[Infections and vasculitis]

Vasculitides are rare diseases characterized by inflammation of blood vessels. According to diameter of the blood vessels involved in the inflammatory process, the clinical presentation and the histological appearance, different vasculitic syndromes may be distinguished. Primary vasculitides are of unknown origin while secondary vasculitides may be caused by drugs, malignancy or infection. Panarteriitis nodosa caused by chronic Hepatitis B and mixed cryoglobulinemia secondary to chronic Hepatitis C are classical examples of vasculitides triggered by infections. However, these are rare complications of chronic viral hepatitis. Patients infected by HIV frequently suffer from vasculitis, which may be caused by opportunistic infections and by defects in immune regulation. In numerous case reports, various other infectious particles have been reported to cause different forms of vasculitis, either by direct infection of endothelial cells or by induction of an immunologic process leading to blood vessel destruction. Immunologically mediated vasculitis secondary to infection may be due to a predisposing reactivity of the patient's immune system. After successful treatment of the infection, the vasculitis usually subsides. Therefore, all patients with vasculitis should be evaluated for underlying infection.

Estimation of the cut-off value in cardiovascular autonomic nervous function tests: not-age-related criteria or the age-related 5th percentile

The aim of the study was to estimate the cut-off value of cardiovascular tests using not-age-related criteria or the age-related 5th percentile in 165 diabetic patients. The cANP, pANP, and smNP were assessed using previously recommended standardized test procedures. Prevalence of overall definite (borderline) cANP was 35.2% (23.0%) when using the 5th percentile or 16.4% (27.9%) when using not age-related criteria (p for the difference < 0.0001) (p = 0.3205). Prevalence of pANP was 54.0% and of smNP 37.0%. Concerning cANP, the number of test results below the 5th percentile (N5) correlated significantly with the number of abnormal test results using not age-related criteria (Nnar) (p < 0.000001) but the slope of the regression line differed substantially from 1. Using the 5th percentile as the cut-off value for cANP testing, sensitivity and specificity were calculated for not age-related criteria for respiratory sinus arrhythmia (90.5%, 80.2%), Valsalva test (30.4%, 98.0%), lying-to-standing test (46.3%, 98.7%), orthostatic systolic blood pressure fall (69.0%, 78.3%), and overall definite cANP (44.8%, 92.8%). The statistical analysis revealed that the age-related 5th percentile is superior to the not-age-related cut-off values in diabetic patients. We therefore suggest that age-related normal values (percentiles) have to be applied when cANP is estimated.

High prolactin and low dehydroepiandrosterone sulphate serum levels in patients with severe systemic sclerosis

The aim was to determine serum levels of prolactin (PRL) and dehydroepiandrosterone sulphate (DHEAS), and to demonstrate a link between PRL or DHEAS and soluble immune mediators in patients with systemic sclerosis (SSc) with different degrees of disease-induced organ involvement. Thirty-one patients with SSc were studied to evaluate 18 possible disease manifestations. In the serum, PRL, DHEAS and soluble immune mediators were determined by ELISA. Compared to SSc with <9 disease manifestations, patients with > or =9 disease manifestations had higher PRL (P = 0.044), higher soluble interleukin 2 receptor (sIL-2R, P = 0.004) and vascular cell adhesion molecule (sVCAM, P = 0.044), and lower DHEAS (P = 0.029). PRL (R(Rank) = 0.490, P = 0.003) and DHEAS (R(Rank) = -0.399, P = 0.013) were significantly correlated with the number of disease manifestations. The inverse correlation between PRL and DHEAS showed a trend (P = 0.059). PRL correlated with sIL-2R (R(Rank) = 0.553, P = 0.001) and sVCAM (R(Rank) = 0.520, P = 0.002). The number of disease manifestations and sIL-2R correlated significantly (R(Rank) = 0.463, P = 0.006). Psychometric variables to examine the presence of depression were not measured, but from the general aspect, the patients were not suffering from major depression which may have influenced our results. In conclusion, this study demonstrates the close association between DHEAS and, particularly, PRL and SSc severity and T-lymphocyte mechanisms.

Neuronal regulation of interleukin 6 secretion in murine spleen: adrenergic and opioidergic control

The PNS was anticipated to be involved in the modulation of immune responses. To study aspects of this neuronal-immune communication, a recently developed tissue slice method was used to study the effects of adrenergic and opioidergic transmitters on interleukin 6 (IL-6) secretion in the spleen. The alpha 2-adrenergic agonist p-aminoclonidine (10(-7) M) inhibited IL-6 secretion (control vs. p-aminoclonidine, 100.0 +/- 4.76 vs. 59.3 +/- 6.6% of control values; p < 0.001). The alpha 1-adrenergic agonist methoxamine (10(-8) M) also inhibited IL-6 secretion (100.0 +/- 4.8 vs. 71.5 +/- 3.8%; p < 0.001). The endogenous opioids beta-endorphin (10(-10) M), methionine-enkephalin (10(-9) M), and leucine-enkephalin (10(-9) M) inhibited IL-6 secretion as well (p = 0.0051, p = 0.0337, and p = 0.0226, respectively). Electrical stimulation of spleen slices inhibited IL-6 secretion (100.0 +/- 4.3 vs. 56.7 +/- 4.6% of control values; p < 0.001). The involvement of alpha-adrenergic and opioidergic molecules in this electrically induced inhibition was shown by the use of antagonists. Electrical inhibition of IL-6 secretion was attenuated by phentolamine (10(-7) M; p = 0.0345), by naloxone (10(-6) M; p = 0.0046), by cyprodime (10(-8) M; p = 0.0014), and by the combination of cyprodime (10(-7) M) plus phentolamine (10(-8) M; p < 0.0001). We conclude from the complementary studies that the inhibition of IL-6 secretion induced by electrical pulses was mostly mediated by alpha-adrenergic and mu-opioidergic endogenous transmitters.

