Ferritin in the antiphospholipid syndrome and its catastrophic variant (cAPS)

BACKGROUND

Ferritin is an iron storage protein considered also as an acute phase reactant with high levels in various inflammatory conditions. Recently, a plausible role for ferritin in the pathogenesis of immune-mediated and especially autoimmune diseases has been suggested. However, the link between ferritin and the antiphospholipid syndrome (APS) has been rarely explored. Therefore, in the current study we evaluated ferritin levels and their correlation to clinical and serological manifestations in patients with APS. We further analyzed ferritin levels among patients with the catastrophic variant of APS (cAPS).

METHODS

Ferritin levels were determined in serum samples of 176 APS patients and 98 matched healthy controls according to age and sex (LIAISON, DiaSorin, Italy). APS samples were further analyzed for antiphospholipid (anti-cardiolipin, anti- beta-2-glycoprotein, lupus anticoagulant) and anti-infectious antibodies (CMV, EBV, rubella, toxoplasma, HBV) (LIAISON, DiaSorin, Italy). Clinical, serological and demographic manifestations were recorded. An additional analysis of ferritin levels among 14 patients with cAPS was performed.

RESULTS

Hyperferritinemia was present in 9% vs. 0% of APS patients and controls, respectively (p < 0.001). Among patients with APS, ferritin levels correlated with venous thrombosis, cardiac, neurological, and hematological manifestations and the presence of anti-CMV-IgM antibodies. Hyperferritinemia was present in 71% of cAPS patients, and ferritin levels among this subgroup were significantly higher compared with APS-non-cAPS patients (816 ± 847 ng/ml vs. 120 ± 230 ng/ml, p < 0.001).

CONCLUSIONS

Herein, we found that hyperferritinemia correlates with the presence of APS, its clinical manifestations and specifically with the catastrophic variant of this disease. Hyperferritinemia was also linked with anti-CMV antibodies among patients with APS. These associations allude to a pathogenic role of ferritin in the pathogenesis of APS, and the plausible role of ferritin as a marker of ensuing cAPS, although further studies are needed to elucidate these associations.

When APS (Hughes syndrome) met the autoimmune/inflammatory syndrome induced by adjuvants (ASIA)

Vaccination of healthy individuals is the most effective approach to protect the public from infections and prevent the spread of many infectious diseases all over the globe. Licensed vaccines are mostly safe, but in rare cases they may be associated with humoral response to self-antigens due to molecular mimicry, epitope spread, bystander activation or polyclonal triggering. Moreover, the clinical picture of autoimmune conditions following post-vaccination is rarer. Nevertheless, anecdotal case reports on the flare of autoimmune response with clinical manifestations were reported. Herein, we discuss this topic in relation to post-vaccination-induced antiphospholipid antibodies following tetanus toxoid vaccine, HBV and influenza associated in rare cases with antiphospholipid syndrome clinical manifestations. We will discuss the possible mechanisms which pertain to ASIA (Shoenfeld syndrome).

Adjuvant immunization induces high levels of pathogenic antiphospholipid antibodies in genetically prone mice: another facet of the ASIA syndrome

Adjuvants may induce autoimmune diseases in susceptible individuals, a phenomenon recently defined as autoimmune/inflammatory syndrome induced by adjuvants (ASIA). Patients with both antiphospholipid antibodies (aPL) and the genetic coagulopathy factor V Leiden (FVL) are frequently found. We therefore evaluated whether adjuvant can induce aPL in heterozygous FVL mice. aPL were measured in naïve mice and at 1 and 5 months after immunization with either complete or incomplete Freund's adjuvant (CFA, IFA) in FVL and control C57/B6 background mice. We defined antibody levels 3 SD above the mean of C57/B6 mice immunized with adjuvant as positive (specificity of 99%). For β(2)GPI-dependent aPL, 28.6% (6/21) of FVL mice 5 months after immunization with adjuvant (both IFA and CFA) were positive compared with 4.8% (1/22) of FVL mice 1 month after adjuvant and 0% of naïve FVL and C57/B6 mice (0/16, p < 0.001). aPL levels correlated with behavioral hyperactivity in the staircase test. FVL mice immunized with adjuvant did not develop β(2)GPI-independent aPL. We hypothesize that the FVL aPL association is not a coincidence, but that chronic coagulation defects combined with external inflammatory stimuli analogous to adjuvant may induce aPL and also antiphospholipid syndrome, thus supporting the notion of ASIA.

