Prévalence et valeur diagnostique des anticorps antinucléaires de spécificité antigénique indéterminée : étude rétrospective à propos d’une série de 90 patients

Purpose

The objective of this study was to determine the clinical relevance and the diagnostic significance of positive antinuclear antibodies (ANA) without identified antigenic target by the usual characterization technique.

Patients and methods

Retrospective study conducted in the Laboratory of Immunology of Habib Bourguiba Hospital (Sfax, Tunisia) during 18 months. The inclusion criteria were the presence of an ANA titer greater or equal to 1/320 with negative characterization result. ANA screening was performed by indirect immunofluorescence (IIF) on Hep2 cells. Each positive serum was tested by IIF on Crithidia luciliae (anti-native DNA) and by immunodot (anti-nucleosome, anti-histone, anti-Sm, anti-RNP, anti-SSA, anti-SSB, anti-Scl 70, anti-PM-Scl, anti-Jo1, anti-PCNA and anti-ribosomal protein). Sera of systemic lupus erythematosus (SLE), myositis, and scleroderma patients were tested for anti-Ku, anti-PL7, anti-PL12 and anti-Ro-52 using dot myositis.

Results

Sera of 90 patients were studied: 18 men and 72 women (average age: 44 years). Drug-induced ANA was found in eight patients. The most frequent clinical symptoms were joint (56.7%), cutaneous (54.4%) and constitutional symptoms (45.6%). The diagnosis of an autoimmune disease was suspected in 49 patients (54.5%) and confirmed in 30 (33.3%) including 20 cases of connective tissue disease: myositis (n = 6), scleroderma (n = 5), Sjögren's syndrome (n = 3), SLE (n = 4), rheumatoid arthritis (n = 6) and antiphospholipid syndrome (n = 4). Other autoimmune diseases were less frequent. The anti-Ku antibody was detected in the majority of patients with connective tissue disease. The diagnosis of non-autoimmune diseases was established in 25.5% of patients. Eighteen patients (20%) had no diagnosis orientation.

Conclusion

Our study demonstrated the diagnostic value of the presence of ANA even in the absence of known antigenic target, confirmed the role of the IIF as “gold standard” test for ANA screening, and suggested the usefulness of the addition of Ku antigen in the immunodot classic profile.     

Elevated seminal protein carbonyl concentration is correlated with asthenozoospermia and affects adversely the laboratory intracytoplasmic sperm injection (ICSI) outcomes

Elevated concentrations of reactive oxygen species (ROS) in the semen can lead to oxidative protein damage as they react with the amino acids' side chains in the protein, leading to the generation of carbonyl groups. This study aimed to investigate the effect of protein carbonyl (PC) concentration on sperm motility and the laboratory intracytoplasmic sperm injection (ICSI) outcomes. A total of 150 couples from the ICSI cycle were enrolled in this study and were divided into three groups (G) according to the PC concentration as following, G1 included samples with PC concentrations <0.65 nmol/mg, G2 included samples with 0.65≤PC≤2.23 nmol/mg and G3 included samples with PC>2.23 (nmol/mg). PC concentrations were measured in all semen samples, and the laboratory ICSI outcomes were evaluated for all injected oocytes. The Kruskal–Wallis p-values for the differences in the medians of sperm motility, fertilisation rate, embryo cleavage score and embryo quality score were <0.05. Furthermore, Dunn's post hoc test showed a significant difference between all groups, p-values <0.05, except for the medians of embryo quality score between G2 and G3. In conclusion, our results showed that sperm motility and laboratory ICSI outcomes are affected negatively by higher concentrations of PC in the semen.     