Incidence of serum anti-P/O-type and anti-N-type calcium channel autoantibodies in the Lambert-Eaton myasthenic syndrome

The Lambert-Eaton myasthenic syndrome (LEMS) is an autoimmune disease in which autoantibodies are directed against voltage-gated calcium channels (VGCCs) at presynaptic nerve terminals. We first demonstrated the presence of P/Q-type and N-type VGCCs in digitonin extracts prepared from human and rabbit cerebellum using the specific ligands 125I-omega-conotoxin MVIIC (125I-omega-CmTx) and 125I-omega-conotoxin GVIA (125I-omega-CgTx), respectively. We then tested sera from 72 LEMS patients' 25 with proven small cell lung cancer (SCLC) and 66 healthy or other neurological, SCLC or autoimmune disease controls in an immunoprecipitation assay using 125I-omega-CmTx-labelled (P/Q-type) VGCCs in human cerebellar extract. Sixty-six of 72 LEMS serum samples (91.7%) were positive for the presence of VGCC antibodies, as defined as a titre greater than 3 standard deviations above the mean for the healthy controls (n = 22). Rabbit cerebellar extract as antigen gave similar results (r = 0.94, P < 0.001, n = 30). By contrast, only 24/72 (33%) LEMS sera were positive in the assay for anti-N-type VGCC antibodies using 125I-omega-CgTx. All these 24 were also positive in the 125I-omega-CmTx assay. All healthy and disease control sera were negative in both assays. The anti-P/Q-type VGCC antibody titres did not correlate with an electrophysiological index of disease severity across individuals; however, longitudinal studies in a LEMS patient with SCLC receiving chemotherapy, and in a non-SCLC LEMS patient receiving immunosuppressive therapy showed an inverse relation between antibody titre and disease severity. These results support the view that anti-P/Q-type VGCC antibodies are implicated in the motor disorder in LEMS, and show that the omega-CmTx radioimmunoassay is a highly specific and sensitive means of detecting them.

Relapsing polychondritis: clinical and immunogenetic analysis of 62 patients

OBJECTIVE

In this study we describe clinical and immunogenetic findings in 62 unselected patients with relapsing polychondritis.

METHODS

In a multicenter study, clinical data of 26 (41.9%) female and 36 (58.1%) male patients were collected. HLA-DR specificities were identified in 60, and the frequencies were compared with those in healthy controls.

RESULTS

The median age at the time of diagnosis was 46.6 years (range 17 to 86). 58 (93.5%) patients had auricular chondritis, 31 (50.0%) ocular symptoms, 35 (56.5%) nasal involvement. Involvement of joints (53.2%), respiratory system (30.6%), skin (24.2%), cardiovascular system (22.6%), central nervous system (9.7%), and kidneys (6.5%) was found as well. 22 (35.5%) patients had associated diseases such as systemic lupus erythematosus or rheumatoid arthritis. Susceptibility to relapsing polychondritis was significantly associated with HLA-DR4 (p < 0.001). There was no difference in the frequency or distribution of DRB1*04 subtype alleles between patients and healthy controls. The extent of organ involvement was negatively associated with HLA-DR6 (p < 0.011).

CONCLUSION

Immunogenetic findings as well as similarities and overlapping clinical symptoms with other autoimmune or rheumatic diseases suggest that immunological mechanisms play a major role in the pathogenesis of relapsing polychondritis.

Esophageal manometry in systemic sclerosis: screening procedure or confined to symptomatic patients?

The predictive value of esophagus-related symptoms for the diagnosis of esophageal dysmotility induced by systemic sclerosis (SSc) was prospectively evaluated in 50 consecutive patients with SSc. Patients were classified as symptomatic when either dysphagia or repeated episodes of heartburn were present. All patients underwent esophageal manometry; SSc-induced esophageal dysfunction was diagnosed when there was aperistalsis or marked hypocontractility of the distal two-thirds of the esophageal body. Twenty-nine patients (58%) had a history of esophagus-related symptoms, while 21 patients (42%) were asymptomatic. Compared to esophageal manometry, esophagus-related symptoms had a sensitivity of 64%, a specificity of 52%, a negative predictive value of 50% and a positive predictive value of 62% for the diagnosis of SSc-induced esophageal dysfunction. In conclusion, the association of esophagus-related symptoms and esophageal motility pattern is poor. As clinical management strategies depend on proof of esophageal dysfunction, screening examinations are mandatory in all patients with SSc.