Cap-assisted colonoscopy (CAC) significantly extends visualization in the right colon

BACKGROUND

Although colonoscopy is the standard procedure in the diagnosis of colorectal neoplasia, a significant number of clinically relevant lesions may be missed even by experienced endoscopists using current technology. Particular problems may occur with blind spots behind the semilunar folds and within the right colon. A transparent cap mounted at the tip of a colonoscope may be an easy way to extend the visual field during colonoscopy and may improve the detection rate of mucosal lesions. However, data in the literature are controversial and the quantity of the potential extension of visualization by a transparent cap has not been reported yet.

MATERIAL AND METHODS

The significance of cap-assisted colonoscopy (CAC) to increase visualization within different colonic segments (rectum, sigmoid colon, descending colon, transverse colon, ascending colon, cecum) was quantitatively analyzed by randomized back-to-back colonoscopies with and without cap. The investigations were performed in a colonic training model by 5 investigators. The inner colonic surface was stained by a raster of dots and the number of dots counted during colonoscopy served as a measure for the visible surface area of each segment.

RESULTS

The time to advance the colonoscope to the respective colonic segments and the overall time to reach the cecum were not significantly different between conventional and CAC. In contrast, overall withdrawal time and withdrawal times for the cecum, ascending colon, descending colon and rectum were significantly longer for CAC, but not for the transverse and sigmoid colon. Visualization of the colonic surface was significantly increased during CAC. Overall, 59.76 ± 2.70 % of the maximal countable dots were visualized without cap and 85.36 ± 9.62 % with cap. The improvement of visualization was only significant for the right colon, but not for the rectum, sigmoid or descending colon.

CONCLUSION

The finding of the present study suggests that the extension of visualization by CAC may be of particular value for the right colon.

Matrix algorithms for solving (in)homogeneous bound state equations

In the functional approach to quantum chromodynamics, the properties of hadronic bound states are accessible via covariant integral equations, e.g. the Bethe-Salpeter equation for mesons. In particular, one has to deal with linear, homogeneous integral equations which, in sophisticated model setups, use numerical representations of the solutions of other integral equations as part of their input. Analogously, inhomogeneous equations can be constructed to obtain off-shell information in addition to bound-state masses and other properties obtained from the covariant analogue to a wave function of the bound state. These can be solved very efficiently using well-known matrix algorithms for eigenvalues (in the homogeneous case) and the solution of linear systems (in the inhomogeneous case). We demonstrate this by solving the homogeneous and inhomogeneous Bethe-Salpeter equations and find, e.g. that for the calculation of the mass spectrum it is as efficient or even advantageous to use the inhomogeneous equation as compared to the homogeneous. This is valuable insight, in particular for the study of baryons in a three-quark setup and more involved systems.

