Anti-inflammatory effects of infliximab and methotrexate on peripheral blood and synovial fluid mononuclear cells: ex vivo study

OBJECTIVE

To investigate the effects of methotrexate (MTX) and the tumour necrosis factor inhibitor infliximab (IFX) on immune cells derived from peripheral blood mononuclear cells (PBMCs) and synovial fluid mononuclear cells (SFMCs) of inflammatory arthritis patients.

METHOD

Phytohaemagglutinin (PHA)-induced proliferation of healthy donors' PBMCs and synovial intermediate monocytes (CD14+CD16+ cells) in SFMCs derived from psoriatic arthritis (PsA) and rheumatoid arthritis (RA) patients was determined by flow cytometry following co-culture with IFX and MTX. PHA-induced interferon-γ (IFN-γ) production in PBMCs was measured by enzyme-linked immunosorbent assay. The drugs' effect on mRNA expression in SFMCs was determined by quantitative polymerase chain reaction.

RESULTS

The combination of IFX 10 μg/mL + MTX 0.1 μg/mL had the strongest inhibitory effect on PBMC proliferation (91%), followed by MTX 0.1 μg/mL (86%) and IFX 10 μg/mL (49%). In PHA-stimulated PBMCs, IFN-γ production was reduced by IFX 10 μg/mL, MTX 0.1 μg/mL, and IFX 10 μg/mL + MTX 0.1 μg/mL by 68%, 90%, and 85%, respectively. In SFMCs, IFX 10 µg/mL significantly reduced CD14+CD16+ cells compared to medium (PsA 54%, p < 0.01; RA 46%, p < 0.05), while MTX had no effect on this population. IFX + MTX led to a similar suppression of CD14+CD16+ cells as achieved by IFX alone. The drugs had different impacts on SFMC gene expression.

CONCLUSION

Both IFX and MTX effectively inhibited PBMC proliferation and IFN-γ production, but only IFX reduced synovial monocytes and pro-inflammatory gene expression in SFMCs, suggesting a differential impact of IFX and MTX on critical inflammatory cell populations ex vivo.

AB0312 INCREASED PREVALENCE OF OBSTRUCTIVE SLEEP APNEA IN INDIVIDUALS WITH SYSTEMIC LUPUS ERYTHEMATOSUS

Background:

Sleep disturbances are common in individuals with rheumatological diseases in general and systemic lupus erythematosus (SLE) in particular1. Studies suggest that obstructive sleep apnea (OSA) might correlate with SLE disease activity and the presence of additional symptoms such as pain, fatigue, affective symptoms and steroid use2. Sleep disturbances symptomatology such as fatigue and increased pain overlap with constitutional inflammatory symptoms of SLE and may mimic or mask disease related relapse3,4. Therein lies the importance of diagnosing and treating such disorders in SLE.

Objectives:

To determine whether patients with SLE have increased prevalence of OSA as assessed by the apnea hypopnea index (AHI) and to explore possible contributors to OSA including SLE disease activity and accrued damage, medications, secondary fibromyalgia and depression.

Methods:

42 consecutive patients with SLE (38 women, 4 men) and 20 healthy, sex, body mass index (BMI) and age matched controls (15 women, 5 men) were consecutively recruited and underwent an ambulatory sleep study using the WatchPAT device. All participants completed questionnaires including Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), Functional Assessment of Chronic Illness Therapy (FACIT), Widespread Pain Index (WPI), Symptoms Severity Scale (SSS) and Beck Depression Inventory. SLE disease activity and damage were assessed using the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) and Systemic Lupus International Collaborating Clinics (SLICC) damage index.

Results:

The mean AHI was 9.19 ± 6.79 in the SLE group and 3.95 ± 3.47 in the control group (p=0.004). Moderate-severe OSA (AHI≥15) was significantly more common in patients with SLE (23.6% vs. 0%, p=0.04). Patients with SLE had lower sleep efficiency (83.38 ± 6.15 vs. 87.22 ± 4.24, p=0.03), increased sleep arousals (7.72 ± 5.66 vs. 5.13 ± 2.29, p=0.01), higher PSQI and FACIT scores SLE (8.14 ± 3.47 vs. 5.10 ± 2.64, p=0.001, 16.89 ± 11.19 vs. 7.29 ± 5.93, p= 0.0008 respectively) and had more fibromyalgia as assessed by WPI and SSS (19.5% vs. 0%, p=0.04). BMI and the SLICC score were independent predictors of OSA (p=0.03 and p=0.02 respectively). A correlation between SLEDAI and moderate-severe OSA was found (p=0.03), although an association to medications, secondary fibromyalgia and depression was not found.

Conclusion:

Patients with SLE have increased prevalence of OSA with lower sleep quality compared to healthy controls. Our findings suggest a possible correlation between accrued damage as assessed by the SLE damage index and OSA.

References:

[1]Wu, L., Shi, P. L., Tao, S. S., Tao, J. H. & Wu, G. C. Decreased sleep quality in patients with systemic lupus erythematosus: a meta-analysis. Clin. Rheumatol. (2020) doi:10.1007/s10067-020-05300-3.

[2]Palagini, L. et al. Sleep disorders and systemic lupus erythematosus. Lupus vol. 23 115–123 (2014).

[3]Javaheri, S. & Javaheri, S. Update on Persistent Excessive Daytime Sleepiness in OSA. Chest vol. 158 776–786 (2020).