Identification of phospholipase A2 and neurotoxic activities in the venom of the New Guinean small-eyed snake (Micropechis ikaheka)

The Papua New Guinean small-eyed snake (Micropechis ikaheka) is recognised as a cause of life-threatening envenoming in certain parts of New Guinea. The clinical features suggest the presence of toxins acting at the neuromuscular junction and on muscle. We have used the mouse phrenic nerve hemidiaphragm preparation, a phospholipase A2 assay, and 125I-neurotoxin-binding radioimmunoassays to look for toxic activities in the crude venom and in preliminary high-performance liquid chromatography (HPLC) fractions. Micropechis ikaheka venom at 1 and 3 micrograms/ml completely abolished nerve-evoked muscle twitch within 70 min at 37 degrees C. There was also a sustained contracture of the muscle and some reduction in twitch tension evoked by direct stimulation; these were explained by the presence of phospholipase A2 activity. The venom inhibited the binding of 125I-alpha-bungaro-toxin to detergent-extracted human muscle acetylcholine receptor (AChR), and inhibited acetylcholine receptor function in a muscle cell line. It also inhibited binding of 125I-omega-conotoxin GVIA to detergent-extracted human frontal cortex voltage-gated calcium channels, but this appeared to be dependent on the phospholipase A2 activity. Identification of the main neurotoxic fractions following HPLC are shown.

Autoantibodies against the protease inhibitor calpastatin: a new risk factor for venous thrombosis?

Autoantibodies reactive against human calpastatin were detected by screening a cDNA expression library with the serum of a 53 year old white female patient with a history of venous thrombosis and suspected antiphospholipid syndrome. When further sera were analyzed it could be shown that > 90% of calpastatin autoantibodies, detected by Western blotting against the partial calpastatin clone, react with the C-terminal amino acids of the protein. Therefore, an ELISA based on a synthetic peptide containing the C-terminal 27 amino acids of calpastatin was developed and 205 healthy blood donors and 138 random sera from hospital patients were analyzed. A total of 11 sera (3.2%) were positive with no significant difference between the two groups (7/205 and 4/138). In 80 consecutive patients with a history of venous thrombosis 9 positive sera (11.3%; p < 0.01 vs. blood donors, p < 0.02 vs. hospital patients) were detected. Our results indicate that autoantibodies against calpastatin may constitute a so far unknown risk factor for venous thrombosis.

Autoimmunity to ion-channels and other proteins in paraneoplastic disorders

Paraneoplastic neurological disorders are rare conditions caused by immune responses against tumour antigens that cross-react with neuronal antigens. In the past year, there have been advances in the definition of some of the antigens that are recognized by patients' antibodies, and new observations on the results of passive and active immunization against the antigens.

Neuroimmune control of interleukin-6 secretion in the murine spleen. Differential beta-adrenergic effects of electrically released endogenous norepinephrine under various endotoxin conditions

In a previous study we demonstrated a superfusion technique which allows for investigation of nerve-immune cell interaction in murine spleen. We demonstrated that under septic-like conditions in the presence of bacteria and lipopolysaccharide (LPS), electrically induced inhibition of interleukin 6 (IL-6) secretion was attenuated by the beta-adrenergic antagonist propranolol. This effect was now investigated more closely under various endotoxin conditions in order to dissect effects of bacteria and endotoxin: (A) bacteria-rich conditions (without penicillin/streptomycin [P/S] and without LPS), (B) LPS-enriched conditions (with P/S and with LPS), and (C) bacteria-free conditions (with P/S and without LPS). Under bacteria-rich conditions, norepinephrine (Emax = 10(-6) M, p = 0.012) and isoproterenol (Emax = 10(-6) M, p = 0.048) concentration-dependently inhibited IL-6 secretion from murine spleen slices in contrast to bacteria-free conditions. In a bacteria-free environment the beta-adrenergic antagonist propranolol did not attenuate the electrically induced inhibition of splenic IL-6 secretion. The insertion of bacterial filters in front of the superfusion chambers to avoid direct contact between bacteria and cells increased the electrically-induced inhibition of IL-6 secretion (p = 0.0036). Added LPS did not change the electrically-induced release of norepinephrine from presynaptic nerve terminals in murine spleen. The study demonstrates two different beta-adrenergic effects on IL-6 secretion of murine spleen slices under bacteria-rich or bacteria-free conditions.

Effects of intravenous immunoglobulin on muscle weakness and calcium-channel autoantibodies in the Lambert-Eaton myasthenic syndrome

