Monocytes from Sjögren's syndrome patients display increased vasoactive intestinal peptide receptor 2 expression and impaired apoptotic cell phagocytosis

Sjögren's syndrome (SS) is a chronic autoimmune disease characterized by salivary and lacrimal gland dysfunction. Clinical observations and results from animal models of SS support the role of aberrant epithelial cell apoptosis and immune homeostasis loss in the glands as triggering factors for the autoimmune response. Vasoactive intestinal peptide (VIP) promotes potent anti-inflammatory effects in several inflammatory and autoimmune disease models, including the non-obese diabetic (NOD) mouse model of SS. With the knowledge that VIP modulates monocyte function through vasoactive intestinal peptide receptors (VPAC) and that immune homeostasis maintenance depends strongly upon a rapid and immunosuppressant apoptotic cell clearance by monocytes/macrophages, in this study we explored VPAC expression on monocytes from primary SS (pSS) patients and the ability of VIP to modulate apoptotic cell phagocytic function and cytokine profile. Monocytes isolated from individual pSS patients showed an increased expression of VPAC2 subtype of VIP receptors, absent in monocytes from control subjects, with no changes in VPAC1 expression. VPAC2 receptor expression could be induced further with lipopolysaccharide (LPS) in pSS monocytes and VIP inhibited the effect. Moreover, monocytes from pSS patients showed an impaired phagocytosis of apoptotic epithelial cells, as evidenced by reduced engulfment ability and the failure to promote an immunosuppressant cytokine profile. However, VIP neither modulated monocyte/macrophage phagocytic function nor did it reverse their inflammatory profile. We conclude that monocytes from pSS patients express high levels of VPAC2 and display a deficient clearance of apoptotic cells that is not modulated by VIP.

[Acute bilateral sensorineural hearing loss caused by immuno-mediated inner ear disease]

The audiovestibular system can be affected by an immunologic etiology. The immune-mediated inner ear disease (IMIED) is a syndrome that includes rapidly progressive sensorineural hearing loss, vertigo and tinnitus, which occurs as a primary disorder or complicates certain autoimmune systemic conditions. However, if treated promptly with immunosuppression, the audiological sequel of IMIED may be avoided. We present a 28 year old female patient, who after rhinitis and mioarthralgias developed a vestibular syndrome. A week later she experienced bilateral hearing loss that progressed to deafness in 72 hours. The examination revealed horizontal and torsional nystagmus, a disrupted vestibulo-ocular reflex and vertigo with the positional changes. Laboratory data were normal except for eritrosedimentation rate (75 mm/1 hour). The autoantibodies usually present in rheumatologic autoimmune systemic diseases were negative. The antibodies to the 68-kD antigen found in the inner ear were positive. The chest x-ray and sinus x-ray were normal. The head magnetic resonance imaging with gadolinium and ear computed tomography were normal. Cerebrospinal fluid studies showed normal findings. With the possible diagnosis of IMIED we started early treatment with corticosteroids, with improvement in auditory and vestibular function thereafter. We highlight the early recognition of IMIED as a differential diagnosis in patients with acute bilateral hearing loss, because prompt treatment with immunosuppression might have a positive effect on auditory function recovery.

Activation of nitric oxide signaling through muscarinic receptors in submandibular glands by primary Sjögren syndrome antibodies

Primary Sjögren Syndrome is a chronic autoimmune disease characterized by exocrine gland dysfunction. Here we present evidence of the activation of nitric oxide signaling cascade by circulating antibodies of patients with Sjögren Syndrome in rat submandibular glands. Constitutive nitric oxide synthase and cyclic GMP levels are modulated by Sjögren IgGs through the activation of muscarinic acetylcholine receptors on the glands. The effects are similar to those produced by the agonist carbachol and blocked by the antagonist atropine. The involvement of M1 subtype of muscarinic receptors is proposed since both a synthetic peptide homologous to an extracellular domain of M1 receptor and pirenzepine, a selective M1 antagonist, partially blocked the effects. We conclude that Sjögren Syndrome antibodies can activate nitric oxide signaling in submandibular glands by interacting with muscarinic acetylcholine receptors.