Prolactin’s role in the pathogenesis of the antiphospholipid syndrome

Increased levels of serum prolactin have been reported in patients with various autoimmune diseases and have been associated with lupus disease activity. Currently, there is a lack of data regarding hyperprolactinaemia in patients with the antiphospholipid syndrome. Hence, this study was carried out in order to evaluate the prevalence and clinical significance of hyperprolactinaemia in antiphospholipid syndrome. A total of 172 European patients with antiphospholipid syndrome and 100 geographically and sex-matched healthy controls were included in the study; none had obvious causes of hyperprolactinaemia. All patients underwent clinical assessment for disease manifestations, in addition to laboratory assessment for serum prolactin, antiphospholipid antibodies and some other biomarkers of autoimmune diseases. The tests were performed utilizing the LIAISON® Analyzer (DiaSorin, Sallugia Italy). Hyperprolactinaemia was detected in 21/172 patients with antiphospholipid syndrome and 0/100 controls (p < 0.001). This significant difference was present in both genders and was obvious even after subgrouping the patients into primary and secondary antiphospholipid syndrome. When clinical features were compared, hyperprolactinaemia was associated with reproductive failure, including early and late pregnancy loss (p < 0.05), as well as intrauterine growth retardation (p < 0.05). Hyperprolactinaemia was negatively related to arthralgias, venous thrombosis, pulmonary microthrombosis, pulmonary hypertension in both primary antiphospholipid syndrome and antiphospholipid syndrome secondary to other diseases, and to neurological manifestations in primary antiphospholipid syndrome (p<0.05). The data indirectly imply that prolactin may play a role in the pathogenesis of antiphospholipid syndrome, especially antiphospholipid syndrome-related reproductive failure.

Vitamin D: an instrumental factor in the anti-phospholipid syndrome by inhibition of tissue factor expression

BACKGROUND AND AIMS

Antiphospholipid syndrome (APS) is a systemic autoimmune disease characterised by thrombosis, obstetric complications and the presence of anti-phospholipid antibodies such as anti-β2GPI-Abs. These antibodies may set off the coagulation cascade via several mechanisms, including the induction of tissue factor (TF) expression. Vitamin D has recently emerged as an immunomodulator that might exert an anti-thrombotic effect. Therefore, we studied serum vitamin D levels in a cohort of APS patients, as well as the effect of vitamin D in an in vitro model of APS-mediated thrombosis.

METHODS

Serum vitamin D levels were measured in 179 European APS patients and 141 healthy controls using the LIAISON chemiluminescent immunoassay, and the levels were evaluated in conjunction with a wide spectrum of clinical manifestations. In an vitro model, anti-β2GPI antibodies were purified from four patients with APS to evaluate the expression of TF in activated starved human umbilical vein endothelial cells. The effect of vitamin D (1,25-dihydroxyvitamin D, 10 nm) on anti-β2GPI-Abs mediated TF expression was analysed by immunoblot.

RESULTS

Vitamin D deficiency (serum level ≤15 ng/ml) was documented in 49.5% of our APS patients versus 30% of controls (p<0.001) and was significantly correlated with thrombosis (58% vs 42%; p<0.05), neurological and ophthalmic manifestations, pulmonary hypertension, livedo reticularis and skin ulcerations. In vitro vitamin D inhibited the expression of TF induced by anti-β2GPI-antibodies.

CONCLUSIONS

Vitamin D deficiency is common among APS patients and is associated with clinically defined thrombotic events. Vitamin D inhibits anti-β2GPI-mediated TF expression in vitro. Thus, vitamin D deficiency might be associated with decreased inhibition of TF expression and increased coagulation in APS. Evaluation of vitamin D status and vitamin D supplementation in APS patients should be considered.

Efficacy of intravenous immunoglobulin (IVIG) affinity-purified anti-desmoglein anti-idiotypic antibodies in the treatment of an experimental model of pemphigus vulgaris

Pemphigus vulgaris is a rare life-threatening autoimmune bullous disease caused by immunoglobulin G (IgG) autoantibodies directed against desmogleins 1 and 3. Previously, we showed that intravenous immunoglobulin (IVIG) ameliorates anti-desmoglein-induced experimental pemphigus vulgaris in newborn naive mice. The aim of this study was to examine the efficacy of anti-anti-desmoglein-specific IVIG in a similar model. Pemphigus-vulgaris-specific IVIG (PV-sIVIG) was affinity-purified from IVIG on a column of single-chain variable fragment (scFv) anti-desmogleins 1 and 3. The anti-idiotypic activity of PV-sIVIG was confirmed by enzyme-linked immunosorbent assay, inhibition assay. After induction of pemphigus by injection of anti-desmogleins 1 and 3 scFv to newborn mice, the animals were treated with PV-sIVIG, IVIG (low or high dose) or IgG from a healthy donor (n = 10 each). The skin was examined 24-48 h later, and samples of affected areas were analysed by histology and immunofluorescence. In vitro study showed that PV-sIVIG significantly inhibited anti-desmogleins 1 and 3 scFv binding to recombinant desmoglein-3 in a dose-dependent manner. Specificity was confirmed by inhibition assay. In vivo analysis revealed cutaneous lesions of pemphigus vulgaris in mice injected with normal IgG (nine of 10 mice) or low-dose IVIG (nine of 10 mice), but not in mice treated with PV-sIVIG (none of 10) or high-dose IVIG (none of 10). On immunopathological study, PV-sIVIG and regular IVIG prevented the formation of acantholysis and deposition of IgG in intercellular spaces. In conclusion, the PV-sIVIG preparation is more effective than native IVIG in inhibiting anti-desmoglein-induced pemphigus vulgaris in mice and might serve as a future therapy in patients with the clinical disease.