Intravenous immunoglobulin improves many antibody-mediated autoimmune disorders, but its mode of action is unknown. We investigated its effects on muscle strength and on the serum titer of the calcium-channel autoantibodies that are likely to be pathogenic in the Lambert-Eaton myasthenic syndrome (LEMS). In a randomized, double-blind, placebo-controlled crossover trial, serial indices of limb, respiratory, and bulbar muscle strength and the serum titer of calcium-channel antibodies in nine patients were compared over an 8-week period, using the area-under-the-curve approach, following infusion on two consecutive days of immunoglobulin at 1 g/kg body weight/day (total dose 2.0 g/kg body weight) or placebo (equivalent volume of 0.3% albumin). Calcium-channel antibodies were measured by radioimmunoassay using 125I-omega-conotoxin MVIIC. Direct anti-idiotypic actions of immunoglobulin were tested in this assay. Immunoglobulin infusion was followed by significant improvements in the three strength measures (p = 0.017 to 0.038) associated with a significant decline in serum calcium-channel antibody titers (p = 0.028). Improvement peaked at 2 to 4 weeks and was declining by 8 weeks. Mean serum titers were unchanged at 1 week, however, and direct anti-idiotypic neutralization by immunoglobulin was not demonstrable in vitro. We conclude that immunoglobulin causes a short-term improvement in muscle strength in LEMS that probably results from the induced reduction in calcium-channel autoantibodies. The reduction is not due to a direct neutralizing action of the immunoglobulin, but a delayed anti-idiotypic action cannot be excluded. Improvement following intravenous immunoglobulin in other autoantibody-mediated disorders may similarly be associated with decline in levels of pathogenic autoantibodies.

Atrial natriuretic factor and digoxin-like immunoreactive factor in diabetic patients: their interrelation and the influence of the autonomic nervous system

In diabetic patients, several factors contribute to volume expansion and have to be counteracted by humoral and neuronal feedback control systems. We investigated N-terminal proatrial natriuretic factor (ANF1-98) and digoxin-like immunoreactive factor (DLIF), which are two counteracting hormones, and their interrelationship, with additional consideration given to autonomic nervous function in diabetic patients. ANF1-98 and DLIF were measured in 64 diabetic patients. Autonomic nervous function was assessed using nine autonomic nervous function tests. The patients were subdivided into two groups, one with four or more (group 1) and one with less than four abnormal results in autonomic function tests (group 2). Compared with group 2, group 1 demonstrated detectable DLIF levels less often (17.2 vs. 45.7, P = 0.0195) and increased levels of ANF1-98 (mean +/- SEM: 850.0 +/- 108.8 vs. 554.8 +/- 45.9 pmol/L, P = 0.0099). However, the groups did not differ in blood pressure, daily sodium, and daily potassium excretion. The number of abnormal autonomic function tests correlated significantly with ANF1-98 (P = 0.0002). In patients with detectable DLIF, DLIF correlated with ANF1-98 (P = 0.0080). These results demonstrate close interactions between the autonomic nervous system and the two natriuretic hormones. In patients with autonomic nervous dysfunction, higher levels of ANF may possibly compensate for the lack of the natriuretic DLIF to counteract hypertension and chronic volume expansion.

Gallbladder motility in systemic sclerosis

In 20 patients with systemic sclerosis (SSc) and 24 healthy controls, gallbladder motility was evaluated by abdominal ultrasonography after stimulation by a standard liquid meal. Results from patients with normal and disturbed oesophageal function were analysed separately in order to investigate the significance of gallbladder motility as a parameter for gastrointestinal involvement in SSc. All patients showed a marked decrease in gallbladder size after stimulation (patients 61 +/- 13%; controls 48 +/- 12%). Patients with oesophageal dysfunction (n = 12) had a slightly lower gallbladder contraction (maximal decrease = 58 +/- 13%) when compared to patients with normal oesophageal function (n = 8; 66 +/- 13%); however, this difference was not statistically significant. Gallbladder motility in patients with SSc was not reduced when compared with healthy controls. SSc-induced oesophageal dysfunction was not associated with impaired gallbladder motility. Thus, measurement of gallbladder emptying is not a helpful tool when looking for gastrointestinal involvement in SSc.

Distinct patterns of immunoglobulin classes and IgG subclasses of autoantibodies in patients with inflammatory bowel disease

OBJECTIVE

The pathophysiological significance of autoantibodies in inflammatory bowel diseases (IBD) is still unclear. To assess specific immunological abnormalities we examined the distribution and restriction of immunoglobulin classes and subclasses of anti-neutrophil cytoplasmic antibodies (ANCAs) in ulcerative colitis and of antibodies to pancreatic juice (APJs) in Crohn's disease.

METHODS

We tested 62 sera of patients with ulcerative colitis and 184 sera of patients with Crohn's disease for their immunoglobulin class and IgG subclass distribution of ANCAs (in ulcerative colitis patients) and APJs (in Crohn's disease patients) by fluorescence isothiocyanate (FITC)-labelled anti-human antibodies in an immunofluorescence assay with human granulocytes or pancreas as substrate. Twenty-five patients with Wegener's granulomatosis were used for comparison.

RESULTS

In ulcerative colitis ANCAs were found in 74% of the patients. They were predominantly of the IgG (96%) and IgA class (37%). In Crohn's disease APJs (present in 28% of the cases) were of the IgG (98%) and IgA class (71%). ANCAs in ulcerative colitis were of the IgG1 (73%) and IgG3 (5%) subclasses, APJs in Crohn's disease of the IgG1 (94%), IgG2 (20%) and IgG3 (2%) subclasses. The immunoglobulin class and IgG subclass distributions of ANCAs and APJs resembled the changes in total immunoglobulin classes and IgG subclasses in ulcerative colitis or Crohn's disease.