Prevalence of autoantibodies to ribosomal P proteins in juvenile-onset systemic lupus erythematosus compared with the adult disease

OBJECTIVE

To determine the prevalence of anti-ribosomal P (anti-P) proteins in several groups of patients with juvenile-onset systemic lupus erythematosus (SLE) in comparison with the prevalence in adult SLE.

METHODS

Serum samples were pooled together from 3 cohorts of patients with juvenile-onset SLE in 3 different medical centers and from a miscellaneous group of juvenile-onset SLE patients whose samples were sent by regional physicians. Sera were studied for the presence of anti-P using 2 assays: Western blot with ribosomes as antigen, and an enzyme-linked immunosorbent assay with the COOH-terminal 22 amino acids of the ribosomal P protein in a multiantigenic peptide format as antigen. Sera found positive by both tests were considered positive for anti-P antibodies. Findings from similar studies involving a large cohort of patients with adult-onset SLE from Oklahoma City were used for comparison.

RESULTS

The prevalence of anti-P antibodies in the pooled sample of juvenile-onset SLE sera was 45 of 108, or 42%, while in the adult cohort from Oklahoma City, 20 of 260, or 7.7%, were positive for anti-P (odds ratio [OR] 9.6, P < 10(-8) by Fisher's exact test). In addition, it was shown that 12 of 13 patients with both anti-P and anti-double-stranded DNA (anti-dsDNA) in the juvenile SLE cohort had nephritis, while only 8 of 22 patients without both antibodies were nephritic (OR 21.0, P < 10(-8)). It was also shown that in 9 illustrative cases, the levels of anti-P and anti-dsDNA antibodies usually varied together and in concordance with the clinical activity as measured by the SLE Disease Activity Index (SLEDAI). Finally, anti-P-positive and anti-P-negative patients had a similar prevalence of anti-dsDNA, anti-Ro/SSA, and anti-La/SSB antibodies, but patients with anti-P had a higher prevalence of anti-U1 RNP and anti-Sm (P = 0.041 and P = 0.0385, respectively, by Fisher's exact test).

CONCLUSION

Antibodies to ribosomal P protein are more prevalent in juvenile-onset SLE than in adult-onset SLE. Levels of antibodies to ribosomal P protein vary with the clinical disease activity as measured by the SLEDAI, often in concordance with the levels of anti-dsDNA. The presence of both anti-P and anti-dsDNA antibodies was powerfully associated with nephritis in the cohort of patients for whom comprehensive clinical and serologic data were available.

Autoantibodies against lacrimal gland M3 muscarinic acetylcholine receptors in patients with primary Sjögren's syndrome

PURPOSE

The authors demonstrated that immunoglobulin G, present in the sera of patients with primary Sjögren syndrome (pSS), could recognize and activate muscarinic acetylcholine receptors (mAChRs) of rat exorbital acrimal gland.

METHODS

Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), immunoblotting, and radioligand binding and biologic assays were used to demonstrate autoantibodies against mAChRs.

RESULTS

These autoantibodies recognized by means of SDS-PAGE and immunoblotting assay a band of approximately 70 kDa expressed on lacrimal gland membranes that comigrated with the peak of labeled mAChRs. Moreover, pSS IgG were able to inhibit, in an irreversible manner, the binding of [3H]quinuclidinyl benzilate to mAChRs of rat exorbital lacrimal glands and to simulate the biologic effect of mAChR agonists, because they trigger the activation of phosphoinositide turnover. Atropine and 4-diphenylacetoxy-N-methylpiperidine methiodide blocked the effect and carbachol mimicked it, confirming that the M3 subtype mAChRs mediated pSS IgG action. As control, IgG from sera of women without pSS gave negative results on immunoblotting, binding, and biologic assays, thus demonstrating the specificity of the reaction.

CONCLUSIONS

Autoantibodies against mAChRs may be considered among the serum factors implicated in the pathophysiology of the development of pSS dry eyes.

