Rose Anne Leakan

Differentiation of human bone marrow-derived cells into buccal epithelial cells in vivo: a molecular analytical study

BACKGROUND Adult bone marrow-derived (BMD) cells could be used to repair damaged organs and tissues, but the intrinsic plasticity of these cells has been questioned by results of in-vitro studies suggesting that such cells might fuse with other cells giving the appearance of differentiation. We aimed to determine whether fusion events are important in vivo. METHODS To test whether BMD cells can colonise an epithelial tissue and differentiate there without fusion, we did in-situ hybridisation with Y and X chromosome probes labelled with 35-sulphur or digoxigenin, or labelled fluorescently. We did immunohistochemistry with anticytokeratin 13 along with fluorescence in-situ hybridisation to identify Y-chromosome positive buccal epithelial cells in cheek scrapings obtained from five females who had received either a bone-marrow transplant or an allogeneic mobilised peripheral-blood progenitor-cell transplant (enriched in CD34+ cells) from male donors. FINDINGS When examined 4-6 years after male-to-female marrow-cell transplantation, all female recipients had Y-chromosome-positive buccal cells (0.8-12.7%). In more than 9700 cells studied, we detected only one XXXY-positive cell (0.01%) and one XXY cell (0.01%), both of which could have arisen when an XY cell fused with an XX cell. INTERPRETATION Male BMD cells migrate into the cheek and differentiate into epithelial cells, an occurrence that does not depend on fusion of BMD cells to recipient cells. This finding might be an example of transdifferentiation of haemopoietic or stromal progenitor cells. Plasticity of BMD cells could be useful in regenerative medicine.

Lack of efficacy of etanercept in Sjögren syndrome correlates with failed suppression of tumour necrosis factor α and systemic immune activation

Objective: To provide insight into the clinical failure of the tumour necrosis factor α (TNFα) inhibitor, etanercept, in primary Sjögren syndrome (pSS), an extensive analysis of the systemic immune profile of patients with pSS was carried out and the effect of etanercept treatment on these immune parameters monitored. Methods: Peripheral blood mononuclear cells of patients with pSS and healthy controls were compared by flow cytometry to determine differences in distribution of specific cell populations (T cells, B cells, monocytes), and to determine their expression of activation markers (CD25, HLA-DR), TNF receptors and chemokine receptors (CXCR1, 2) before and after treatment. Systemic cytokine levels were measured by multiplex ELISA assay in plasma and in lipopolysaccharide-stimulated whole blood from healthy controls and from patients with pSS before and after etanercept treatment. Baseline cytokine levels were correlated with clinical markers of disease. Results: Before treatment, salivary gland inflammatory focus scores did not correlate with circulating TNF levels. Furthermore, consistent with the lack of evidence of significant clinical benefit, enhanced markers of immune activation, frequency of cell subpopulations and aberrant cytokine profiles were not restored to normal levels by etanercept treatment. Remarkably, the levels of circulating TNFα were significantly increased after treatment. Conclusion: Etanercept is an ineffective therapeutic agent in pSS consistent with the absence of suppression of TNFα and other indicators of immune activation in this patient population. These data suggest that TNFα may not be a pivotal cytokine in the pathogenesis of pSS, impelling continued molecular characterisation of disease parameters to define appropriate intervention targets.

Fungal load and candidiasis in Sjögren’s syndrome

OBJECTIVE We sought to investigate the prevalence of Candida carriage and the relationships between salivary flow rates and oral Candida load in patients with Sjögrens syndrome (SS). METHODS The oral Candida load of patients with SS was evaluated by culturing oral rinse (swish and spit) samples. Culture, Gram stain, and wet-mount test results were reported. RESULTS One hundred three patients (96 women) met European criteria for SS (91 with primary SS and 12 with secondary SS). The mean age (95% confidence interval) was 55 years (range, 51-57 years). Oral rinse cultures were positive in 77% of subjects. The total stimulated salivary flow rate was inversely correlated with oral Candida load (r = -0.47; P </=.0001). The oral rinse samples yielded gram-positive results in 38% of patients with SS, and the Fungi-Fluor assay (wet mount) results were positive in 49%. CONCLUSIONS The prevalence of Candida carriage varies according to the methods used to determine the presence of the organism and is similar to that reported in the literature. A low stimulated salivary flow rate-not a low unstimulated flow rate-was associated with Candida carriage.