Unbalanced inherited complex chromosome rearrangement involving chromosome 8, 10, 11 and 16 in a patient with congenital malformations and delayed development

Complex chromosome rearrangements (CCR) are rare structural chromosome aberrations that can be found in patients with phenotypic abnormalities or in phenotypically normal patients presenting, however, recurrent miscarriages or infertility. Conventional karyotype generally allows their identification. However, molecular cytogenetic methods can reveal subtle rearrangements. We report, here, the identification of an unbalanced maternally inherited CCR in a boy with multiple congenital malformations and delayed development. High-resolution karyotype completed by molecular cytogenetic prompted us to precise the rearrangements. The healthy mother was found to carry a balanced de novo CCR that implicates four chromosomes (8, 10, 11 and 16), six breakpoints, three translocations and an insertion. The malsegregation of this CCR had led, in her son, to partial 10p12.3 to 10p14 deletion, a chromosomal region associated with the DiGeorge like phenotype.     

Mycobacterium abscessus and M. avium trigger Toll-like receptor 2 and distinct cytokine response in human cells

Mycobacterium avium (MAV) and M. abscessus (MAB) are ubiquitous environmental organisms increasingly recognized to cause chronic lung disease in patients with apparently normal immune function. Little is yet known about their human pathophysiology. Our objective was to examine cytokine and chemokine responses (protein and gene expression) and signaling pathways triggered by reference and clinical isolates of MAB and MAV in human peripheral blood mononuclear cells, monocytes, and murine bone marrow-derived macrophages in vitro. MAB-induced TNF-alpha production was higher than that induced by MAV. IFN-gamma, IL-1beta, and the chemokines macrophage inflammatory protein-1alpha and regulated on activation, normal T cell expressed and secreted were equally up-regulated. Differences between MAB and MAV do not require replication and are heat stable. We found no differential effect due to rough or smooth colonies within the same species. Similar to MAV, MAB triggered mitogen-activated protein kinase (MAPK) signaling and nuclear factor-kappaB translocation. Induction of TNF-alpha was dependent on MAPK pathways, since pre-incubation of cells with signaling inhibitors led to more than 85% reduction in cytokine secretion. MAB also triggered a Toll-like receptor 2 (TLR2)-mediated response that led to TNF-alpha production by human monocytes. Accordingly, stimulation of murine TLR2- or myeloid differentiation factor 88-deficient bone marrow-derived macrophages did not elicit TNF-alpha, reinforcing a critical role for TLR2 in MAB-induced cell activation. We concluded that MAB signals human cells through MAPK and TLR2 pathways and triggers more pronounced pro-inflammatory cytokines and chemokines than MAV.     

Chronic lithium administration triggers an over-expression of GRP94 stress protein isoforms in mouse liver

Moderate doses of lithium were chronically administered to mice in order to verify whether the cytoprotective effects of lithium could be in part attributed to a molecular protection conferred by stress proteins/chaperones accumulation. In order to reach serum lithium levels within the common therapeutic values, mice were fed for 6 months on food pellets contained 1 g (L1 group) or 2 g (L2 group) lithium carbonate/kg, resulting in serum concentrations of 0.5 and 0.9 mM Li, respectively. Under these experimental conditions, no clinical side-effects were observed. Urea and creatinine concentrations in serum, lipids peroxidation level and activities of catalase, superoxide-dismutase and glutathione-peroxidase in liver and kidney were not significantly different from control values. Although the expression level of the constitutive HSP73 was not significantly modified, HSP72 was found to be down-regulated in kidney after 1 month. In liver, three protein bands were immunodetected by the anti-GRP94 antibody: 98 kDa and 96 kDa proteins corresponding to more or less glycosylated forms and/or phosphorylated forms of GRP94 and a 80 kDa protein probably being a cleavage product of GRP94. The 96 kDa and 80 kDa proteins were significantly up-regulated in liver of lithium-treated mice as compared to controls.     

Non‐recurrent laryngeal nerve and arteria lusoria: Rare and little known association

Non‐recurrent Laryngeal nerve is constantly associated with Arteria Lusoria. Knowing this association is the basis of predicting this condition preoperatively. Ultrasonography assessment before thyroid and parathyroid surgery should include identification of brachiocephalic trunk division. Absence of its visualization indicates Arteria Lusoria and then non‐recurrent laryngeal nerve.