CONCLUSION

The immunoglobulin classes and IgG subclasses of autoantibodies in ulcerative colitis and Crohn's disease differ from each other and from the distribution of autoantibodies in vasculitic diseases (Wegener's granulomatosis, microscopic vasculitis, systemic lupus erythematosus). These alterations reflect specific pathophysiological features of ulcerative colitis and Crohn's disease.

Dehydroepiandrosterone sulfate is positively correlated with soluble interleukin 2 receptor and soluble intercellular adhesion molecule in systemic lupus erythematosus

OBJECTIVE

To determine whether dehydroepiandrosterone sulfate (DHEAS) is linked with soluble immune mediators in systemic lupus erythematosus (SLE).

METHODS

DHEAS and various soluble immune mediators were measured by ELISA in the serum of 35 patients with SLE (26 women, 9 men) and in 41 control subjects.

RESULTS

DHEAS was lower in patients with SLE compared to controls (male 1.29 +/- 0.32 vs 3.04 +/- 0.33 micrograms/ml, p < 0.001; female 0.75 +/- 0.12 vs 2.16 +/- 0.18 micrograms/ml, p < 0.001). The DHEAS reduction was in part dependent on prior glucocorticosteroid treatment (p < 0.02). After adjustment for multiple comparisons, there was significant negative correlation between steroid dose and DHEAS (RRank = -0.426, p = 0.005), but with none of the soluble immune mediators. No significant difference in the percentage of steroid treated male and female patients was found (p = 0.220). However, there was positive correlation between DHEAS and soluble interleukin 2 receptor in women, but not in men, with SLE [RRank = 0.747 (n = 26, p < 0.0001) vs RRank = -0.1333( n = 9, p = 0.366)] and between DHEAS and soluble intercellular adhesion molecule in women, but not in men, with SLE [RRank = 0.509 (n = 26, p = 0.005) vs RRank = 0.4833 (n = 9, p = 0.094)].

CONCLUSION

These data demonstrate positive interrelation between DHEAS and soluble immune mediators involved in leukocyte function and leukocyte adhesion only in female patients with SLE.

Antigen processing and presentation by a mouse macrophage-like cell line expressing human HLA class II molecules

Macrophages differ from other antigen-presenting cell types in their potential to take up, process and present particulate antigens as well as proteins and peptides. To study their influence on T cell activation we transfected the mouse macrophage-like cell line P388D1 with human genes coding for the alpha and beta chains of class II molecules (DRA*0101 and DRB1*0401 or DRB1*0404) or with a series of localized DR beta mutants. The transfected cells (TP cells) all expressed DR4 molecules on their surface. Since they stimulated some, but not all, human DR4-reactive T cell clones, some of the resident peptides are evidently similar in mouse and man. Proteins and polypeptides such as pepsin or the human acetylcholine receptor (AChR) alpha 37-181 were also processed correctly by these transfectants and then presented efficiently to other T cell clones. Nearly all the mutants tested could present to the pepsin-specific clone, establishing functional expression of the transfected DR molecules. For the more exacting AChR alpha 144-156-specific T cell clone PM-A1, we confirmed that the single Gly86--> Val mutation in the DR beta chain abolished presentation by two DR4 subtypes. If, however, this same replacement was made in a third variant that has Lys71 (rather than Arg71), the effects were less drastic. This approach could also be used to analyse the contributions of individual substitutions that confer susceptibility to rheumatoid arthritis.

Failure of pulse intravenous methylprednisolone treatment in juvenile dermatomyositis

OBJECTIVE

To review the experience with high-dose intravenous pulse methylprednisolone (IVMP) therapy in patients with juvenile dermatomyositis (JDM) in our institution.

STUDY DESIGN

We reviewed the charts of seven consecutive patients (four female subjects; three male subjects; age 3 to 18 years (mean age 8 years) treated for JDM between 1989 and 1992.

RESULTS

All patients met the criteria of Bohan and Peter for JDM and were treated within 3 months of onset of weakness. All received initial treatment with IVMP, 30 mg/kg per day for 3 days, administered weekly for between 1 and 4 weeks. Treatment with orally administered prednisone was required because of deteriorating muscle strength and persistent elevation of creatine kinase activity despite IVMP in five patients, increased skin vasculitis in one patient, and elevated creatine kinase activity with no improvement in strength in one patient.

CONCLUSION

We conclude that muscle strength in patients with JDM may deteriorate during pulse IVMP therapy when this is used alone as initial treatment, even early in the course of the illness. We recommend either conventional high doses of orally administered corticosteroids or IVMP with oral corticosteroid therapy as initial treatment of JDM.

Spontaneous pneumothorax in a patient with systemic sclerosis

A 28-year-old woman developed spontaneously a right- sided pneumothorax, the leading clinical symptom of an as yet undiagnosed systemic sclerosis. The diagnosis was confirmed by Raynaud's phenomenon, microstomia, arthralgia, distal oesophageal dysfunction and antinuclear antibodies. Initial treatment with pleural suction was followed by thoracoscopy and segmental pulmonary resection. Spontaneous pneumothorax is a rare complication in patients with systemic sclerosis, most likely caused by the rupture of subpleural cysts.

