were higher both by IRMA (18.5 ng/ml, range 2.2-51.2 vs 10.6 ng/ml, range 3.9-29.6; p < 0.001) and BA (21.0 ng/ml, range 12.4-84 vs 14.9 ng/ml, range 4.2-46.1; p < 0.001). Hyperprolactinemia was associated with active disease in 13/21 patients (61.9%) by IRMA and in 18/31 (58.1%) by BA (p < 0.01). SLEDAI scores correlated with PRL levels both by IRMA (rs 0.5, p < 0.001) and BA (rs 0.41, p < 0.02). A followup analysis on serum samples from 44 patients seen again after 6-8 mo confirmed the above results. There was no difference in the rate of different clinical manifestations in hyperprolactinemic and normoprolactinemic subjects, apart from the increased prevalence of malar rash and central nervous system manifestations in the patients with hyperprolactinemia (p < 0.03 and p < 0.01, respectively). CONCLUSION: Hyperprolactinemia was frequently detected in patients with SLE by IRMA and by BA and was associated with disease activity. Our findings suggest that PRL may play a role in the pathogenesis of SLE.     

The relationship between serum ferritin levels and disease activity in systemic lupus erythematosus

OBJECTIVE: The aim of this study is to investigate the relationship between serum ferritin levels and disease activity in patients with systemic lupus erythematosus (SLE). METHODS: Serum ferritin levels of 72 SLE patients were measured. The SLE patients were subdivided into two groups according to SLE disease activity index (SLEDAI) as < or = 10 and > or = 11. The results were compared with 31 patients with rheumatoid arthritis (RA). 36 patients among 72 with SLE were evaluated before and after treatment. RESULTS: Serum levels of ferritin in SLE patients were higher than RA patients (p < 0.001). There was a significant difference in ferritin levels before and after treatment. The levels of ferritin in SLE were positively correlated with SLEDAI scores. Patients with SLEDAI scores > or = 11 had significantly higher serum ferritin levels. CONCLUSION: Serum ferritin levels may be a useful marker of disease activity in SLE patients.     

Cell-ELISA detection of antineuronal antibodies in central nervous system involvement in systemic lupus erythematosus

OBJECTIVE: To develop a cell-ELISA method to detect antineuronal antibodies (anti-Ns) and evaluate the diagnostic value of anti-Ns in central nervous system involvement in systemic lupus erythematosus (CNS-SLE). METHOD: Anti-N was assessed in both serum and cerebrospinal fluid (CSF) samples from 38 patients with CNS-SLE, 29 with SLE without CNS involvement (non-CNS-SLE), 36 with other rheumatic diseases and 59 with non-rheumatic diseases with the CNS manifestations using a cell-ELISA method with 1% paraformaldehyde-fixed SK-N-MC neuroblastoma cells as substrate. Serum samples from 37 healthy donors were also included in this study. Patients with CNS-SLE who were anti-N positive in CSF were studied serially for CSF anti-N levels at times of treatment-associated improvement in CNS symptoms. RESULTS: Serum anti-N levels were significantly increased in patients with SLE compared with other groups, with a sensitivity of 61.2% (41/67) and a specificity of 91.8% (p<0.001). CSF anti-N levels were significantly increased in patients with CNS-SLE, with a sensitivity of 47.4% (18/38) and a specificity of 89.7%, whereas only 10.3% (3/29) of patients with non-CNS-SLE had increased anti-N in CSF (p<0.001). CSF anti-N levels decreased significantly after effective treatment of CNS-SLE (p<0.05). CONCLUSION: Serum anti-N is relatively specific to SLE. CSF anti-N is a sensitive and relatively specific antibody in diagnosing CNS-SLE and correlates with CNS-SLE activity.     

Prolactin in human systemic lupus erythematosus.

