Autoantibodies to protein transport and messenger RNA processing pathways: endosomes, lysosomes, Golgi complex, proteasomes, assemblyosomes, exosomes, and GW bodies

Over 50 years ago the lupus erythematosus (LE) cell phenomenon was described and this was quickly followed by the introduction of the LE cell test and indirect immunofluorescence (IIF) to detect antinuclear antibodies (ANA) in clinical laboratories. Recently, attention has turned to the identification of the autoantigens that bind to cytoplasmic organelles such as the Golgi complex, endosomes and other "cytoplasmic somes". Three endosome autoantigens include early endosome antigen 1 (EEA1, 160 kDa), cytoplasmic linker protein-170 (CLIP-170, 170 kDa), and lysobisphosphatidic acid (LBPA). Antibodies to EEA1 were seen in a variety of conditions but approximately 40% of the patients had a neurological disease. Despite the prominence of lysosomes in cells and tissues, reports of autoantibodies are limited to the lysosomal antigen h-LAMP-2 and the cytoplasmic antineutrophil antibodies (cANCA). Autoantigens in the Golgi complex include giantin/macrogolgin, golgin-245, golgin 160, golgin-97, golgin 95/gm130, and golgin-67. More recently, there has been an interest in autoantibodies that bind components of the "SMN complex" or the "assemblyosome". Arginine/glycine (RG)-rich domains in components of the SMN complex interact with Sm, like-Sm (LSm), fibrillarin, RNA helicase A (Gu), and coilin proteins, all of which are antigen targets in a variety of diseases. More recently, components of a novel cytoplasmic structure named GW bodies (GWBs) have been identified as targets of human autoantibodies. Components of GWBs include GW182, a unique mRNA-binding protein, like Sm proteins (LSms), and decapping (hDcp1) and exonuclease (Xrn) enzymes. Current evidence suggests that GWBs are involved in the cytoplasmic processing of mRNAs. Autoantibodies to the "cytoplasmic somes" are relatively uncommon and serological tests to detect most of them are not widely available.     

Synthesis of the Gln1-facteur thymique serique and its evaluation with human E-rosette bioassay

Synthesis of an analog of facteur thymique serique (FTS) containing a glutaminyl residue in position 1 of the peptide chain is described. Like the original FTS, Gln¹-FTS is able to induce T cell markers on lymphocytes in vitro in a picogram dosage range. The human E-rosette bioassay was adopted for the evaluation of biological activity of Gln¹-FTS. It was also shown that the latter method can be used to evaluate the presence of target cells for FTS activity in peripheral blood lymphocytes in humans.     

117例系统性红斑狼疮患者ANA、抗ENA抗体、抗dsDNA抗体检测

目的:探讨ANA、抗dsDNA、抗ENA多肽抗体谱联合检测在SLE的诊断中应用。方法:ANA、抗ds-DSDNA采用间接免疫荧光法;抗ENA多肽抗体采用免疫印迹法。结果:117例病人中ANA84例,阳性率为71.8%、抗dsDNA22例,阳性率为18.8%、抗Sm26例,阳性率为22.2%、抗SSA72例,占61.5%。结论:ANA、抗ENA、抗ds-DSDNA的联合检测可避免因单项检测而出现的漏诊情况,在SLE的诊断中具有互补性,有利于提高SLE的检出率。     

IV Consenso Brasileiro para pesquisa de autoanticorpos em células HEp-2

ObjectiveThe Fourth Brazilian Consensus for Autoantibodies Screening in HEp-2 Cells (ANA) was held in Vitória, Espírito Santo, and aimed to discuss strategies and recommen- dations about the technique, standardization, interpretation and quality control of the indirect immunofluorescence reaction on HEp-2 cells.MethodsTwenty three ANA experts from university centers and private laboratories in different areas from Brazil discussed and agreed upon recommendations for the fourth edition of the Brazilian Consensus for Autoantibodies Screening in HEp-2 Cells.Results and conclusionThe 4 th ANA Consensus included three novel patterns into the existing algorithm (cytoplasmic Rods and Rings, nuclear Quasi-homogeneous, and CENPF). Emphasis was given to the need of attention in describing the peculiar mixed pat- tern elicited by anti-DNA topoisomerase I (Scl-70) autoantibodies, comprising nuclear fine specked, nucleolar homogeneous pattern, NOR staining in metaphase plates, and cytoplasmic fine speckled patterns. The group also emphasized the need for continuous quality control in indirect immunofluorescence assays, the establishment of screening dilutions, as well as conjugate titration. An alert was made regarding the heterogeneity of commercial kits in defining patterns and the use of solid phase methodologies to deter- mine the presence of autoantibodies.     

