Dark Rims: Novel Sequence Enhances Diagnostic Specificity in Multiple Sclerosis

BACKGROUND AND PURPOSE

The 2010 McDonald criteria are designed to sensitively detect MS; however, the low specificity of these criteria can occasionally lead to the misdiagnosis of MS. The purpose of this study was to determine whether a novel double inversion recovery MR imaging technique has the potential to increase the specificity of diagnostic criteria distinguishing MS from non-MS white matter lesions.

MATERIALS AND METHODS

This was a cross-sectional observational study. MR imaging data were acquired between 2011 and 2016. A novel double inversion recovery sequence that suppresses CSF and GM signal was used (GM-double inversion recovery). We compared WM lesions in a group of patients with multiple sclerosis and in a second group of positive controls with white matter lesions who did not have a diagnosis of MS. The presence of a rim on the GM-double inversion recovery MR imaging sequence was combined with the 2001 and 2010 McDonald disseminated-in-space criteria. Multiple MR imaging markers, including lesion location, size, and the presence of a rim, were compared between groups as well as a quantitative measure of lesion T1 hypointensity.

RESULTS

MR images from 107 patients with relapsing-remitting MS (median age, 32 years) and 36 positive control (median age, 39 years) subjects were analyzed. No significant differences were found in age and sex. In patients with MS, 1120/3211 lesions (35%) had a rim on GM-double inversion recovery; the positive control group had only 9/893 rim lesions (1%). Rims were associated with a decrease in the lesion T1 ratio. Using the 2010 MR imaging criteria plus the presence of rims on GM-double inversion recovery, we achieved 78% and 97% specificity in subjects with ≥1 and ≥2 rim lesions, respectively.

CONCLUSIONS

The addition of a novel GM-double inversion recovery technique enhanced specificity for diagnosing MS compared with established MR imaging criteria.

Modeling the relationship among gray matter atrophy, abnormalities in connecting white matter, and cognitive performance in early multiple sclerosis

BACKGROUND AND PURPOSE

Quantitative assessment of clinical and pathologic consequences of white matter abnormalities in multiple sclerosis is critical in understanding the pathways of disease. This study aimed to test whether gray matter atrophy was related to abnormalities in connecting white matter and to identify patterns of imaging biomarker abnormalities that were related to patient processing speed.

MATERIALS AND METHODS

Image data and Symbol Digit Modalities Test scores were collected from a cohort of patients with early multiple sclerosis. The Network Modification Tool was used to estimate connectivity irregularities by projecting white matter abnormalities onto connecting gray matter regions. Partial least-squares regression quantified the relationship between imaging biomarkers and processing speed as measured by the Symbol Digit Modalities Test.

RESULTS

Atrophy in deep gray matter structures of the thalami and putamen had moderate and significant correlations with abnormalities in connecting white matter (r = 0.39-0.41, P < .05 corrected). The 2 models of processing speed, 1 for each of the WM imaging biomarkers, had goodness-of-fit (R(2)) values of 0.42 and 0.30. A measure of the impact of white matter lesions on the connectivity of occipital and parietal areas had significant nonzero regression coefficients.

CONCLUSIONS

We concluded that deep gray matter regions may be susceptible to inflammation and/or demyelination in white matter, possibly having a higher sensitivity to remote degeneration, and that lesions affecting visual processing pathways were related to processing speed. The Network Modification Tool may be used to quantify the impact of early white matter abnormalities on both connecting gray matter structures and processing speed.

Delayed leptin administration after stroke induces neurogenesis and angiogenesis

Leptin is a potent AMP kinase (AMPK) inhibitor that induces neuroprotection, neurogenesis, and angiogenesis when administered immediately after stroke. To dissociate these effects, we explored the effects of delayed administration of leptin, at 10 days after stroke onset, on neurogenesis and angiogenesis after stroke. Sabra mice underwent photothrombotic stroke and were treated with vehicle or leptin given either as a single dose or in triple dosing, 10 days later. Newborn cells were labeled with bromodeoxyuridine. Functional outcome was studied with the neurological severity score for 90 days poststroke, and the brains were then evaluated via immunohistochemistry. Final infarct volumes did not differ between the groups. Exogenous leptin led to significant increments in the number of proliferating BrdU(+) cells in the subventricular zone and in the cortex abutting the lesion (2.5-fold and 1.4-fold, respectively). There were significant increments in the number of newborn neurons and glia (4- and 3.4-fold, respectively) in leptin-treated animals. Leptin also significantly increased the number of blood vessels in the perilesioned cortex. However, animals treated with leptin failed to demonstrate significantly better functional states. In conclusion, leptin induces neurogenesis and angiogenesis even when given late after stroke but does not lead to better functional outcome in this delayed-treatment paradigm. These results suggest that the main beneficial effects of leptin after stroke are associated with its early neuroprotective role rather than with its proneurogenic or proangiogenic effects.

Leptin induces neuroprotection neurogenesis and angiogenesis after stroke

Leptin is a potent AMP kinase (AMPK) inhibitor that is central to cell survival. Hence, we explored the effects of leptin on neurogenesis and angiogenesis after stroke. Neural stem cells (NSC) were grown as neurospheres in culture and treated with vehicle or leptin and neurosphere size and terminal differentiation were then determined. We then explored the effects of leptin on endogenous repair mechanisms in vivo. Sabra mice underwent photothrombotic stroke, were given vehicle or leptin and newborn cells were labeled with Bromo-deoxy-Uridine. Functional outcome was studied with the neurological severity score for 90 days post stroke and the brains were then evaluated with immunohistochemistry. In a subset of animals the brains were also evaluated for changes in the expression of leptin receptor and AMPK. In vitro, leptin led to a 2-fold increase in neurosphere size but did not change the differentiation of newborn cells. Following stroke, exogenous leptin led to a 4-fold increase in the number of NSC in the cortex abutting the lesion. There was a 1.5-fold increase in the number of newborn neurons and glia in leptin treated animals. Leptin also significantly increased the number of blood vessels in the peri-lesioned cortex. Leptin treated mice had increased expression of leptin receptor and increased phosphorylated AMPK concentration. Animals treated with leptin also had significantly better functional states. In conclusion, leptin induces neurogenesis and angiogenesis after stroke and leads to increased leptin receptor and pAMPK concentrations. This may explain at least in part the better functional outcome observed in leptin treated animals after stroke.