The embryotoxicity of sera from patients with autoimmune diseases on post-implantation rat embryos in culture persists during remission and is not related to oxidative stress

We evaluated the embryolethality and embryotoxicity of sera from patients suffering from autoimmune diseases during remission on post-implantation rat embryos cultured on these sera and determined the association between the patients' clinical history, high blood levels of specific antibodies, medications, and oxidative stress parameters. One hundred and eighty, 10.5-day-old rat embryos were cultured in their yolk sacs in 33 sera of systemic lupus erythematosus (SLE)/antiphospholipid syndrome (APS) patients, and compared with 84 embryos cultured in rat sera and 88 embryos cultured in control human sera. The sera proved to be lethal and embryotoxic but not teratogenic resulting in smaller yolk sacs and embryos, lower protein level and lower developmental score. Significantly less embryos cultured in 'toxic' SLE/APS sera had peak 2 of low molecular weight antioxidants (LMWA) wave, implying a delayed maturation of the antioxidant defense. Lower peak 1 of LMWA correlated with a history of recurrent abortions. Embryonic levels of superoxide dismutase (SOD) and catalase (CAT) did not correlate with sera toxicity, patients' clinical history or specific antibodies. We conclude that SLE/APS patients' clinical remission did not prevent death or developmental delay accompanied by later appearance of peak 2 of LMWA in post-implantation rat embryo cultures. The normal levels of the antioxidant enzymes evaluated may indicate that sera toxicity is not related to oxidative stress.

Molecular mimicry in systemic lupus erythematosus

Systemic lupus erythematosus is a multi-systemic autoimmune disease distinguished by the presence of various autoantibodies. Like most autoimmune diseases, systemic lupus erythematosus is believed to be induced by a combination of genetic, immunologic, and environmental factors, mainly infectious agents. Molecular mimicry between an infectious antigen and self-components is implicated as a pivotal mechanism by which autoimmune diseases such as systemic lupus erythematosus are triggered. Here we review the current evidence of molecular mimicry between different infectious agents and systemic lupus erythematosus.

Infectious antibodies in systemic lupus erythematosus patients

Infections can act as environmental triggers that induce or promote systemic lupus erythematosus (SLE) in genetically predisposed individuals. New technologies, developed recently, enable simultaneous assessment of multiple antibodies. Antibodies to specific infectious agents may shed light into the mechanisms of induction of SLE. The aim of this study was to investigate the prevalence of seropositivity and the titers of antibodies to bacterial, viral, and parasitic agents in SLE patients compared with non-autoimmune controls. Sera from 260 individuals (120 SLE patients and 140 controls) were tested by the BioPlex 2200 Multiplexed Immunoassay method (BioRad) for the prevalence and titers of antibodies to eight infectious agents (Epstein-Barr virus: early antigen IgG, nuclear antigen IgG, viral capsid antigen IgG and IgM, heterophile IgM; cytomegalovirus IgG and IgM; Toxoplasma gondii IgG and IgM; rubella IgG and IgM; Treponema pallidum TPr15G, TPr17G, TPr47G; herpes simplex virus type 1 and 2 IgG; hepatitis C virus and hepatitis B core antibodies. Cytomegalovirus IgM and Epstein-Barr virus early antigen IgG (but not other Epstein-Barr virus antigens) were significantly more prevalent in SLE patients than in controls. Conversely, positive titers of hepatitis B core and rubella IgG antibodies were less prevalent in the SLE patients than in controls. Other differences in titer positivity prevalence were not detected between patients and controls. The titers of the cytomegalovirus IgM, Toxoplasma IgG, Epstein-Barr virus early antigen, and viral capsid antigen IgG antibodies were significantly higher in SLE compared with controls. Our data suggest the importance of previous exposure to infectious agents in the induction and the prevention of SLE.