In the last decade, evidence has accumulated to support the hypothesis that both mild and moderate elevations of serum prolactin (PRL) participate in the clinical expression and pathogenesis of systemic lupus erythematosus (SLE). Hyperprolactinemia (HPRL) has been found in 20-30% of patients with SLE. HPRL seems to be associated with clinical activity of SLE during pregnancy. Although the relationship between HPRL and active SLE in non-pregnant patients is controversial, recent clinical and experimental studies support the potential role of prolactin (PRL) as a promoter of clinical activity and severity of SLE. Mild elevations of serum PRL secondary to microadenoma could trigger the onset of SLE in a subset of patients. Elevated PRL and interleukin (IL)-6 have been found in the urine of patients with active lupus nephritis and in cerebrospinal fluid (CSF) of patients with active central nervous system (CNS) SLE. PRL may therefore participate in the pathogenesis of lupus nephritis and cerebritis, and the presence of PRL may reflect an abnormal communication between the immune system and the neuroendocrine system in active SLE. Lymphocytes from patients with active SLE produce increased amounts of PRL, and this extrapituitary PRL may participate in aberrant immune processes in SLE. There is exciting new evidence that HPRL in SLE may be explained by stimulation of pituitary PRL secretion by cytokines. In addition, defects in peptidergic modulators and dopamine metabolism have been described in patients with SLE. The interactions between PRL, cytoquines, autoantibodies and organ involvement suggest that PRL participates in local and generalized immune and inflammatory processes and acts as a bridge between the neuroendocrine and immune systems in SLE. Understanding the interactions between these systems in SLE will help us to understand and treat this important autoimmune disease.     

Serum free light chains as biomarkers for systemic lupus erythematosus disease activity

Objective

To evaluate serum free light chains (FLC) as a putative biomarker of systemic lupus erythematosus (SLE) activity.

Methods

Seventy‐five SLE patients and 41 age‐ and sex‐matched rheumatoid arthritis (RA) controls were enrolled. Disease activity was assessed using the Safety of Estrogens in Lupus Erythematosus: National Assessment version of the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) definition and physician global assessments for SLE and the Disease Activity Score in 28 joints for RA. Serum FLC levels were compared against other biomarkers (IgG, C3, C4, double‐stranded DNA [dsDNA] antibody). Nonparametric tests were used to compare 1) FLC and IgG in SLE versus RA and healthy controls, 2) FLC and IgG among different levels of activity in SLE, and 3) FLC in active versus nonactive RA. Correlation of FLC, C3, C4, dsDNA antibody, and IgG with the SLEDAI and modified SLEDAI (M‐SLEDAI) were obtained.

Results

FLC was higher in SLE than in RA; both were higher than referent healthy controls. Total FLC was significantly higher in subjects with greater SLE disease activity than lower/no activity. There were no significant differences in IgG, C4, or dsDNA antibody stratified by disease activity. Total FLC and C3 showed moderate to strong correlation with the SLEDAI and M‐SLEDAI. In RA, no differences were seen in FLC levels for different levels of disease activity. Similar results were seen after controlling for renal function, age, and sex. In multiple linear regression, FLC significantly explained 50% variance of the SLEDAI after adjusting for renal function, age, and sex.

Conclusion

Serum FLC levels correlate strongly with disease activity in SLE, but not in RA. Serum FLC may be used as a biomarker of SLE disease activity.     

Elevated levels of interleukin-6 in cerebrospinal fluid from patients with systemic lupus erythematosus and central nervous system invol vement

Paired serum and cerebrospinal fluid (CSF) specimens from 14 patients with systemic lupus erythematosus (SLE) and central nervous system (CNS) involvement were studied for interleukin-6 (IL-6) activity using the IL-6-dependent murine hybridoma, MH60.BSF2. We also studied 23 patients with noninflammatory neurologic diseases, and 9 SLE patients without CNS involvement. CSF IL-6 activity was elevated only in SLE patients with CNS involvement, although there was no significant difference in serum IL-6 activity among the 3 groups. CSF IL-6 activity was not correlated with either the CSF-serum albumin quotient (Q albumin; an indicator of blood-brain barrier function) or serum IL-6 activity in SLE patients with CNS involvement. The CSF IL-6 activity decreased significantly when CNS manifestations subsided after successful treatment. These results indicate that determination of CSF IL-6 activity may be useful in the evaluation of CNS disease activity in SLE. Moreover, the data confirm the presence of immune system activation within the CNS in patients with SLE-associated CNS disease.     