Autoantibodies to a NR2A peptide of the glutamate/NMDA receptor in sera of patients with systemic lupus erythematosus

OBJECTIVE

To determine the prevalence of autoantibodies directed against an epitope of the glutamate/N-methyl-D-aspartic acid (NMDA) receptor subunit NR2A (which is highly expressed in human brain) in the sera of lupus patients, and to investigate the possible correlation of these antibodies with clinical and serological manifestations of systemic lupus erythematosus (SLE).

METHODS

Sera were obtained from 109 consecutive SLE patients. Controls were 65 patients with myasthenia gravis, 19 with autoimmune polyendocrine syndrome type I (APS I), and 65 healthy donors. A 15 amino acid long peptide based on a sequence within the NR2A subunit of the NMDA/glutamate receptor was synthesised. Antibodies to this peptide were determined by enzyme linked immunosorbent assay. Antibodies against double stranded DNA (dsDNA) were measured by Chrithidia luciliae assay. Disease activity was determined using the SLE disease activity index (SLEDAI).

RESULTS

Sera of 34/109 SLE patients (31%) reacted specifically with the NR2A peptide compared with only 4/65 myasthenia gravis patients (6.1%, p<0.001), 1/19 APS I patients (5.3%, p<0.02), and 3/65 healthy controls (4.6%, p<0.001). No correlation was found between the presence of NR2A and dsDNA or anti-cardiolipin specific autoantibodies. In addition, no significant correlation was observed between the presence of NR2A specific antibodies and the SLEDAI score or any lupus related clinical manifestations.

CONCLUSIONS

A significant number of SLE patients (31%) have NR2A specific antibodies that do not correlate with anti-dsDNA antibodies. Additional studies of lupus patients with neurological disorders should elucidate the role of NR2A specific antibodies in lupus related CNS manifestations.

Use of colour duplex ultrasound to diagnose giant cell arteritis in a case of visual loss of uncertain aetiology

Giant cell arteritis is a common condition that can result in permanent visual loss. It has traditionally been diagnosed by invasive temporal artery biopsy in cases of clinical suspicion. The findings of colour duplex ultrasound have recently been described. We report the use of duplex ultrasound to diagnose temporal arteritis, with clinicopathological correlation, and discuss the possible application of this non-invasive technique to the management of giant cell arteritis.

Modulation of autoreactive responses of peripheral blood lymphocytes of patients with systemic lupus erythematosus by peptides based on human and murine anti-DNA autoantibodies

Two peptides, based on the sequences of the complementarity-determining regions (CDR) 1 and 3 of a pathogenic murine monoclonal anti-DNA autoatibody that bears the 16/6 idiotype (Id), were shown to either prevent or treat an already established systemic lupus erythematosus (SLE) in two murine models of lupus. Two additional peptides based on the human monoclonal anti-DNA, 16/6 Id were synthesized. This study was undertaken in order to investigate the ability of the CDR-based peptides to immunomodulate SLE-associated responses of peripheral blood lymphocytes (PBL) of SLE patients. PBL of 24 of the 62 SLE patients tested proliferated in vitro following stimulation with the human 16/6 Id. Peptides based on the CDRs of both the human and murine anti-DNA autoantibodies inhibited efficiently and specifically the 16/6 Id-induced proliferation and IL-2 production. The latter inhibitions correlated with an up-regulated production (by 2.5-3.5-fold) of the immunosuppressive cytokine, TGF-beta. Overall, the results of our study demonstrate that the CDR-based peptides are capable of down-regulating in vitro autoreactive T cell responses of PBL of SLE patients. Thus, these peptides are potential candidates for a novel specific treatment of SLE patients.

Ginseng improves pulmonary functions and exercise capacity in patients with COPD

Ginseng is a root that has been used to treat patients with various illnesses for the last 2000 years. The purpose of this study was to evaluate the effects of Ginseng extract (G115) on Pulmonary Function Tests (PFTs), Maximum Voluntary Ventilation (MVV), Maximum Inspiratory Pressure (MIP) and Maximal Oxygen Consumption (VO2max) in patients with moderately-severe Chronic Obstructive Pulmonary Disease (COPD). Ninety-two adults were randomly divided into the experimental (n = 49, G115 100 mg bid for three months) and placebo-control (n = 43) groups. PFTs, MVV and MIP were studied before treatment and every two weeks for the 3-month-study period. Exercise test and VO2max measurements were performed before the beginning and after six weeks and three months. P lower than 0.05 was considered significant. Baseline demographics and pulmonary parameters were similar between the groups. In the experimental, but not in the control group, all parameters significantly increased above baseline and compared with the placebo group. Maximum increase, compared with baseline was FVC-32.5%, FEV1.0-27.0%, PEF-27.5%, FEF50-45.4%, FEF75-56.9%, MVV-40.4%, MIP-47.0% and VO2max-37.5%. No side effects were observed. G115 100 mg bid for three months, but not placebo, improved PFTs, MVV, MIP and VO2 max in patients with moderately-severe COPD with no side effects.

Activity of matrix metalloproteinase-9 is elevated in sera of patients with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the increased production of autoantibodies and by systemic clinical manifestations and damage to multiple organs. The aim of the present study was to analyse matrix metalloproteinase (MMP)-9 activity in sera of patients with active and inactive SLE in order to evaluate its role in the pathogenesis and course of the disease, as well as its diagnostic value. We measured activity levels of MMP-9 and MMP-2, using both gel zymography and activity assay kits, in sera of 40 SLE patients and of 25 healthy controls. We found that MMP-9 activity, but not MMP-2 activity, is significantly elevated in the sera of SLE patients compared with sera samples of healthy controls. High activity levels of MMP-9 were determined in sera of 68% of the SLE patients. Elevated levels of MMP-9 were correlated with the presence of discoid rash, Raynaud phenomenon, pneumonitis, mucosal ulcers and anti-phospholipid antibodies. Changes in activity levels of MMP-9, but not of MMP-2, were observed in sera of the same patient at different periods of the disease course. High levels of MMP-9 did not correlate with disease activity index (SLEDAI, BILAG) in female patients, but correlated with SLE activity in the group of male patients. The results of the present study suggest that MMP-9 plays a role in the pathogenesis of SLE.