Cross-talk of the environment with the host genome and the immune system through endogenous retroviruses in systemic lupus erythematosus

Environmental factors are capable of triggering the expression of human endogenous retroviruses and induce an autoimmune response. Infection can promote the expression of human endogenous retroviruses by molecular mimicry or by functional mimicry. There are additional mechanisms which may control the expression of human endogenous retroviruses, such as epigenetic status of the genome (hypomethylation, histone deacetylation). Ultraviolet exposure, chemicals/drugs, injury/stress, hormones, all as a single cause or in a concert, may modulate the involvement of human endogenous retroviruses in pathogenic processes. In the current review we summarize the current knowledge on infections, molecular mimicry, cross-reactivity and epigenetics contribution for trigger human endogenous retroviruses expression and pathogenesis in lupus patients. Lupus (2009) 18, 1136—1143.

Adjuvants and autoimmunity

Some adjuvants may exert adverse effects upon injection or, on the other hand, may not trigger a full immunological reaction. The mechanisms underlying adjuvant adverse effects are under renewed scrutiny because of the enormous implications for vaccine development. In the search for new and safer adjuvants, several new adjuvants were developed by pharmaceutical companies utilizing new immunological and chemical innovations. The ability of the immune system to recognize molecules that are broadly shared by pathogens is, in part, due to the presence of special immune receptors called toll-like receptors (TLRs) that are expressed on leukocyte membranes. The very fact that TLR activation leads to adaptive immune responses to foreign entities explains why so many adjuvants used today in vaccinations are developed to mimic TLR ligands. Alongside their supportive role, adjuvants were found to inflict by themselves an illness of autoimmune nature, defined as ‘the adjuvant diseases’. The debatable question of silicone as an adjuvant and connective tissue diseases, as well as the Gulf War syndrome and macrophagic myofaciitis which followed multiple injections of aluminium-based vaccines, are presented here. Owing to the adverse effects exerted by adjuvants, there is no doubt that safer adjuvants need to be developed and incorporated into future vaccines. Other needs in light of new vaccine technologies are adjuvants suitable for use with mucosally delivered vaccines, DNA vaccines, cancer and autoimmunity vaccines. In particular, there is demand for safe and non-toxic adjuvants able to stimulate cellular (Th1) immunity. More adjuvants were approved to date besides alum for human vaccines, including MF59 in some viral vaccines, MPL, AS04, AS01B and AS02A against viral and parasitic infections, virosomes for HBV, HPV and HAV, and cholera toxin for cholera. Perhaps future adjuvants occupying other putative receptors will be employed to bypass the TLR signaling pathway completely in order to circumvent common side effects of adjuvant-activated TLRs such as local inflammation and the general malaise felt because of the costly whole-body immune response to antigen. Lupus (2009) 18, 1217—1225.

Common infectious agents prevalence in antiphospholipid syndrome

Antiphospholipid syndrome is characterized by thrombosis and pregnancy loss. Infections are generally associated with autoimmune diseases, but in the setting of antiphospholipid syndrome this link has been suggested as having a pathogenic role. In this study, 98 patients with antiphospholipid syndrome were screened for antibodies directed to several infectious agents. The main finding in this study is the significantly higher prevalence of IgM antibodies to toxoplasma and rubella. This novel finding suggests that these infections might be associated with antiphospholipid syndrome. As autoimmune diseases and, in particular, antiphospholipid syndrome are associated with infections, mainly the catastrophic type of the syndrome, this finding implies that a current infection with these agents, i.e. toxoplasma and rubella, might either be related to the pathogenesis of antiphospholipid syndrome or alternatively to its manifestations. Lupus (2009) 18, 1149—1153.