Autonomic and sensorimotor neuropathy in patients with systemic lupus erythematosus and systemic sclerosis

OBJECTIVE

To determine and compare the prevalence and degree of autonomic (ANP) and sensorimotor neuropathy (SNP) in patients with systemic lupus erythematosus (SLE) and systemic sclerosis (SSc).

METHODS

Thirty-one patients with SLE and 19 with SSc were investigated. Pupillary ANP was assessed by pupillometry, cardiovascular ANP using a standardized test battery, and SNP by a standardized clinical examination.

RESULTS

In patients with SLE (SSc), 26% (10.5%) had a pathological pupillary latency time and 6.5% (13.7%) had an abnormal maximal pupillary area (p for the difference between latency time and maximal pupillary area in SLE = 0.040). Thus, patients with SLE had more often lesions of the pupillary parasympathetic portion of the autonomic nervous system. Overall prevalence of ANP was not different between the 2 groups; 29.0% in SLE and 21.1% in SSc for pupillary ANP and 9.7 and 15.7% for cardiovascular ANP, respectively. Overall prevalence of SNP was 6.5% in SLE and 21.1% in SSc. Disease activity was correlated with ANP (p = 0.008) and SNP (p = 0.020) in SLE. Kidney involvement was associated with more severe ANP in patients with SSc (p = 0.031). Duration of the disease did not correlate with any type of neuropathy.

CONCLUSION

ANP and SNP are often present in SLE and SSc. SLE and SSc differ in the pattern of ANP and SNP, which indicates that different structures and neuropathogenic mechanisms may be involved. Patients with SLE had severe pupillary ANP, probably a sign of central nervous system involvement.

In vitro superfusion method for the investigation of nerve-immune cell interaction in murine spleen

Immune defence mechanisms can be modulated by brain function. To study such interactions, an in vitro method was developed to examine the release of cytokines and norepinephrine (NE) after electrical stimulation. Slices of mouse spleen were placed in chambers with a volume of 80 microliters and superfused with culture medium. To characterize electrically evoked NE release and cell viability a suitable stimulation protocol was developed using of [3H]NE. As parameter for immune function, modulation of interleukin-6 (IL-6) release by the spleen cells brought about by electrical stimulation was investigated. Splenic [3H]NE overflow was calcium-dependent, tetrodotoxin-sensitive and elicited by 54 mM potassium. Electrically evoked [3H]NE release at 22 h was about 80% of the release at 5.3 h. Electrical stimulation substantially reduced IL-6 secretion at 6 h (control: 143.4 +/- 14.3 vs. electrical: 71.3 +/- 7.9 pg/ml/10(6) leukocytes, P = 0.0001). This effect was inhibited in a concentration-dependent manner by the beta-adrenergic antagonist propranolol (P = 0.0298, EC50 approx. 10(-7) M). In conclusion, this new technique allows long-term investigation of cell function in slices of murine spleen. In addition, these are the first in vitro data indicating the presence of a functional neuroimmunological link in murine lymphoid tissue.

Local vs Systemic Antibiotics to Decrease Wound Complications following Vertical Banded Gastroplasty: Results of a Prospective Randomized Trial

BACKGROUND: Obesity is generally regarded as one factor predisposing to wound infection. Most reports of infection rates range from I to 16% for similar procedures. In our department the wound infection rate for morbidly obese patients was 12% without perioperative antibiotics. METHODS: In a prospective randomized study we compared local gentamicin-collagen fleece application in the subcutaneous layer with patients receiving a perioperative single I.V. dose of amoxicillin-clavulanic acid 2.2 g. We examined the results of different perioperative management of antibiotics on 50 morbidly obese patients who underwent vertical banded gastroplasty from March 1993 to August 1994. The fascial, subcutaneous and skin closure technique were identical in the two groups. For both groups we used a closed-suction system to drain the bottom of the deep subcutaneous layer. On the third postoperative day, the subcutaneous drains were removed. Patients stayed in hospital an average of 10 days. They had follow-up visits after 1, 3 and 6 months, and then yearly. RESULTS: None of the 50 patients developed a wound infection, hematoma, or seroma in the hospital. During the follow-up (median 6 months), no patient developed a wound abscess. CONCLUSIONS: We believe that perioperative antibiotic management is an important factor in obtaining a low infection rate.

Immunopathology of the Lambert-Eaton myasthenic syndrome

LEMS is an antibody-mediated autoimmune disease that can occur in isolation, or as a paraneoplastic disorder in association with SCLC (60% of patients). The underlying defect is a reduction in the quantal release of the neurotransmitter ACh from the presynaptic nerve terminal at the neuromuscular junction. Experimental evidence indicates the autoantibodies are directed against nerve terminal VGCCs causing down-regulation in the number of functional channels by cross-linkage. Functional VGCCs have been detected in SCLC cell lines. In cancer-associated LEMS it appears likely that antibodies initially provoked by tumour VGCCs cross-react with VGCCs at the nerve terminal, causing the clinical disorder. Antibodies against L-, N- and P-/Q- subtypes of the calcium channels have been identified and radioimmunoassays have been developed to help diagnose the disease. Using peptide toxin 125I-omega-CmTx MVIIC to label P-/Q-type VGCC solubilised from human cerebellum, positive antibody titres can be detected in 85% of patients. However, autoantibodies in LEMS are heterogenous; the antigenic targets include different VGCC subtypes, the intracellular beta subunit and the synaptic vesicle protein synaptotagmin. The disease phenotype may reflect the diversity and titre of these different antibodies.