Quantification of relative afferent pupillary defects induced by posterior sub-Tenon's, peribulbar, and retrobulbar anaesthetics

AIMS

The effect of local anaesthetics on optic nerve function can be investigated by quantifying the relative afferent pupillary defect (RAPD).

METHODS

The study compared the depth of induced RAPD following posterior sub-Tenon's, retrobulbar, and peribulbar local anaesthetics using crossed polarising filters before cataract surgery (time 1 = 5 minutes), immediately after surgery (time 2 = 42 minutes (av)), and once again on the ward (time 3 = 107 minutes (av)).

RESULTS

All patients developed a RAPD. There was no significant difference in the depth of RAPD between the groups at any one time period. The peribulbar group had a significantly steeper decay in RAPD from time 1 to time 2 (p = 0.014). This effect was reduced when the shorter operation time for this group was entered as a cofactor (p = 0.063). By time 3 the RAPDs for all groups had decayed similarly so that no differences could be detected.

CONCLUSION

All three anaesthetic methods caused a similar level of disruption to optic nerve conduction immediately following administration and at the time of day case discharge.

Suppression of experimental systemic lupus erythematosus (SLE) in mice via TNF inhibition by an anti-TNFalpha monoclonal antibody and by pentoxiphylline

We have previously shown that the clinical manifestations of experimental systemic lupus erythematosus (SLE) correlate with an early increased secretion of TNFalpha and IL-1. In the present study, we examined the efficacy of two therapeutic modalities which lower TNFalpha production or activity, on the clinical manifestations of the disease. Experimental SLE was induced in naive C3H.SW mice by injection of the human anti-DNA monoclonal antibody (mAb) bearing the common idiotype, 16/6 Id. Two weeks after booster injections, treatment with either an anti-TNFalpha mAb, or pentoxiphylline (PTX) was started, for a period of 6 weeks. Production of TNFalpha (by splenocytes) and IL-1 (by peritoneal macrophages) was determined 3 and 7 months after disease induction. The experimental mice were also followed for disease manifestations. Both treatment protocols, with anti-TNFalpha mAb and with PTX, reduced the production of the two pro-inflammatory cytokines. TNFalpha and IL-1, in mice with experimental SLE. Anti-DNA antibodies were significantly lower in the mice treated with either protocol. In addition, a significantly lower rate of leukopenia, proteinuria and immune complex deposition was observed in treated mice. Abrogation of TNFalpha and IL-1 production in the early stages of experimental SLE by an anti-TNFalpha mAb or by PTX improves the clinical status of mice afflicted with this autoimmune disease.

Clinical comparison of the measurement of the IOP with the ocular blood flow tonometer, the Tonopen XL and the Goldmann applanation tonometer

PURPOSE

In addition to measuring ocular blood flow, the ocular blood flow tonometer (OBF) can also be set to solely record intraocular pressure (IOP). In this mode it provides a quick means of tonometry which may allow nursing staff to be more easily trained in its use than conventional Goldmann tonometry. With a view to its eventual use in nurse-led clinics we undertook a study to compare both the OBF tonometer and our currently favoured nurse practitioners tonometer the tonopen XL with Goldmann tonometry.

METHOD

IOP was measured in 99 eyes with all three tonometers in a random order.

RESULTS

There was not any statistically significant difference between the measurements of all three tonometers.

CONCLUSIONS

It is concluded that OBF tonometer can provide clinically useful measurements of intraocular pressure which may in fact be more accurate than the tonopen, however, our opinion is that it possibly is not suitable for a universal glaucoma clinics application.

The mechanism by which a peptide based on complementarity-determining region-1 of a pathogenic anti-DNA auto-Ab ameliorates experimental systemic lupus erythematosus

A peptide based on complementarity-determining region (CDR)-1 of a monoclonal murine anti-DNA Ab that bears the common idiotype, 16/6Id, was synthesized and characterized. The peptide, designated pCDR1, was found to be an immunodominant T-cell epitope in BALB/c mice. The CDR1-based peptide was shown to be capable of inhibiting the in vivo priming of BALB/c mice immunized with the peptide or with the whole anti-DNA 16/6Id(+) mAbs of either mouse or human origin. We show here that administration of pCDR1 (weekly, i.v., 100 microgram/mouse) in aqueous solution for 5 weeks starting at the time of disease induction with the human 16/6Id prevented the development of clinical manifestations of experimental systemic lupus erythematosus (SLE). Further, 10 weekly injections of pCDR1 to BALB/c mice with an established experimental SLE down-regulated clinical manifestations of SLE (e.g., anti-DNA auto-Abs, leukopenia, proteinuria, immune complex deposits in the kidneys) in the treated mice. Prevention of SLE induction was shown to be associated mainly with a decrease in the levels of IL-2, INFgamma, and the proinflammatory cytokine TNFalpha. On the other hand, the secretion of the immunosuppressive cytokine TGFbeta was elevated. Amelioration of the clinical manifestations of an already established experimental SLE correlated with a dramatic decrease in TNFalpha secretion, elevated levels of TGFbeta, and immunomodulation of the Th1 and Th2 type cytokines to levels close to those observed in healthy mice.