Deleting the BAFF receptor TACI protects against systemic lupus erythematosus without extensive reduction of B cell numbers

B cell-activating factor of the TNF family (BAFF) is an essential B cell survival factor. However, high levels of BAFF promote systemic lupus erythematosus (SLE) in mice and humans. Belimumab (anti-human BAFF) limits B cell survival and is approved for use in patients with SLE. Surprisingly, the efficacy of rituximab (anti-human CD20) in SLE remains controversial, despite depleting B cells more potently than belimumab. This raises the question of whether B cell depletion is really the mechanism of action of belimumab. In BAFF transgenic mice, SLE development is T cell-independent but relies on innate activation of B cells via TLRs, and TLR expression is modulated by the BAFF receptor TACI. Here, we show that loss of TACI on B cells protected against BAFF-mediated autoimmune manifestations while preserving B cells, suggesting that loss of BAFF signaling through TACI rather than loss of B cells may underpin the effect of belimumab in the clinic. Therefore, B cell-sparing blockade of TACI may offer a more specific and safer therapeutic alternative to broad B cell depletion in SLE.     

Use of panel testing for detection of antinuclear antibody in a resource-limited setting: an appraisal

Objectives: Despite an increase in the incidence of systemic connective tissue diseases (CTD), panel testing for detection of antinuclear antibodies (ANA) is not a routine practice in many health centers of the Indian subcontinent. Consequently, the data on its significance is scanty.

Methods: To evaluate utility of panel testing, line immunoassay (LIA) and indirect immunofluorescence antinuclear antibody test (IIF-ANA) were performed in 321 cases of CTD.

Results: Out of 321 serum samples screened by the above tests, 227 were positive and 18 were negative by both LIA and IIF-ANA. Additional 11/321 (3.4%) cases were picked up by LIA. SSA was most common specificity in these cases followed by SSA/SSB, SSB, Ro-52, Jo-1, dsDNA and nRNP/Sm.

Conclusion: Use of LIA along with IF-ANA and ELISA improves sensitivity of CTD screening.     

Differential development of behavioral tolerance and the subsequent hedonic effects of alcohol in AA and ANA rats

RATIONALE: There at least two ways in which tolerance development to alcohol's behavioral effects could interact with its subsequent intake: 1) tolerance to alcohol's reward or reinforcing effects per se could lead to increased consumption, and 2) tolerance to alcohol's aversive effects could unmask alcohol's rewarding effects. These two mechanisms may differentially interact with preexisting genetic traits underlying alcoholism. OBJECTIVES: Alcohol's subjective attributes were assessed in selectively bred AA and ANA rats after the development of tolerance to alcohol's behaviorally disruptive effects on lever-press performance. METHODS: Rats were trained to press a lever under an FR30 schedule of food presentations. Group-dependent differential access to intoxicated practice, using a typical pre-post drug administration design, was utilized to promote the development of alcohol tolerance in only the group receiving intoxicated practice sessions. Subsequently, rats were trained to associate alcohol with unique place and taste stimuli in order to assess the relative changes in the approach towards, or avoidance of alcohol-related cues in each group. RESULTS: Groups of AA and ANA rats given access to intoxicated practice demonstrated tolerance development. These groups subsequently conditioned place preferences and failed to develop conditioned taste aversions to alcohol. Passive alcohol exposure in the ANA rats set the occasion for the development of a place preference and delayed taste conditioning. AA rats exposed to passive alcohol exposure failed to condition place preferences and developed rapid taste aversions. Saline control rats failed to develop tolerance or place preferences but did condition a robust alcohol-induced taste aversion. CONCLUSIONS: AA and ANA rats differ in their behavioral and pharmacokinetic response to chronic alcohol exposure. Compensatory responses interacting with approach-avoidance behaviors appear to be learned during intoxicated practice in the AA rats and during both intoxicated practice and passive exposure in the ANA rat line.     

Lack of increased prevalence of immunoregulatory disorders in hereditary angioedema due to C1-inhibitor deficiency

Hereditary angioedema due to deficiency of C1-INH (HAE-C1-INH) is associated with enhanced consumption of the early complement components, which may predispose for autoimmune disease.We assessed the prevalence of such disorders among HAE- C1-INH patients and their impact on the natural course of HAE-C1-INH.Clinical data and immunoserological parameters of 130 HAE-C1-INH and 174 non-C1-INH-deficient patients with angioedema were analyzed.In our study, the incidence of immunoregulatory disorders was 11.5% in the population of HAE-C1-INH patients and 5.2% among non-C1-INH-deficient controls with angioedema. Immunoserology screening revealed a greater prevalence of anticardiolipin IgM (p = 0.0118) among HAE-C1-INH patients, than in those with non-C1-INH-deficient angioedema.We did not find higher prevalence of immunoregulatory disorders among our HAE-C1-INH patients. However, in patients with confirmed immunoregulatory disorders, the latter influenced both the severity of HAE-C1-INH and the effectiveness of its long-term management. Appropriate management of the immunoregulatory disease thus identified improves the symptoms of HAE-C1-INH.     

抗核抗体阴性的大疱性系统性红斑狼疮1例

报告１例抗核抗体阴性的大疱性系统性红斑狼疮。在整个病程中共查过７次抗核抗体均阴性。ＤＩＦ、ＩＩＦ，免疫印迹均无阳性发现。肾脏穿刺活检免疫荧光见ＩｇＧ颗粒状沉积。并讨论其诊断依据和大疱性系统性红斑狼疮抗核抗体为阴性的可能原因。