Congenital heart block and subsequent connective tissue disorder in adolescence

A young girl born to a mother with systemic lupus erythematosus (SLE) had congenital heart block and developed symptoms of a connective tissue disorder at the age of 13 y. When first seen at the age of 15 y she was found to have an unclassified connective tissue disorder and to be seropositive for anti Ro/SSA and U1 RNP. This constellation of clinical/serological features has not been described among the reported handful of patients with congenital heart block and subsequent development of a connective tissue disorder.

Interleukin 6: a possible marker of disease activity in adult onset Still's disease

OBJECTIVE

Adult onset Still's disease (AOSD) is an inflammatory disorder with elevated serum acute phase proteins. Interleukin-6 is a major contributor to the acute phase response. We therefore examined the serum levels of CRP, SAA and interleukin-6 in active and inactive AOSD.

RESULTS

Active patients had significantly elevated CRP, SAA, and interleukin-6 values. After steroid treatment a marked reduction was observed in all three parameters. There was a close kinetics on the fluctuations of CRP and SAA, but not on IL-6.

CONCLUSION

Acute phase proteins and IL-6 are useful markers of disease activity in AOSD.

Circulating antibodies against neonatal cardiac muscarinic acetylcholine receptor in patients with Sjögren's syndrome

Isolated congenital heart block may be associated with Primary Sjögren's Syndrome. In this work we demonstrated that IgG present in the sera of patients with Primary Sjögren's Syndrome (PSS) could bind and activate muscarinic acetylcholine receptors of rat neonatal atria. These antibodies were able to inhibit in a irreversible manner the binding of 3H-QNB to muscarinic cholinergic receptors of purified rat atria membranes. Moreover, IgG from PSS individuals could modify biological effects mediated by muscarinic cholinoceptors activation, i.e. decrease contractility and cAMP and increase phosphoinositide turnover and cGMP. Atropine blocked all of these effects and carbachol mimicked them; confirming muscarinic cholinergic receptors-mediated PSS IgG action. Neither binding nor biological effect were obtained using adult instead of neonatal rat atria. IgG from sera of normal women were not effective in the studied system. The prevalence of cholinergic antibody was 100% in PSS and was independent of Ro/SS-A and La/SS-B antibodies. It could be concluded that antibody against muscarinic cholinergic receptors may be another serum factor to be considered in the pathophysiology of the development of congenital heart block.

Circulating antibodies against rat parotid gland M3 muscarinic receptors in primary Sjögren's syndrome

In this study we demonstrate that IgG present in the sera of patients with primary Sjögren's syndrome (PSS) could bind and activate muscarinic acetylcholine receptors (mAChRs) of rat parotid gland. These antibodies were able to inhibit in a non-competitive manner the binding of 3H-quinuclidinyl benzilate (QNB) to mAChRs of purified rat parotid gland membranes. Moreover, IgG from PSS could modify biological effects mediated by mAChR activation; i.e. decrease cAMP, increase phosphoinositide turnover without affecting cGMP. Atropine and 4-DAMP blocked all of these effects, and carbachol mimicked them, confirming the M3 subtype mAChRs mediated PSS IgG action. Neither binding nor biological effect were obtained with IgG from sera of normal women. The prevalence of cholinergic antibody was 100% in PSS, and was independent of Ro/SS-A and La/SS-B antibodies. It could be concluded that antibody against mAChRs may be another serum factor to be considered in the pathophysiology of the development of PSS.

Clinical and serological identification of 2 forms of complete heart block in children

OBJECTIVE

To study the association of maternal antibodies to Ro(SSA) and/or La(SSB) with isolated complete congenital heart block (CCHB) in children according to the child's age at detection.

METHODS

Sera from 17 mothers of 18 children with CCHB of unidentified cause were studied. Autoantibodies were measured by double immunodiffusion, enzyme linked immunosorbent assay (ELISA), Western blot, and immunoprecipitation from cell extracts. Statistical analysis used the chi 2 test with Yates' correction.

RESULTS

CCHB was diagnosed in 12 children of 11 mothers before the age of 3 mo (Group A) and in 6 children of 6 mothers after the age of 17 mo (Group B). Seven Group A mothers and no Group B mother had connective tissue disorders; autoantibodies were found in 9/11 Group A and in 1/6 Group B mothers (p < 0.01). Eight Group A children needed a pacemaker and one other died of cardiac insufficiency, whereas only one of the 6 Group B children needed a pacemaker. Interestingly, this latter child was the only one from Group B whose mother's serum contained autoantibodies. Irrespective of their age at diagnosis, the children with CCHB who needed a pacemaker and the one who died were born to mothers with autoantibodies (p < 0.001).