An altered peptide ligand inhibits the activities of matrix metalloproteinase-9 and phospholipase C, and inhibits T cell interactions with VCAM-1 induced in vivo by a myasthenogenic T cell epitope

Myasthenia gravis (MG) is a T cell-regulated, antibody-mediated autoimmune disease. Immunization with two myasthenogenic peptides, p195-212 and p259-271, which are sequences of the human acetylcholine receptor, resulted in MG-associated immune responses. A dual altered peptide ligand (APL) composed of the two APLs of the myasthenogenic peptides inhibited, in vitro and in vivo, those responses. This study was aimed at understanding the mechanism(s) underlying the in vivo inhibitory properties of the dual APL. To this end, we analyzed T cells of mice that were immunized with p259-271 for their adhesiveness toward vascular cell adhesion molecule 1, for the activity of their secreted matrix metalloproteinases (MMPs), and for their intracellular phospholipase C (PLC) activity. Immunization with p259-271 triggered the above three activities and in vivo administration of the dual APL inhibited the latter. Thus, treatment of mice with the dual APL interferes with functions required for T cells to migrate and interact with the self-AChR. This is the first indication that very late antigen 4, MMP-9, and PLC are targets for immunomodulation of autoreactive T cells by altered peptide ligands.

Cytokine profile and T cell adhesiveness to endothelial selectins: in vivo induction by a myasthenogenic T cell epitope and immunomodulation by a dual altered peptide ligand

Myasthenia gravis (MG) is a T cell-regulated antibody-mediated autoimmune disease. Immunization with two myasthenogenic peptides, p195-212 and p259-271, that are sequences of the human acetylcholine receptor alpha subunit was shown to induce experimental autoimmune MG (EAMG)-associated immune responses. A peptide composed of the two altered peptide ligands (APL) of the myasthenogenic peptides (designated as dual APL) inhibited, in vitro and in vivo, those responses. The objectives of this study were to examine (i) whether in vivo T cell activation by p259-271 affects the cytokine profile and the T cell migration ability, and (ii) whether the latter are immunomodulated by in vivo administration of the dual APL. Our results showed that immunization of mice with p259-271 enriched the population of lymph node and spleen cells with subsets of T cells with strong adhesiveness towards E- and P-selectins. This enrichment was associated with an acquisition of a T(h)1-type cytokine profile. Treatment of the immunized mice with the dual APL interfered with both the migratory potential of the autoreactive T cells, and the production of the T(h)1-type cytokines IL-2 and IFN-gamma (known to play a pathogenic role in MG and EAMG). T cells derived from APL-treated mice acquired a T(h)3-type cytokine profile, characterized by the secretion of the immunosuppresive cytokine transforming growth factor-ss. Thus, our results suggest that T cell selectin ligands and T cell-derived cytokines are involved in the induction and immunomodulation of EAMG- and MG-associated T cell responses.

Prospective determination of T-cell responses to S-antigen in Behçet's disease patients and controls

PURPOSE

To prospectively determine, using two different assays, the lymphocyte proliferative response to a retinal autoantigen (S-antigen) in patients with Behçet's disease who are under treatment for ocular inflammation.

METHODS

Patients were evaluated at each visit for signs of ocular inflammation. Peripheral blood leukocytes were harvested and cultured in the presence of bovine S-antigen in a standard culture assay, as well as by limiting dilution using multiple short-term T-cell lines.

RESULTS

Five patients were observed for 2 to 10 months. During follow-up, three patients had episodes of ocular inflammation. No consistent change in proliferative response was observed in standard proliferation assays. However, an increase in established T-cell lines was correlated to the presence of ocular inflammation in all three patients. Ocular activity was associated with an increase of 9- to 30-fold in the frequency of short-term T-cell lines. This increase returned to baseline within 1 to 3 months.

CONCLUSIONS

An increase in S-antigen-responsive lymphocytes is found in the peripheral blood of patients with Behçet's disease during episodes of ocular inflammation. This increase cannot be measured using standard proliferation assays but requires the use of techniques exploiting the principles of limiting dilution analysis.

Immune response of SLE patients to peptides based on the complementarity determining regions of a pathogenic anti-DNA monoclonal antibody

We have examined the humoral and cellular responses of SLE patients to peptides based on the complementarity-determining regions (CDR) of a monoclonal anti-DNA antibody with a major idiotype- 16/6 Id, in comparison to their responses to the whole 16/6 Id-bearing antibody. Sera of 63% of the SLE patients had antibodies that bound the 16/6 Id, 80% had antibodies to one of the CDR-based peptides, and 40% of the patients reacted with both CDRs. Sera of only a few controls reacted with either the 16/6 Id (6%) or the CDR based peptides (4%) (P < 0.01). Peripheral blood lymphocytes (PBL) of 39% of the patients proliferated in response to the 16/6 Id or to one of the CDR-based peptides (37%), while in the control group the proliferation rates were 66% to the 16/6 Id and 59% to one of the CDR-based peptides (P < 0.05). The correlation between (both) the humoral and cellular immune responses to the CDR-based peptides and to the 16/6 Id suggests the relevance of these peptides to the 16/6 Id and provides additional information on the pathogenic moiety of the latter antibody.

A peptide based on the CDR3 of an anti-DNA antibody of experimental SLE origin is also a dominant T-cell epitope in (NZBXNZW)F1 lupus-prone mice

A molecular homology has been demonstrated between sequences of the heavy chain variable regions of the anti-DNA, anti-cardiolipin monoclonal antibody, 2C4C2, isolated from C3H.SW mice with induced systemic lupus erythematosus, and sequences of the anti-DNA monoclonal antibody BW16 originating in the lupus-prone (NZBXNZW)F1 mice. It was of interest to determine whether these homologous sequences function also as immunodominant T-cell epitopes, in order to establish a connection between spontaneous and induced experimental models. Therefore, three peptides were designed and synthesized based on the complementarity determining region (CDR)1, CDR2 and CDR3 of the heavy chain of the monoclonal antibody 2C4C2. In the present study, we compare these peptides with the CDR1- and CDR3-based peptides of another murine anti-DNA antibody; namely, 5G12. The comparison was carried out by analyzing the ability of the peptides to induce T-cell activation in (NZBXNZW)F1 lupus-prone mice and in mouse strains susceptible to induction of experimental systemic lupus erythematosus. Immunization of (NZBXNZW)F1 mice with the 2C4C2 mAb or with its CDR-based peptides, as well as immunization with the 5G12-based CDR peptides, induced significant lymph node proliferation to the pCDR3 of the 5G12 mAb. Naive (NZBXNZW)F1 splenocytes exhibited activation to the same peptide. It is also shown that MHC class II molecules of (NZBXNZW)F1 macrophages bind preferentially the 5G12-based pCDR3. It is proposed that the CDR3-based peptide of 5G12 mAb of experimental lupus is also a dominant and relevant epitope in the (NZBXNZW)F1 lupus-prone mice.