Serum inflammatory cytokines, complement components, and soluble interleukin 2 receptor in primary biliary cirrhosis

Primary biliary cirrhosis (PBC) is a chronic cholestatic autoimmune liver disease characterized by selective destruction of the intrahepatic bile ducts and highly specific serum anti-mitochondrial autoantibodies (AMA). Several studies have attempted to determine the cytokine pattern characterizing PBC, yet no definitive data have been gathered. The present study was designed to evaluate pro-inflammatory cytokines (IL-1beta, IL-6, TNFalpha), soluble IL-2 receptor (sIL-2R, e.g. soluble CD25), and complement components (C1q, C3, factor B, properdin) levels in sera from 84 patients with PBC and 41 controls. PBC was characterized by significantly higher levels of all pro-inflammatory cytokines when compared to controls; these included IL-1beta (433.3 +/- 13.2 vs. 316.6 +/- 14.7 pg/ml, P < 0.001), IL-6 (701 +/- 17.4 vs. 158 +/- 22.5 pg/ml, P < 0.001), TNFalpha (3.38 +/- 0.6 pg/ml vs. undetectable, P = 0.001), and sIL-2R (1527.1 +/- 106 vs. 566.4 +/- 28.7 U/ml, P < 0.001). Similarly, all complement components were also significantly higher in PBC compared to control sera. In conclusion, PBC sera manifest higher levels of sIL-2R and complement components and this may reflect a perpetuated immune activation. As expected, we also report that all major pro-inflammatory cytokine levels are enhanced in PBC. Further longitudinal analyses could demonstrate a correlation between these markers and disease stage or inflammatory activity, to predict histological staging, disease activity, and response to treatment.

Intravenous immunoglobulins in systemic lupus erythematosus: from the bench to the bedside

This article is an update on the clinical and research data available on systemic lupus erythematosus (SLE) and intravenous immunoglobulin (IVIg) therapy that includes some studies performed under the umbrella of the European Working Party on SLE. Various mechanisms of IVIg may play a role, some synergistically, in the modulation of SLE. Recently it has been suggested that IVIg also suppresses the expansion of autoreactive B lymphocytes through signalling of the FcgRIIB, idiotype-mediated inhibition of B cell receptors and neutralisation of cytokines such as the B cell survival factors (B cell activation factor (BAFF and APRIL). In case reports and in open trials, high-dose IVIg (2 g/kg over a 5-day period) has consistently been shown to be a beneficial and safe adjunct therapeutic agent for over 20 manifestations in patients with SLE. It can be given as a first choice of therapy in some cases, for example, in neurological involvement and in those patients who refuse certain immunosuppressive agents such as cyclophosphamide, or in patients who have concomitant infections. Furthermore, IVIg may have a steroid-sparing effect although this characteristic needs further investigation. Specific IVIg (an anti-idiotype to anti-DNA, phosphorylcholine and antiphospholipids) has been shown to be effective in experimental murine models. Hence, extractable IVIg that is directed to the specific pathogenic immunoglobulins will enable the more specific therapy for patients with lupus.

Novel biomarkers of acute kidney toxicity

Novel biomarkers of kidney toxicity are powerful tools not only with respect to their clinical applications but also because of their impact on drug development. These biomarkers can influence the assessment of efficacy of new drugs for kidney diseases as well as the risk management for new drugs. The science behind these novel biomarkers reflects the evolution over the past decade of genomic and proteomic platforms that have transformed the discovery and development of new biomarkers for preclinical and clinical applications in drug development. Several of these biomarkers are in use as transcriptomic biomarkers in animal models as well as translational proteomic biomarkers in animal models and in humans. Their ability to detect kidney damage earlier than is possible with currently accessible biomarkers is being given qualification through regulatory biomarker-qualification programs, which will help establish consensus for their widespread use.