Red blood cell distribution width as a surrogate biomarker of damage and disease activity in patients with systemic lupus erythematosus.

OBJECTIVES: Red blood cell distribution width (RDW) is a measure of variability in mean corpuscular volume. Alterations in RDW can be observed in a variety of human disorders, including inflammatory, cardiovascular, and hepatic or renal diseases. Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that can affect virtually any organ in the body. In this work, our objective was to analyse how a complete characterisation of disease characteristics in a large series of patients with SLE is related to RDW values. METHODS: 284 patients with SLE and 181 age- and sex-matched healthy controls were recruited. Complete blood count including RDW was assessed. Multivariable analysis was performed to analyse the relationship between RDW and SLE disease characteristics, including composite scores of disease activity and damage. RESULTS: After multivariable adjustment, RDW was higher in patients with SLE compared to controls (beta coefficient 0.8 [95% confidence interval: 0.3-1] %, p=0.003). Several disease characteristics, such as the presence of extractable nuclear antibodies and antiphospholipid syndrome, and the use of prednisone and azathioprine, were significantly associated with higher levels of RDW after adjustment for confounders. Of note, cumulative disease damage and disease activity scores were associated with higher RDW values after controlling for covariates. CONCLUSIONS: RDW may serve as a surrogate biomarker of accrual disease damage and activity in patients with SLE.

Blood Composite Scores in Patients with Systemic Lupus Erythematosus.

Complete blood count-derived ratios have been described as inflammatory biomarkers in several diseases. These hematological scores include the neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammatory index ([SIRI]; neutrophils × monocytes/lymphocytes). Our aim was to study how these biomarkers are related to disease expression in a large and well-characterized series of patients with systemic lupus erythematosus (SLE). A total of 284 SLE patients and 181 age- and sex-matched healthy controls were recruited. The NLR, MLR, PLR, and SIRI were calculated, and activity (SLEDAI-2K), severity (Katz), and damage index (SLICC-DI) scores were assessed in patients with SLE. Multivariable linear regression analysis was performed to study whether these scores differ between patients and controls and how they are related to clinical and laboratory features of the disease. Crude cell counts of neutrophils, monocytes, lymphocytes, and platelets were lower in SLE patients compared to controls. Despite this, NLR, MLR, and PRL, but not SIRI, were higher in SLE patients than in controls after multivariable analysis. However, the relationship between the different scores and disease characteristics was limited. Only the Katz severity index revealed a significant positive relationship with SIRI, NLR, and MLR after adjustment for covariates. Similarly, alternative complement cascade activation and low C3 were significantly associated with higher NLR, MLR, and PLR. In conclusion, although cytopenias are a common feature of patients with SLE, hematologic composite scores are independently higher in this population compared to controls. However, the relationship of these scores with the characteristics of the disease is scarce, with the relationship with the complement system being the most consistent.

Relationship between Disease Characteristics and Circulating Interleukin 6 in a Well-Characterized Cohort of Patients with Systemic Lupus Erythematosus.

Interleukin-6 (IL-6) is a proinflammatory cytokine that mediates pleiotropic functions in immune responses and inflammatory diseases. The literature lacks studies, with a clinical perspective, on the relationship between IL-6 serum levels and the characteristics of the disease in patients with systemic lupus erythematosus (SLE). In the present work, we aimed to analyze the association between circulating IL-6 and disease manifestations in a well-characterized series of patients with SLE. Serum IL-6 levels and disease activity (SLEDAI-2K), severity (Katz) and damage index (SLICC-DI), complete lipid profile, and subclinical carotid atherosclerosis were evaluated in 284 patients with SLE. In addition, a complete characterization of the complement system was performed in samples from patients with SLE. A multivariate linear regression analysis was carried out to study the relationship between clinical and laboratory characteristics of the disease and IL-6 levels. Age (beta coef. 0.07 [95%CI 0.01-0.1] pg/mL, p = 0.014), C-reactive protein (beta coef. 0.21 [95%CI 0.16-0.25] pg/mL, p < 0.01), and male gender (beta coef. 2 [95%CI 0.3-0.5] pg/mL, p = 0.024), were positively associated with higher IL-6 levels in SLE patients. Most disease characteristics and damage and activity indices did not show significant relationships with IL-6. However, after multivariate analysis, IL-6 was associated with lower serum levels of HDL cholesterol (beta coef. -0.04 [95%CI -0.08-(-0.1)] pg/mL, p = 0.011), and apolipoprotein A1 (beta coef. -0.02 [95%CI -0.04-(-0.001)] pg/mL, p = 0.035). In contrast, the alternative complement cascade, C1inh, and C3a were all positively and independently associated with higher serum levels of IL-6. Moreover, stratification of the Systematic Coronary Risk Assessment 2 (SCORE2) results according to different categories of cardiovascular risk was associated with higher circulating serum IL-6 levels (beta coef. 0.2 [95%CI 0.02-0.4], pg/mL, p = 0.028). In conclusion, in a large series of SLE patients, IL-6 was not associated with disease-related features of SLE, including damage, severity, or activity indices. However, an association was found between serum IL-6 levels and circulating C3a and cardiovascular risk. Our study emphasizes the importance that IL-6 could have in cardiovascular disease and complement system disruption of SLE patients. Therapies targeting IL-6 could have a role in these two clinical manifestations of patients with SLE.

Short Brown Parallel Lines on the Proximal Nail Fold. Clinical-Dermoscopic-Histologic Correlation of a Melanocytic Nevus of the Eponychium.

Introduction: Although Hutchinson's sign can appear associated with benign conditions, dermoscopic findings of non-melanoma eponychium pigmentation have not yet been described in the literature. We report for the first time to our knowledge the dermoscopic findings of an acral nevus located in the proximal nail fold as well as its clinical-dermoscopic-histologic correlation. Case Report: A twenty-year-old patient presented with a homogeneous longitudinal melanonychia on the left-hand thumb, with benign dermoscopic pattern, and an irregular, 6-mm, dark-brown hyperpigmented macule on the adjacent eponychium (Hutchinson's sign). The eponychium lesion showed on dermoscopy two irregular brown-black pigmented blotches, with superimposed parallel brown lines on a brushy distribution, with a thicker terminal end. The histopathologic examination of the proximal nail fold was performed, revealing scattered nevus cells in the epidermal basal layer and dermal-epidermal junction thecae, without any atypia or mitosis. These features were consistent with nevus of the proximal nail fold. Discussion: Previous descriptions of benign hyponychium's pigmentations, despite the malignant appearance of the overlying melanonychia, were reported to have a similar dermoscopic pattern, known as longitudinal brushy pigmentation. This newly described dermoscopic sign on the eponychium may help distinguish Hutchinson's sign related to subungual melanoma to non-melanoma Hutchinson's sign.