Effect of aging on cytokine production in normal and experimental systemic lupus erythematosus-afflicted mice

Aging mice of strains susceptible to the induction of experimental systemic lupus erythematosus (SLE) develop a milder disease than young animals. To find out whether the decrease in susceptibility to disease is due to age-associated changes in cytokine profile, we first examined the secretion of cytokines by healthy mice aged 2-15 months. A gradual age-related decline in the levels of interleukin (IL)-2 and interferon (IFN) gamma, and an increase in IL-4, IL-10, IL-1, and tumor necrosis factor (TNF) alpha were observed. Experimental SLE was induced in 2- and 10-month-old mice by immunization with the monoclonal anti-DNA antibody bearing the 16/6 Id. Early increased production of pro-inflammatory cytokines (TNFalpha and IL-1), followed by a peak of the Th1-type cytokines (IL-2, IFNgamma) were observed in young mice. The Th2-type cytokines (IL-4, IL-10) peaked later. In contrast, only a mild increase in all of the above cytokines was determined in 10-month immunized mice. It thus appears that the decline in susceptibility to SLE induction in older mice may be related to changes in the capacity to produce cytokines.

Oral administration of a dual analog of two myasthenogenic T cell epitopes down-regulates experimental autoimmune myasthenia gravis in mice

Myasthenia gravis (MG) and experimental autoimmune MG (EAMG) are T cell-regulated, antibody-mediated autoimmune diseases. The major autoantigen in MG is the nicotinic acetylcholine receptor (AChR). Two peptides, representing sequences of the human AChR alpha-subunit, p195-212 and p259-271, were previously shown to be immunodominant T cell epitopes in MG patients as well as, respectively, in SJL and BALB/c mice. A dual analog (termed Lys-262-Ala-207) composed of the tandemly arranged two single amino acid analogs of p195-212 and p259-271 was shown to inhibit, in vitro and in vivo, MG-associated autoimmune responses. Furthermore, the dual analog could down-regulate myasthenogenic manifestations in mice with EAMG that was induced by inoculation of a pathogenic T cell line. In the present study, the ability of the dual analog to treat EAMG induced in susceptible C57BL/6 mice by native Torpedo AChR was evaluated. Mice that were diagnosed to have clinical symptoms of EAMG were treated with the dual analog by oral administration, 500 microg per mouse three times a week for 5-8 weeks. Treatment with the dual analog down-regulated the clinical manifestations of the ongoing disease as assessed by the clinical score, grip strength (measured by a grip strength meter), and electromyography. The effects on the clinical EAMG correlated with a reduced production of anti-AChR antibody as well as a decrease in the secretion of interleukin-2 and, more dramatically, interferon-gamma, in response to AChR triggering. Thus, the dual analog is an efficient immunomodulator of EAMG in mice and might be of specific therapeutic potential for MG.

DNA levels in immune complexes circulating in mice with induced systemic lupus erythematosus

The levels of DNA in IgG immune complexes, which appeared in the circulation of mice after the induction of systemic lupus erythematosus (SLE), were measured by an immunochemical quantitative assay using monoclonal anti-dsDNA antibodies. The amount of DNA in immune complexes was already high at 10-12 days following the injection of a human monoclonal anti-DNA antibody bearing the major idiotype designated 16/6 in complete Freund's adjuvant, i.e. long before the appearance of clinical manifestations. The injections of these antibodies in the alum-precipitated form did not induce the formation of DNA:anti-DNA complexes as well as SLE itself. The levels of DNA in circulating immune complexes were in general high throughout the whole experimental period (up to 7 months) decreasing gradually before the first clinical manifestations appeared and thereafter, when the disease was fully developed. Such a decrease could be explained by the retention of immune complexes in kidneys. The levels of DNA in immune complexes circulating in normal mice or in mice receiving injections of complete Freund's adjuvant was very low. Treatment of experimental SLE that affected the clinical manifestations prevented the formation of high levels of DNA containing immune complexes.

A novel method for the determination of T-cell proliferative responses in patients with uveitis

Standard proliferation assays using autoantigens such as S-Ag have given erratic responses when studied with human peripheral blood mononuclear cells. This erratic response is a reflection of the low number of circulating cells in the peripheral blood capable of generating a response as well as the presence of competing cells for the available cytokines in culture. The present study compares the standard proliferation assay with a novel technique in which multiple short-term cell lines are established to S-Ag in medium enriched in helper cytokines. After 12-14 days of culture, these lines were tested for their response to S-Ag. A significant difference was found between patients and controls in the ability to generate responsive cell lines. This translated to a frequency of responsive cells of 0-4 per 10(7) peripheral blood mononuclear cells (PBMC) in normal individuals and 0-200 per 10(7) PBMC in patients. This novel technique may provide a means of determining the number of responsive cells to specific autoantigens in the peripheral blood of patients and the ability to follow the response over time.

Single amino acid analogs of a myasthenogenic peptide modulate specific T cell responses and prevent the induction of experimental autoimmune myasthenia gravis

Peptide p259-271 of the human acetylcholine receptor alpha-subunit, preferentially stimulates T cells of patients with myasthenia gravis (MG) and is an immunodominant epitope for T cells of BALB/c mice. A p259-271 specific T cell line of BALB/c origin was established and was shown to induce experimental MG in naive mice. Seven analogs of p259-271 were synthesized, and two of them were found to inhibit the p259-271 specific proliferative responses of the line and of p259-271 primed lymph node cells. Moreover, the most efficient inhibitor, analog 262Lys, prevented the MG related manifestations in mice inoculated with the line, and might be of potential value for the treatment of MG.

