Background/Purpose:  Recent studies suggest that a platelet α-granule protein named TREM-like transcript-1 (TLT-1) is a key molecule in modulating the inflammatory response. TLT-1 has been proposed to be an inhibitor of the inflammatory gene activator TREM-1 and its soluble ligand, thus preventing overactivation of the immune cellular response and sustained inflammation. TLT-1 plasma levels are markedly elevated in infectious disorders such as sepsis and dengue to counterbalance the inflammatory response. The role of TLT-1 in systemic lupus erythematosus (SLE) is unknown. Thus, the aims of this study were to assess TLT-1 plasma levels in SLE patients and healthy individuals, and to determine the factors associated with TLT-1 levels among SLE patients.

Methods:  A cross-sectional, case-control study was performed in 46 SLE patients (per American College of Rheumatology [ACR] criteria) and 28 healthy individuals. Data on demographic parameters, clinical manifestations (ACR and non ACR lupus manifestations), disease activity (as per the Systemic Lupus Activity Measure [SLAM]), health-related quality of life (using the Lupus Patient Reported Outcome [LupusPRO] questionnaire), comorbidities, pharmacologic treatment, and damage accrual (as per the Systemic Lupus International Collaborating Clinics/ ACR Damage Index) were gathered. Plasma TLT-1 levels were measured by ELISA. Student’s t test (or Wilcoxon signed-rank test, as appropriate) and Pearson’s correlation coefficient test were used for statistical analysis.

Results:  The mean (standard deviation [SD]) age for SLE patients and healthy individuals was 45.5 (11.8) and 37.3 (12.1) years respectively; 93% of SLE patients and controls were females. The mean disease duration (SD) of SLE patients was 10.7 (4.1) years. SLE patients had lower mean (SD) levels of plasma TLT-1 than controls (9.0 [7.2] vs. 18.6 [22.3] ng/ml, p=0.008). A negative correlation was observed between TLT-1 levels and the SLAM (r = -0.278, p 0.064) and some domains of LupusPRO (lupus symptoms [r = -0.388, p = 0.055], cognition [r = -0.442, p = 0.027], physical health [r = -0.382, p = 0.060], desires/goals [r = -0.435, p = 0.030]). SLE patients receiving corticosteroid treatment had higher mean (SD) levels of TLT-1 than those not taking corticosteroids (11.1 [8.8] vs. 6.9 [4.6] ng/ml, p = 0.014).

Conclusion:  Plasma levels of TLT-1 were lower in SLE patients compared to healthy individuals. Among SLE patients a negative correlation was observed for disease activity and some domains of the LupusPRO. Given that TLT-1 has anti-inflammatory properties, deficiency of this protein could have an important role in the pathogenesis of SLE.

---

« Back to 2013 ACR/ARHP Annual Meeting

ACR Meeting Abstracts - https://acrabstracts.org/abstract/association-of-trem-like-transcript-1-with-systemic-lupus-erythematosus/