[4]Mertz, P. et al. Towards a practical management of fatigue in systemic lupus erythematosus. Lupus Science and Medicine vol. 7 (2020).

Table 1.

WatchPAT sleep parameters analysis

SLE groupn = 42Control groupn = 20P valueRDI ± SD13.52 ± 6.549.72 ± 3.600.04AHI ± SD9.19 ± 6.793.95 ± 3.470.004ODI ± SD2.54 ± 2.721.27 ± 1.450.04Sleep efficiency (%) ± SD83.38 ± 6.1587.22 ± 4.240.03Number of arousals ± SD7.72 ± 5.665.13 ± 2.290.01Saturation (%) ± SD96.10 ± 1.3795.75 ± 1.390.45Sleep latency ± SD21.25 ± 9.3318.46 ± 6.630.27REM latency ± SD87.88 ± 49.0673.60 ± 46.210.09REM ± SD25.35 ± 14.0327.32 ± 6.790.15Light sleep ± SD57.63 ± 12.3752.70 ± 11.630.18Deep sleep ± SD17.89 ± 5.5918.76 ± 6.700.54

SLE, Systemic Lupus Erythematosus; RDI, Respiratory Disturbance Index; SD, Standard Deviation; AHI, Apnea Hypopnea Index; ODI, Oxygen Desaturation Index; REM Rapid Eye Movement.

Disclosure of Interests:

None declared

Impaired diffusion tensor imaging findings in the corpus callosum and cingulum may underlie impaired learning and memory abilities in systemic lupus erythematosus

BACKGROUND

Memory impairment is prevalent in systemic lupus erythematosus (SLE); however, its pathogenesis is unknown. In a previous functional magnetic resonance imaging (fMRI) study we demonstrated altered brain activity dynamics and less brain deactivation in patients with SLE as compared with healthy controls, when performing a learning and memory task. Our findings localized this impairment to the default mode network (DMN), and particularly to its anterior medial prefrontal cortex node. In addition, altered networking of the hippocampal subsystem of the DMN was seen in patients with SLE when performing this task, as well as atrophy of the left hippocampus. The present study aimed to search for a structural substrate for the altered recruitment pattern observed in fMRI studies using diffusion tensor imaging (DTI).

PATIENTS AND METHODS

Using DTI, we characterized brain diffusivity in 10 patients with SLE and nine healthy controls. Two tracts associated with the DMN were reconstructed: the corpus callosum (CC) and the cingulum bundle. The CC was segmented according to the Witelson segmentation scheme and the cingulum was segmented into superior and descending bundles.

RESULTS

A significant increase in mean diffusivity (MD) was seen in patients with SLE without neuropsychiatric SLE (NPSLE) as compared with healthy controls in all five segments of the CC (segment 1: p = 0.043; segment 2: p = 0.005; segment 3: p = 0.003; segment 4: p = 0.012; segment 5: p = 0.023) as well as in the descending portion of the left cingulum bundle (p = 0.026).

CONCLUSIONS

Increased MD values in the CC and the left cingulum may indicate impaired organization/reduced integrity of these tracts, which may underlie the abnormal pattern of brain activity recruitment of the DMN observed during a verbal learning and memory task. Taking into account the central role of the left hippocampus in verbal memory, the abnormal integrity of the left cingulum may contribute to the reduced performance of patients with SLE on verbal memory tasks.

QuantiFERON-TB Gold in the identification of latent tuberculosis infection in rheumatoid arthritis: a pilot study

OBJECTIVE

To compare the performance of QuantiFERON-TB Gold (QFT-G) with that of the tuberculin skin test (TST) in detecting latent tuberculosis (LTBI) among patients with rheumatoid arthritis (RA).

PATIENTS AND METHODS

A total of 35 RA patients and 15 healthy controls underwent TST, QFT-G assays and chest X-ray and filled out a questionnaire on predisposing conditions for TB disease. Serum interferon gamma (IFN-gamma) levels were tested by an enzyme-linked immunosorbent assay.

RESULTS

Forty-five per cent of RA patients had a TST > 5 mm vs. 26% in healthy controls. In the RA patients, QFT-G was positive in 11.4%, negative in 60% and indeterminate in 28.6%. The overall agreement between TST and QFT-G was significantly lower in the RA population than in controls (56% vs. 84%). No correlation was found between the use of prednisone, methotrexate and QFT-G results or agreement between TST and QFT-G. A low IFN-gamma level (<4 pg/ml) was found in 51.5% of the RA patients. No correlation was found between serum IFN-gamma levels and QFT-G results.

CONCLUSION

The clinical significance of negative QFT-G in TST-positive patients with low TB risk remains to be assessed. The high rate of indeterminate results questions the clinical utility of QFT-G in the diagnosis of LTBI in RA patients.

[Gamma hydroxy butyrate intoxication]

Gamma Hydroxybutirate (GHB) is unfamiliar to many physicians in Israel. Recently GHB has emerged as an illicit drug of misuse for its purported euphoric and aphrodisiac effect. The clinical effects can progress rapidly to respiratory arrest and death. We provide a description of a case of GHB poisoning, with a comprehensive review of the literature emphasizing the pharmacodynamics, clinical effect, and suggestions for management. Physicians are urged to become familiar with GHB.