The role of staphylococcal superantigens in the pathogenesis of marginal keratitis

Previous studies have demonstrated an increased incidence of delayed-type hypersensitivity to staphylococcal antigens in patients with blepharitis, but this does not predict subsequent development of marginal keratitis (MK). Superantigens are potent immune-modifying molecules produced by pathogenic organisms including Staphylococcus aureus. To study whether staphylococcal superantigens play a role in the development of MK, conjunctival and lid margin cultures were taken from 26 subjects with MK and 24 controls. Four of 8 eyes with their first episode of MK grew strains of S. aureus, of which only one was superantigen-producing. None of the subjects with recurrent MK and only one control grew S. aureus. We conclude that staphylococcal superantigens are unlikely to play a central role in the development of MK. The absence of S. aureus on the lids of subjects with recurrent MK may reflect an alteration in lid flora due to previous topical antibiotic and steroid treatment.

Cytokine manipulation by methotrexate treatment in murine experimental systemic lupus erythematosus

OBJECTIVE

We reported beneficial effects of methotrexate (MTX) treatment on clinical variables in the murine model of experimental systemic lupus erythematosus (SLE). We now follow the kinetics of several cytokines that are involved in experimental SLE, to find out whether MTX treatment has an effect on cytokine production.

METHODS

SLE was induced in naive BALB/c female mice by injection of the human monoclonal anti-DNA antibody bearing the common idiotype, 16/6 Id. Six weeks after booster injection, when high levels of autoantibodies were observed, MTX treatment was started (2 mg/kg once a week) for 7 months. Cytokine production by macrophages or splenocytes from these mice was determined monthly by either ELISA or bioassays.

RESULTS

A significant increase in the production of tumor necrosis factor-alpha was determined as early as 2 weeks after injection. Interleukin 1 (IL-1) production increased gradually, starting one month after disease induction. These proinflammatory cytokines reached very high levels that were maintained through disease course. MTX treatment reduced production of these cytokines to normal levels throughout the experimental period. Increased levels of IL-2 and interferon-gamma (IFN-gamma), the Th1 type cytokines, were detected 2-4 months after disease induction. The secretion of the latter then dropped to levels lower than those observed in control mice. Treatment with MTX reversed levels of the cytokines to levels observed in healthy mice, IL-4 and IL-10, the Th2 type cytokines, predominated later in disease course, 5 months after immunization. Two to 3 months later production of IL-4 dropped to levels lower than those of control mice. IL-10 secretion remained higher than in controls throughout the experiment. The production of both IL-4 and IL-10 in MTX treated mice was also similar to that of control mice.

CONCLUSION

The restoration of the cytokine profile to normal levels observed in the MTX treated mice from the initial steps of disease induction suggests its beneficial effects in SLE might be mediated through modulation of cytokine production.

Reactivity of T cells from seronegative patients with myasthenia gravis to T cell epitopes of the human acetylcholine receptor

Seronegative (SN) patients with myasthenia gravis (MG) have clinical and electrophysiologic features similar to those of seropositive (SP) patients, and they respond to the same therapeutic measures. However, because SN patients lack detectable (by standard radioimmunoassays) serum antibodies to acetylcholine receptor (AChR), which are considered to have a crucial role in MG, the pathophysiologic basis for the disease is not clear. We therefore compared the ability of peripheral blood lymphocytes (PBL) of SN patients (11) and SP patients (39) to respond to myasthenogenic T cell epitopes of human AChR. We tested two aspects that relate to T-cell immunity: 1) T cell responses to myasthenogenic peptides by proliferation and IL-2 production, and 2) the ability of antigen-presenting cells to bind these T-cell epitopes. T cells of SN patients did not differ from those of SP patients in their ability to respond and to bind the two human AChR-derived myasthenogenic peptides. This supports the belief that most SN patients indeed suffer from an autoimmune disease directed against the AChR. The presence of T-cell immunity in the absence of antibodies may emphasize the importance of AChR-specific T cells in MG.

Effect of aging on cytokine production in normal and experimental systemic lupus erythematosus afflicted mice

The objective of the this study was to determine the cytokine profile of aging mice and to establish whether changes in cytokine production account for the fact that aging mice develop a milder disease than the young in response to induced experimental systemic lupus erythematosus (SLE). Cytokine secretion was evaluated in groups of BALB/c and C3H.SW mice at different ages between 2 and 24 months. The production of IL-2, IL-4, IL-10, IFN gamma and TNF alpha was determined in supernatants of ConA-stimulated splenocytes and that of IL-1 in the supernatants of LPS-stimulated peritoneal macrophages. A gradual age-related decline was observed in the production of IL-2 and IFN gamma, whereas the levels of IL-4, IL-10, IL-1 and TNF alpha progressively increased with aging, in unimmunized BALB/c and C3H.SW mice. Experimental SLE was induced in 2 and 10 month old C3H.SW mice by immunization with the monoclonal anti-DNA antibody bearing the 16/6 Id. The characteristic cytokine profile following immunization of 2 month old mice was early increased production of TNF alpha and IL-1, followed by a peak of Th1 type cytokines (IL-2, IFN gamma). At a later stage of the disease, a peak of Th2 type cytokines (IL-4, IL-10) was observed that was concomitant with low levels of Th1 cytokines. In contrast, in the 10 month old mice that were immunized with 16/6 Id only a mild increase in all the above cytokines was observed. We suggest that the lower autoantibody production and moderate clinical manifestations in aging mice with experimental SLE are causally related to the decreased production of pro-inflammatory cytokines at the initial stages of the disease followed by a lower production of both Th1 and Th2 type cytokines.

Modulation of murine systemic lupus erythematosus with peptides based on complementarity determining regions of a pathogenic anti-DNA monoclonal antibody

Experimental systemic lupus erythematosus (SLE) can be induced in naive mice by immunization with a murine monoclonal anti-DNA antibody (mAb), 5G12, that bears a major idiotype designated 16/6 Id. Strain-dependent differences were observed in the proliferative responses of lymph node cells of mice immunized with two peptides based on the sequences of the complementarity determining region (CDR) 1 and 3 of mAb 5G12. The capacity of the peptides to bind to major histocompatibility complex class II molecules correlated with the proliferative responses. Immunization of high responder strains with the CDR-based peptides led to production of autoantibodies and clinical manifestations characteristic to experimental SLE. The CDR-based peptides could prevent autoantibody production in neonatal mice that were immunized later either with the peptide or with the pathogenic autoantibody. Furthermore, the peptides inhibited specific proliferation of lymph node cells of mice immunized with the same peptide, with mAb 5G12 or with the human mAb anti-DNA, 16/6 Id. Thus, the CDR-based peptides are potential candidates for therapy of SLE.