Elevated levels of interleukin-6 in cerebrospinal fluid from patients with systemic lupus erythematosus and central nervous system involvement

Paired serum and cerebrospinal fluid (CSF) specimens from 14 patients with systemic lupus erythematosus (SLE) and central nervous system (CNS) involvement were studied for interleukin-6 (IL-6) activity using the IL-6-dependent murine hybridoma, MH60.BSF2. We also studied 23 patients with noninflammatory neurologic diseases, and 9 SLE patients without CNS involvement. CSF IL-6 activity was elevated only in SLE patients with CNS involvement, although there was no significant difference in serum IL-6 activity among the 3 groups. CSF IL-6 activity was not correlated with either the CSF-serum albumin quotient (Q albumin; an indicator of blood-brain barrier function) or serum IL-6 activity in SLE patients with CNS involvement. The CSF IL-6 activity decreased significantly when CNS manifestations subsided after successful treatment. These results indicate that determination of CSF IL-6 activity may be useful in the evaluation of CNS disease activity in SLE. Moreover, the data confirm the presence of immune system activation within the CNS in patients with SLE-associated CNS disease.     

Flow cytometric assessment of anti-neuronal antibodies in central nervous system involvement of systemic lupus erythematosus and other autoimmune diseases

The objective of this study is to evaluate the association between anti-neuronal antibody (anti-NA) and central nervous system (CNS) manifestations of systemic lupus erythematosus (SLE) and other rheumatic diseases using a flow cytometric method. Anti-NA was measured by flow cytometry in serum and cerebrospinal fluid (CSF) samples from patients with SLE (n=44 for serum, n=17 for CSF), other rheumatic diseases (n=64 for serum, n=21 for CSF) and from healthy controls (n=65 for serum, n=18 for CSF). Serum anti-NA was more frequently observed in SLE (31.8%, 14/44) than in other rheumatic diseases (4.7%, 3/64, P<0.001) or in healthy controls (0%, 0/65, P<0.00001). In SLE patients, the frequency of serum anti-NA was significantly higher in CNS-SLE (76.5%, 13/17) than in non CNS-SLE (3.7%, 1/27, P<0.000001). CSF anti-NA was detected in 88.2% (15/17) of CNS-SLE and was more frequently detected in CNS-SLE (15/17, 88.2%) than in other rheumatic diseases with CNS involvement (1/21, 4.8%, P<0.000001) or in healthy controls (0/18, P<0.000001). In conclusion, serum anti-NA was more frequently found in CNS-SLE than in non CNS-SLE, other rheumatic diseases or in healthy controls. The frequency of CSF anti-NA in CNS-SLE was significantly higher than in other rheumatic diseases with CNS involvement or in healthy controls.     

Association of psychiatric manifestations with antibodies to ribosomal P proteins in systemic lupus erythematosus