Lack of efficacy of etanercept in Sjögren’s syndrome correlates with failed suppression of TNFα and systemic immune activation

Objective: To provide insight into the clinical failure of the tumour necrosis factor α (TNFα) inhibitor, etanercept, in primary Sjögren syndrome (pSS), an extensive analysis of the systemic immune profile of patients with pSS was carried out and the effect of etanercept treatment on these immune parameters monitored. Methods: Peripheral blood mononuclear cells of patients with pSS and healthy controls were compared by flow cytometry to determine differences in distribution of specific cell populations (T cells, B cells, monocytes), and to determine their expression of activation markers (CD25, HLA-DR), TNF receptors and chemokine receptors (CXCR1, 2) before and after treatment. Systemic cytokine levels were measured by multiplex ELISA assay in plasma and in lipopolysaccharide-stimulated whole blood from healthy controls and from patients with pSS before and after etanercept treatment. Baseline cytokine levels were correlated with clinical markers of disease. Results: Before treatment, salivary gland inflammatory focus scores did not correlate with circulating TNF levels. Furthermore, consistent with the lack of evidence of significant clinical benefit, enhanced markers of immune activation, frequency of cell subpopulations and aberrant cytokine profiles were not restored to normal levels by etanercept treatment. Remarkably, the levels of circulating TNFα were significantly increased after treatment. Conclusion: Etanercept is an ineffective therapeutic agent in pSS consistent with the absence of suppression of TNFα and other indicators of immune activation in this patient population. These data suggest that TNFα may not be a pivotal cytokine in the pathogenesis of pSS, impelling continued molecular characterisation of disease parameters to define appropriate intervention targets.

Layered Peptide Arrays: High-Throughput Antibody Screening of Clinical Samples

High-throughput methods to detect and quantify antibodies in sera and other patient specimens have use for many clinical and laboratory studies, including those associated with cancer detection, microbial exposures, and autoimmune diseases. We developed a new technique, termed layered peptide array (LPA), to serve as a screening tool to detect antibodies in a highly multiplexed format. We demonstrate here that a prototype LPA was capable of producing approximately 5000 measurements per experiment and appeared to be scalable to higher throughput levels. Sera and saliva from Sjögrens syndrome patients served as a test set to examine antibody titers in clinical samples. The LPA platform exhibited both a high sensitivity (100%) and high specificity (94%) for correctly identifying SSB antigen-positive samples. The multiplex capability of the platform was also confirmed when serum and saliva samples were analyzed for antibody reactivity to several peptides, including Sjögrens syndrome antigens A and B. The data indicate that LPA analysis will be a useful method for a number of screening applications.

Adult heart block is associated with disease activity in primary Sjögren's syndrome

Objectives: Congenital heart block occurring in the foetus and neonate may be associated with maternal anti‐SS‐A/anti‐SS‐B autoantibodies (anti‐SSA/anti‐SSB). The adult atrioventricular node is generally thought to be resistant to the damaging effects of anti‐SSA/anti‐SSB. However, case reports suggest that heart block developing in adult Sjögrens syndrome (SS) patients may be associated with these autoantibodies. Therefore, we investigated the relationship between serum antibodies and heart block in adult SS patients. Methods: We abstracted data from clinic patient records. Diagnosis of primary SS was based on American–European classification criteria. Electrocardiograms (EKGs), laboratory immunology parameters, lipid profiles, and focus scores from labial salivary gland biopsies were available for 51 SS patients. Fifteen patients had follow‐up EKGs. PR interval⩾200 ms was considered to be first‐degree heart block. Results: Five patients showed prolonged PR intervals; the presence of heart block was not related to the presence of anti‐SSA antibodies. However, significant differences between patients with prolonged and normal PR intervals were seen for mean focus scores (p<0.0001), anti‐cardiolipin immunoglobulin IgG (p = 0.0009), age (p = 0.01), IgG (p = 0.02), anti‐SSB antibodies (p = 0.02), and high density lipoprotein (HDL) cholesterol levels (p = 0.03). These parameters correlated with prolonged PR intervals. Conclusions: These results suggest an association between disease activity, the presence of anti‐SSB antibodies, and the occurrence of first‐degree heart block in adults with primary SS.