A peptide composed of tandem analogs of two myasthenogenic T cell epitopes interferes with specific autoimmune responses

Myasthenia gravis (MG) is a T cell-regulated, antibody-mediated autoimmune disease. Two peptides representing sequences of the human acetylcholine receptor alpha-subunit, p195-212 and p259-271, were previously shown to stimulate peripheral blood lymphocytes of patients with MG and were found to be immunodominant T cell epitopes in SJL and BALB/c mice, respectively. Single amino acid substituted analogs of p195-212 (analog Ala-207) and p259-271 (analog Lys-262) were synthesized. We showed that analogs Ala-207 and Lys-262 inhibited, in vitro and in vivo, the proliferative responses of T cell lines specific to the relevant peptide and lymph node cells of mice immunized to p195-212 and p259-271, respectively. To inhibit T cell responses to both peptides (p195-212 and p259-271), we synthesized dual analogs composed of the tandemly arranged two single (Ala-207 and Lys-262) analogs (dual analog) either sequentially (Ala-207-Lys-262) or reciprocally (Lys-262-Ala-207). In the present study, we report that both dual analogs could bind to major histocompatibility complex class II molecules on antigen-presenting cells of SJL and BALB/c mice. Analog Lys-262-Ala-207, which bound more efficiently to major histocompatibility complex class II molecules, was found to inhibit the proliferative responses of both p195-212- and p259-271-specific T cell lines. Furthermore, the analog inhibited the in vivo priming of lymph node cells of both SJL and BALB/c mice when administered i.v., i.p., or per os. The dual analog Lys-262-Ala-207 could also immunomodulate myasthenogenic manifestations in mice with experimental autoimmune MG induced by inoculation of a pathogenic T cell line. Thus, a single peptide that is composed of analogs to two epitope specificities can be used to regulate T cell responses and disease associated with each epitope.

Kinetics of cytokine production in experimental systemic lupus erythematosus: involvement of T helper cell 1/T helper cell 2-type cytokines in disease

We followed cytokine production from induction through disease progression in a murine model of experimental systemic lupus erythematosus (SLE). SLE was induced by immunization with the human monoclonal anti-DNA Ab that bears the common Id designated 16/6 Id. BALB/c and C3H.SW mice that are susceptible to SLE induction and C57BL/6 mice that are resistant were immunized with the 16/6 Id. Cytokine production was tested periodically for 7 mo. Increased production of IL-2 and IFN-gamma, the Th1-type cytokines, was detected in BALB/c and C3H.SW mice 2 to 4 mo following immunization. IL-4 and IL-10, the Th2-type cytokines predominated later in disease course, and peaked 5 mo following disease induction. At this stage the Th1 type cytokines dropped to levels below those observed in controls. IL-4 production also dropped rapidly to very low levels, while IL-10 production decreased but remained above control levels. The ratio of IgG2a/IgG1 of DNA and 16/6 Id-specific Abs peaked at 2 mo following disease induction and decreased later, in concordance with the higher production of Th2-type cytokines. Thus, the development of experimental SLE in mice involves two stages: increased production of Th1-type, followed by increased induction of Th2-type cytokines. High levels of the proinflammatory cytokines, TNF-alpha and IL-1, were maintained throughout disease course. No significant changes were detected in the cytokine profile of C57BL/6 immunocytes following immunization with the 16/6 Id, supporting the possible role of the cytokine network in SLE.

Kinetics of cytokine production in experimental systemic lupus erythematosus: involvement of T helper cell 1/T helper cell 2-type cytokines in disease

We followed cytokine production from induction through disease progression in a murine model of experimental systemic lupus erythematosus (SLE). SLE was induced by immunization with the human monoclonal anti-DNA Ab that bears the common Id designated 16/6 Id. BALB/c and C3H.SW mice that are susceptible to SLE induction and C57BL/6 mice that are resistant were immunized with the 16/6 Id. Cytokine production was tested periodically for 7 mo. Increased production of IL-2 and IFN-gamma, the Th1-type cytokines, was detected in BALB/c and C3H.SW mice 2 to 4 mo following immunization. IL-4 and IL-10, the Th2-type cytokines predominated later in disease course, and peaked 5 mo following disease induction. At this stage the Th1 type cytokines dropped to levels below those observed in controls. IL-4 production also dropped rapidly to very low levels, while IL-10 production decreased but remained above control levels. The ratio of IgG2a/IgG1 of DNA and 16/6 Id-specific Abs peaked at 2 mo following disease induction and decreased later, in concordance with the higher production of Th2-type cytokines. Thus, the development of experimental SLE in mice involves two stages: increased production of Th1-type, followed by increased induction of Th2-type cytokines. High levels of the proinflammatory cytokines, TNF-alpha and IL-1, were maintained throughout disease course. No significant changes were detected in the cytokine profile of C57BL/6 immunocytes following immunization with the 16/6 Id, supporting the possible role of the cytokine network in SLE.

The effectiveness of topical diclofenac in relieving discomfort following traumatic corneal abrasions

Diclofenac is a non-steroidal anti-inflammatory drug available in an ophthalmic preparation. We present a prospective randomised double-masked placebo-controlled trial involving 40 patients that assessed the effectiveness of topical diclofenac in relieving pain from traumatic corneal abrasions. Statistical analysis of visual analogue and categorical pain scores revealed a significant reduction in pain experienced by subjects in the diclofenac group (p < 0.02).