[Anti-Jo-1 antibodies: specific autoantibodies for polymyositis with interstitial pulmonary fibrosis. 2 case reports]

Anti-Jo-1 antibodies are rare autoantibodies, which bind and inhibit the activity of histidyl-tRNA-synthetase. They are predominantly found in a genetically and clinically distinct subset of myositis patients, presenting with interstitial alveolitis. We describe the case of a 22-year-old woman with Jo-1-syndrome with typical features of myositis, pulmonary fibrosis, nonerosive symmetric polyarthritis, Gottron's papules at the metacarpophalangeal joints and classic heliotrope discoloration of the periorbital area with edema. The patient did not respond to chloroquine, azathioprine, intravenous immunoglobulins or cyclophosphamide. Remission was finally achieved with oral methotrexate plus corticosteroids. The second case describes a 34-year-old man with myositis, who rapidly developed respiratory insufficiency after suffering from joint pain and stiffness for about 10 weeks. He responded well to cyclophosphamide pulse therapy and high-dose corticosteroids. The second case demonstrates that control of the interstitial alveolitis is most important for long-term outcome. Therefore, immunosuppressive drugs should be used along with corticosteroids as early as possible.

Antigens associated with N- and L-type calcium channels in Lambert-Eaton myasthenic syndrome

In Lambert-Eaton myasthenic syndrome neurotransmitter release is reduced by an autoimmune response directed against the calcium channel complex of the nerve terminal. Autoantibodies were detected by immunoprecipitation assays using solubilized receptors labeled with ligands selective for N-type (125I-omega conotoxin GVIA) and L-type ([3H]PN200-110) calcium channels. Sera with a high antibody titer (> 3 nM) against rat brain N-type channels contained autoantibodies that immunoprecipitated neuronal and muscle L-type channels. These IgG fractions stained a 55-kDa protein in immunoblots of purified skeletal muscle dihydropyridine receptor, suggesting that they contain autoantibodies against the beta subunit of the calcium channel. A distinct antibody population in the same fractions reacted with a nerve terminal 65-kDa protein that is unrelated to the beta subunit and displays properties similar to those of synaptotagmin.

Binding of Lambert-Eaton myasthenic syndrome IgG to synaptosomal proteins does not correlate with an inhibition of calcium uptake

The immunochemical and functional properties of IgG fractions from patients with Lambert-Eaton myasthenic syndrome (LEMS) were examined in chick and rat synaptosomes. LEMS IgG immunoprecipitated 125I-omega conotoxin GVIA (125I-omega CgTx) labeled N-type calcium channels solubilized from both tissues, and reacted with a 65 kDa protein band in immunoblots of rat synaptosomes. Depolarization-induced 45Ca2+ influx into chick synaptosomes was partially inhibited by omega CgTx, whereas influx into rat synaptosomes was insensitive to omega CgTx. No effect of LEMS sera or IgG on 45Ca2+ uptake was apparent in either preparation.

Antibodies to parvovirus B19 NS-1 protein in infected individuals

Human parvovirus B19 is the aetiological agent of the common childhood disease erythema infectiosum (fifth disease). The infection is usually benign and self-limiting, but in adults cases of severe arthritis which may persist for years have been reported. Neutralizing antibodies directed against the structural proteins are usually produced shortly after the infection. The immune response against the third major protein, the non-structural protein NS-1, of parvovirus B19 has not been characterized so far. We cloned and expressed the full-length NS-1 protein and fragments thereof in Escherichia coli. The purified recombinant proteins were used to investigate the presence of antibodies to the NS-1 protein in sera from patients with parvovirus B19 infection. Specific antibodies could be detected in sera from patients suffering from severe parvovirus B19-associated arthritis using Western blot analysis and an ELISA. Sera from patients with acute or past infection without complications did not contain detectable levels of immunoglobulin to NS-1. The use of subfragments of the NS-1 protein allowed localization of the antigenic domains in the carboxy-terminal region of the protein.

Autoantibodies, neurotoxins and the nervous system

Myasthenia gravis, the Lambert-Eaton myasthenic syndrome, and acquired neuromyotonia are three disorders of the neuromuscular junction or motor nerve that are caused by autoantibodies to ion channel proteins: acetylcholine receptors, voltage-gated calcium channels and voltage-gated potassium channels, respectively. The antibody titres can be measured using the relevant 125I-neurotoxins to label the extracted channels. Other disorders of the peripheral motor nerve are associated with antibodies to gangliosides. Sera with raised levels of anti-ganglioside antibodies have direct effects on the function of the distal motor nerve and motor nerve terminal. These conditions can be improved by therapies designed to reduce circulating antibodies. Antibodies that bind to neuronal surface antigens are proving to be of great clinical importance and interest in neurological disorders.