PURPOSE: The goal of this study was to determine whether elevated serum levels of antibodies to ribosomal P proteins (anti-P antibodies) are associated with neuropsychiatric manifestations in patients with systemic lupus erythematosus (SLE). Additional experiments examined characteristics of these antibodies that might be associated with pathogenicity. PATIENTS AND METHODS: A large number of serum samples were collected from patients with SLE, control subjects with other rheumatic diseases, and normal individuals. At the time serum samples were obtained, patients with SLE were categorized according to the presence of psychosis, depression, and other manifestations of central nervous system (CNS) involvement. Serum anti-P antibody activity was quantitated by an enzyme-linked immunosorbent assay utilizing a synthetic peptide corresponding to the major P protein epitope. RESULTS: In a group of 79 normal individuals, mean (+/- SE) IgG anti-P activity was 0.01 +/- 0.003 and no individuals had values greater than 3 SD above the mean. Similar results were obtained measuring IgM anti-P activity. Normal levels were found in all sera from 21 patients with rheumatoid arthritis. Of 119 patients demonstrating various patterns of antinuclear and anticytoplasmic antibody activity, elevated anti-P levels were found only in patients with SLE. Overall, 19% of 269 patients with SLE demonstrated elevated levels of IgG or IgM anti-P antibodies, including 14% of 187 patients without and 29% of 82 patients with neuropsychiatric manifestations. The frequency of positive test results varied greatly depending on the nature of the CNS involvement. The frequency in patients with severe depression (n = 8) and psychosis (n = 29) was 88% and 45%, respectively, compared with only 9% in patients with nonpsychiatric neurologic disease (n = 45). For the entire SLE group, the odds ratio for the association of anti-P antibodies and severe psychiatric manifestations was 7.63 with a 95% confidence interval of 3.61 to 16.14. In a review of 187 patients with SLE originally classified as not having severe psychiatric disease, seven of 10 patients being treated with antidepressant medications had elevated levels of anti-P antibodies. In serial studies, the serum level of anti-P antibodies appeared to correlate with the activity of psychiatric disease and did not correlate with the activity of other manifestations of SLE. Anti-P antibodies in nearly all patients were IgG and directed primarily to the C-terminal 11 amino acids of the P protein. No difference in these characteristics was observed when patients with and without psychiatric manifestations were compared. Paired serum and cerebrospinal fluid (CSF) samples were also obtained from eight patients with active neuropsychiatric disease. Even when expressed as a fraction of the total IgG present, anti-P activity was markedly lower in CSF than in serum. CONCLUSIONS: Elevated levels of autoantibodies to the C-terminal region of ribosomal P proteins appear to be a specific marker for SLE, and are associated with both severe depression and psychosis in this disease. This assay is easily reproducible and may help distinguish SLE-induced psychiatric disease from that caused by other processes.     

Correlation of serum prolactin levels and disease activity in systematic lupus erythematosus

To assess the frequency of hyperprolactinaemia and its possible clinical significance in patients with systemic lupus erythematosus (SLE). In this cross-sectional study, we determined serum prolactin (PRL) levels in 60 SLE female patients (age range 15–60 years). Disease activity was defined according to the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI). Serum PRL concentrations were determined by immunoradiometric assay. Elevated serum concentrations of PRL (>20 ng/ml) were found in 5 of 60 (8.4%) patients. No direct correlation between PRL levels with disease activity of SLE was found (r = 0.062, P = 0.39). SLE was active in 23 patients (SLEDAI ≥ 6) and inactive in 37 (SLEDAI < 6). In those with active disease, median PRL levels were lower (11.0 ng/ml) than normoprolactinaemic group (12.1 ng/ml). There was no significant difference in serum PRL levels between active and non-active patients (P = 0.07). There was a significant difference in the frequency of several clinical manifestations and serological parameters between SLE patients with normal and high prolactin (renal involvement, haematological manifestation and anti-ds DNA). This study has shown that hyperprolactinaemia is prevalent in random SLE patients. The elevated PRL levels seem not to be associated with disease activity. The mechanism and pathoaetiological and clinical significance of hyperprolactinaemia in a small subset of SLE patients remain unclear and a longer follow-up is necessary.     