The beneficial effects of treatment with tamoxifen and anti-oestradiol antibody on experimental systemic lupus erythematosus are associated with cytokine modulations

In an attempt to elucidate the role of oestrogens in systemic lupus erythematosus (SLE) we investigated the effects of treatment with an oestrogen antagonist-tamoxifen and a monoclonal anti-oestradiol (anti-E2) antibody on mice in which experimental systemic lupus erythematosus (SLE) was induced by a human monoclonal anti-DNA antibody bearing the 16/6 idiotype (16/6 Id). Thus, groups of BALB/c female mice were immunized with the 16/6 Id and 3 weeks following the booster injection, when antibody titres were elevated in the injected mice, treatment protocols with anti-oestradiol or tamoxifen were initiated. Control groups that were not immunized with the 16/6 Id but were similarly treated with the above agents were included in the study. The treatment with the above agents had no effect on the total autoantibody titres; however, a decrease in the immunoglobulin G (IgG)2a/IgG1 ratio of the anti-DNA antibodies was determined in the 16/6 Id immunized and treated mice. Further both the anti-oestradiol and tamoxifen had beneficial effects on the clinical manifestations (white blood cell counts, levels of protein in the urine and immune complex deposits in the kidneys) of the 16/6 Id immunized and treated mice. We have previously observed a significant elevation in interleukin-1 (IL-1) and tumour necrosis factor-alpha (TNF-alpha) secretion in mice with experimental SLE and a reduction in IL-2, IL-4 and interferon-gamma (INF-gamma) levels as compared with the levels detected in healthy controls. Treatment with either the anti-oestradiol antibody or with tamoxifen restored the levels of all the above cytokines to the normal levels observed in the control mice. These findings suggest that cytokine modulation may be the basis for the therapeutic effects of both anti-oestrogens in experimental SLE.

Acute angle closure glaucoma masquerading as systemic illness

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Peptide analogs to pathogenic epitopes of the human acetylcholine receptor alpha subunit as potential modulators of myasthenia gravis

Myasthenia gravis is an autoimmune disease in which T cells specific to epitopes of the autoantigen, the human acetylcholine receptor, play a role. We identified two peptides, p195-212 and p259-271, from the alpha subunit of the receptor, which bound to major histocompatibility complex (MHC) class II molecules on antigen-presenting cells (APCs) from peripheral blood lymphocytes of myasthenia gravis patients and stimulated lymphocytes of >80% of the patients. We have prepared analogs of these myasthenogenic peptides and tested their ability to bind to MHC class II determinants and to interfere specifically with T-cell stimulation. We first determined relative binding efficiency of the myasthenogenic peptides and their analogs to APCs of patients. We found that single substituted analogs of p195-212 (Ala-207) and p259-271 (Lys-262) could bind to human MHC molecules on APCs as efficiently as the original peptides. Moreover, dual analogs containing the two single substituted analogs in one stretch (either sequentially, Ala-207/Lys-262, or reciprocally, Lys-262/Ala-207) could also bind to APCs of patients, including those that failed to bind one of the single substituted analogs. The single substituted analogs significantly inhibited T-cell stimulation induced by their respective myasthenogenic peptides in >95% of the patients. The dual analogs were capable of inhibiting stimulation induced by either of the peptides: They inhibited the response to p195-212 and p259-271 in >95% and >90% of the patients, respectively. Thus, the dual analogs are good candidates for inhibition of T-cell responses of myasthenia gravis patients and might have therapeutic potential.

Binding of peptides of the human acetylcholine receptor alpha-subunit to HLA class II of patients with myasthenia gravis

MG is an autoimmune disease in which T cells specific to T-cell epitopes of the human acetylcholine receptor play a role. We have identified two peptides, p195-212 and p259-271, of the human acetylcholine receptor alpha-subunit, to which PBLs of MG patients responded by proliferation. Nevertheless, proliferation assays are relatively complicated to perform and might be affected by medications taken by the patients. Therefore, we tested the possibility of using a different assay to determine recognition of these peptides by MG patients. Thus, we performed a direct binding assay using biotinylated peptides and APCs from peripheral blood of MG patients and healthy controls. With this assay we detected the binding of the two peptides to the surface of intact APCs of both MG patients and control donors. Moreover, the presentation of peptide p259-271 by individuals with MG was significantly higher than that observed in healthy subjects. The peptides were specifically bound to HLA class II determinants on the APCs, as shown by inhibition with antibodies to the HLA class II haplotypes of the individuals investigated. Moreover, the binding of these peptides was in correlation with their ability to induce specific proliferative responses of peripheral blood T cells of these patients. The ability to screen for potentially pathogenic epitopes in each patient is of importance for the future design of specific inhibitory analogues that might be used to treat MG.

Methotrexate treatment in murine experimental systemic lupus erythematosus (SLE); clinical benefits associated with cytokine manipulation

The objective of this study was to determine the effects of Methotrexate (MTX) on the development and the course of experimental murine SLE, as well as on the cytokine profile involved in the disease. SLE was induced in naive BALB/c female mice by injection of the human anti-DNA MoAb bearing a common idiotype (16/6 Id). Six weeks following immunization, when high levels of autoantibodies were demonstrated, the mice were treated with MTX (2 mg/kg once a week) for a period of 10 months. MTX treatment had no effect on 16/6 Id-induced autoantibody production. However, MTX treatment had beneficial effects on the clinical manifestations of the experimental disease (i.e. leucocyte counts, levels of protein in the urine and immune complex deposits in the kidneys). Thus, only 20% of 16/6 Id-immunized BALB/c mice that were treated with MTX had immune complex deposits in their kidneys compared with 100% of SLE-afflicted BALB/c mice that were not treated. We have observed a significant elevation in IL-1, tumour necrosis factor (TNF) and IL-10 secretion in BALB/c mice afflicted with experimental SLE. IL-2, IL-4, IL-6 and interferon-gamma (INF-gamma) levels were decreased in these mice compared with the levels detected in healthy controls. Treatment with MTX reversed the levels of all the above cytokines to normal levels observed in control mice. These studies demonstrate therapeutic effects of MTX on murine experimental SLE. The normal cytokine profile observed following treatment with MTX is suggested to play a role in the amelioration of the clinical manifestations of experimental SLE.