An improved diagnostic assay for Lambert-Eaton myasthenic syndrome

A new immunoprecipitation assay has been established for detecting antibodies to voltage-gated calcium channels (VGCCs) in Lambert-Eaton myasthenic syndrome (LEMS), using 125I-omega-conotoxin MVIIC, which binds to P-type VGCCs, to label extracts of human cerebellum. Fifty six of 66 serum samples (85%) from patients with clinically and electrophysiologically definite LEMS were positive for the presence of VGCC antibodies, defined as a titre > 3 SD above the mean for the healthy controls (n = 10). All disease controls (n = 40) were negative. This sensitive immunoassay should prove valuable in the diagnosis of LEMS.

Subacute cerebellar degeneration and Lambert-Eaton myasthenic syndrome associated with antibodies to voltage-gated calcium channels: differential effect of immunosuppressive therapy on central and peripheral defects

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Anti-neutrophil cytoplasm antibodies (ANCA) in rheumatoid arthritis: relationship to HLA-DR phenotypes, rheumatoid factor, anti-nuclear antibodies and disease severity

To investigate a possible relationship between the presence of anti-neutrophil cytoplasm antibodies (ANCA), rheumatoid factors (RF), anti-nuclear antibodies (ANA), disease severity and HLA-DR phenotypes, 46 consecutive ANCA+ and 48 ANCA-, clinically well-documented RA patients were studied for RF, ANA and HLA-DR phenotypes. The 46 ANCA+ patients showed predominantly an atypical perinuclear staining pattern (89%). ANCA positivity was associated with higher RF titres (P < 0.005) and advanced functional Steinbrocker grades III/IV (P < 0.015). ANCA+ patients were also more often positive for ANA than ANCA- patients (P < 0.008). There was no correlation between ANCA positivity and certain HLA-DR phenotypes although the frequency of DR4+ (67% vs 52%) and, in particular, of DR4+ blanks (phenotypically homozygous) was increased in ANCA+ as compared to ANCA- patients (20% vs 8%). DR4-DR1-RA patients were twice as frequent in the ANCA- than in the ANCA+ group (22.9% vs 8.7%). Correspondingly, the DR4+DR1- phenotype was increased among ANCA+ RA patients. Regarding functional Steinbrocker grades, the DR4+ phenotypes were slightly but not significantly increased in grades III and IV whereas ANCA positivity was significantly associated with severe functional Steinbrocker grades III/IV (66% ANCA+ vs 39% ANCA-, P < 0.015). ANCA positivity identified a population of RA patients with a long-standing and severe clinical course of the disease. There was no correlation between ANCA positivity and certain HLA-DR phenotypes.

Heterogeneity of calcium channel autoantibodies detected using a small-cell lung cancer line derived from a Lambert-Eaton myasthenic syndrome patient

We investigated the heterogeneity of anti-voltage-gated calcium channel (VGCC) antibodies in the Lambert-Eaton myasthenic syndrome (LEMS) using a small-cell lung carcinoma line (MB) derived from an LEMS patient. Four of 13 LEMS patients had raised titers of anti-125I-omega-conotoxin-labeled (N-type) VGCCs, measured by radioimmunoassay using line MB as the source of antigen. Antagonists for L-type (nitrendipine and nifedipine) and N-type (omega-conotoxin) VGCCs inhibited K(+)-stimulated (voltage-dependent) Ca2+ flux into this line--by 22% for L-type and 2% for N-type at maximum concentration. Inhibition by the LEMS IgGs, by contrast, ranged from 46 to 78% at a concentration of 2 mg/ml. These differing effects on Ca2+ flux inhibition by LEMS IgGs on the one hand and by L- and N-type channel antagonists on the other, taken together with the observation that many of the sera failed to react with omega-conotoxin-labeled (N-type) channels in the immunoprecipitation assay, suggest that in many LEMS patients the autoantibodies target other VGCC subtypes besides L- or N-types, and that these are important in inducing the myasthenic disorder.

Solute transport across the tonoplast of barely mesophyll vacuoles: Mg2+ determines the specificity, and ATP lipophilic amino acids the activity of the amino acid carrier

After stimulation with ATP and in the absence of divalent cations, isolated barely mesophyll vacuoles exhibited massive solute fluxes across the tonoplast, measured either as efflux of endogenous solutes or as uptake of radioactive-labeled compounds. Transported solutes were ions (particularly K+, NO3-, Cl-) and amino acids (for example, ala, arg, asp, gln, leu, met). Addition of Mg2+ in excess of added ATP inhibited fluxes of inorganic ions and of positively charged amino acids, but not, or to a smaller extent, those of neutral amino acids. Thus, Mg2+ increased the specificity of the carrier for amino acids such as alanine and glutamine. All ATP-stimulated transport processes were sensitive towards inhibition by lipophilic amino acids, for example by leucine and phenylalanine. After stimulation with sulfhydryl reagents, the inhibitory properties of Mg2+ and lipophilic amino acids were lost. These data concur with the hypothesis of a single transporter which exhibits a channel-like structure with a low degree of substrate selectivity in the absence of Mg2+, and which functions as a neutral amino acid carrier in the presence of Mg2+.