CONCLUSION

CCHB detected before the age of 3 mo is highly associated with the presence of anti-Ro(SSA)/La(SSB) in the mothers, while CCHB diagnosed later is generally not. For epidemiological studies, the former type should be considered early onset as opposed to late onset CCHB in the latter type. Establishing this clinicoserological distinction is also important for the children, since it alerts the clinician to a more severe prognosis (necessity of a pacemaker), even in the rare occurrence of late diagnosed CCHB.

Circulating antibodies against neurotransmitter receptor activities in children with congenital heart block and their mothers

In this work we demonstrated that IgG present in the sera of patients with congenital heart block (CHB) and their mothers could bind and activate beta adrenoceptors and muscarinic cholinergic receptors of neonatal heart. These antibodies were able to inhibit in a noncompetitive manner the binding of [3H]QNB and [3H]CGP to muscarinic cholinergic and beta adrenoceptors of purified neonatal rat myocardial membranes, respectively. Moreover, IgG from children with CHB and their mothers could modify biological effects mediated by these neurotransmitter receptors, i.e., heart contractility and cAMP production. Neither binding nor biological effects were obtained using adult instead of neonatal rat atria. Both reactivities (adrenergic and cholinergic) were independent of Ro/SS-A and La/SS-B antibodies and were absent in the sera of normal women of childbearing age and of normal children. It could be concluded that antibodies against cardiac neurotransmitter receptors may be another serum factor (or factors) to be considered in the pathophysiology of the development of CHB.

Guidelines for use of antirheumatic drugs

The Vth WHO/ILAR Task Force Meeting on Rhemuatic Diseases ratified guidelines for the use of antirheumatic drugs. Indications for use, contraindications, dose, administration and other usage principles, toxicity, and advice to patients have been agreed for analgesics, nonsteroidal antiinflammatory drugs, slower acting antirheumatic drugs, corticosteroids, and hypouricemic agents.

Antibodies against beta adrenoceptors in mothers of children with congenital heart block

To determine whether antibodies against beta adrenergic activity interact with neonatal cardiac cell receptors and alter their physiological behaviour. An "in vitro" experimental model measuring the frequency of contraction, the production of cAMP and binding assay on neonatal and adult rat atria was employed. Sera and IgG fraction from mothers of infants with congenital heart block (CHB) interact with neonatal rat atria increasing the frequency of contraction and cAMP production. These effects were abolished by propranolol, pointing to a beta adrenergic participation. IgG also competed with 3H-CGP to beta adrenergic receptors on neonatal cardiac membranes. Neither the contractile nor the cAMP effects or binding assay were obtained using adult instead of neonatal rat atria. Reactivity against cardiac neurotransmitter receptors may be another serum factor(s) to be considered in the pathophysiology of the development of CHB.

Fatal post-partum pulmonary vasculitis in systemic lupus erythematosus

A patient with fatal acute pulmonary vasculitis complicating systemic lupus erythematosus (SLE) of ten years duration is described. The patient died seven days after an uneventful pregnancy and delivery. Pathologic examination demonstrated acute necrotizing changes as well as organized lesions in pulmonary arteries. Acute pulmonary arteritis is rare in SLE and may develop as one of the major complications of the disease in the potentially dangerous post-partum period.

Serum amyloid protein levels in south american children with rheumatoid arthritis: a co-operative study

Serum amyloid protein (SAA) levels were determined by radioimmunoassay in 90 children with juvenile rheumatoid arthritis (JRA). Significantly higher levels of SAA were present in children with the polyarticular and systemic forms of the disease. SAA levels correlate with disease activity, increasing during acute exacerbations, decreasing during remission and in patients having prednisone therapy. High serum SAA concentrations in children with JRA did not correlate with the presence of secondary amyloidosis and may be useful as a disease monitor.