Increased levels of serum protein oxidation and correlation with disease activity in systemic lupus erythematosus

OBJECTIVE: To examine protein oxidation in systemic lupus erythematosus (SLE) and to correlate levels of protein oxidation products with disease activity. METHODS: Serum was collected from SLE patients and healthy control subjects. Protein-bound carbonyls and the pro-oxidant enzyme myeloperoxidase (MPO) were quantified by enzyme-linked immunosorbent assay. Protein thiols were quantified using 5,5'-dithionitrobenzoic acid. Protein-bound amino acids and methionine, tyrosine, and phenylalanine oxidation products were quantified by acid hydrolysis and high-performance liquid chromatography. Disease activity was assessed by the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI). Levels of anti-double-stranded DNA (anti-dsDNA) antibodies were measured by radioimmunoassay. RESULTS: Compared with control subjects, SLE patients exhibited elevated levels of protein carbonyls (0.108 +/- 0.078 versus 0.064 +/- 0.028 nmoles/mg of protein; P = 0.046), decreased levels of protein thiols (3.9 +/- 1.1 versus 4.9 +/- 0.7 nmoles/mg of protein; P = 0.003), decreased levels of protein-bound methionine (P = 0.0007), and increased levels of protein-bound methionine sulfoxide (P = 0.0043) and 3-nitrotyrosine (P = 0.0477). SLE patients with high SLEDAI scores or elevated anti-dsDNA antibody levels exhibited increased oxidation compared with patients with low SLEDAI scores or low antibody levels. Serum MPO levels were decreased in SLE patients (P = 0.03), suggesting that this enzyme is not responsible for the enhanced protein oxidation. CONCLUSION: We found elevated levels of multiple markers of protein oxidation in sera from SLE patients compared with controls, and these levels correlated with disease activity. The findings suggest that protein oxidation may play a role in the pathogenesis of chronic organ damage in SLE.     

Intrathecal cytokines in systemic lupus erythematosus with central nervous system involvement

Symptoms originating from central nervous system (CNS) are frequently occuring in patients with systemic lupus erythematosus (SLE). Reliable diagnostic markers for this condition are presently lacking. Importantly, CNS involvement in lupus patients is associated with increased morbidity and mortality. The aim of this retrospective evaluate was to study the diagnostic value of cerebrospinal fluid (CSF) cytokine levels in SLE patients with CNS involvement. 34 patients with SLE were hospitalized and investigated for the presence of CNS lupus. These patients were evaluated clinically and with magnetic resonance imaging (MRI) and CSF analyses, as well as with neuropsychiatric tests. 13 patients were found to have CNS lupus whereas another four of the patients fulfilled the criteria for CNS involvement but were excluded from this group due to other causes of CNS involvement. Lastly, in 17 SLE cases, the diagnosis of CNS lupus could not be confirmed. CSF levels of interleukin-6 (IL-6) and IL-8, as well as the CSF/serum IL-6 ratio, were elevated in the CNS lupus group, compared with the 17 SLE patients not fullfilling a diagnosis of cerebral lupus. Interestingly, follow-up of five patients being successfully treated for CNS lupus revealed profound decrease of intrathecal IL-6 levels. These results indicate that analysis of CSF cytokine levels, especially IL-6 and IL-8, may be useful in the diagnostics and possibly follow-up of SLE patients with cerebral lupus.     

Increased CD28 serum levels are not associated with specific clinical activity in systemic lupus erythematosus

CD28 is one of the main activator receptors involved in systemic lupus erythematosus (SLE) pathogenesis, and its expression and serum levels are significantly higher in patients with SLE and other autoimmune diseases than in healthy controls (HC). However, it is unknown whether this increase is associated with specific organ damage. Therefore, our objective was to measure the CD28 levels in serum from SLE and HC groups to confirm the CD28 serum levels increase, as reported previously, and to determine whether this increase was associated with specific organ activity and the SLE Disease Activity Index (SLEDAI). Forty SLE patients and 40 matched HC were included, and the age, disease duration, SLEDAI and Mexican SLEDAI were recorded for the SLE group. CD28 serum levels were measured by ELISA. There was a statistically significant increase in the CD28 serum levels of SLE patients compared to controls (p = 0.039); however, we did not find any significant correlation with disease activity indices or organ involvement, although we found a significant but low correlation with C3. Our results and a review of the literature suggest that the increase in CD28 serum levels may be the result of CD28 gene overexpression, which could be related to the decrease in CD28+ T cells, T-cell hyporesponsiveness and immune impairment that occurs in SLE.