Kinesin-like protein CENP-E is upregulated in rheumatoid synovial fibroblasts

Articular destruction by invading synovial fibroblasts is a typical feature in rheumatoid arthritis (RA),. Recent data support the hypothesis that key players in this scenario are transformed-appearing synovial fibroblasts at the site of invasion into articular cartilage and bone. They maintain their aggressive phenotype toward cartilage, even when first cultured and thereafter coimplanted together with normal human cartilage into severe combined immunodeficient mice for and extended period of time. However, little is known about the upregulation of genes that leads to this aggressive fibroblast phenotype. To inhibit this progressive growth without interfering with pathways of physiological matrix remodelling, identification of pathways that operate specifically in RA synovial fibroblasts is required. In order to achieve this goal, identification of genes showing upregulation restricted to RA synovial fibroblasts is essential.

AIMS

To identify specifically expressed genes using RNA arbitrarily primed (RAP)-polymerase chain reaction (PCR) for differential display in patients with RA.

METHODS

RNA was extracted from cultured synovial fibroblasts from 10 patients with RA, four patients with osteoarthritis (OA), and one patient with psoriatic arthritis. RAP-PCR was performed using different arbitrary primers for first-strand and second-strand synthesis. First-strand and second-strand synthesis were performed using arbitrary primers: US6 (5'-GTGGTGACAG-3') for first strand, and Nuclear 1+ (5'ACGAAGAAGAG-3'), OPN28 (5'GCACCAGGGGG-3'), Kinase A2+(5'-GGTGCCTTTGG-3') and OPN24 (5'AGGGGCACCA-3') for second strand synthesis. PCR reactions were loaded onto 8 mol/l urea/6% polyacrylamide-sequencing gels and electrophoressed. Gel slices carrying the target fragment were then excised with a razor blade, eluated and reamplified. After verifying their correct size and purity on 4% agarose gels, the reamplified products derived from the single-strand confirmation polymorphism gel were cloned, and five clones per transcript were sequenced. Thereafter, a genbank analysis was performed. Quantitative reverse transcription PCRj of the segments was performed using the PCR MIMIC technique. In-situ expression of centromere kinesin-like protein-E (CENP-E) messenger (m)RNA in RA synovium was assessed using digoxigenin-labelled riboprobes, and CENP-E protein expression in fibroblasts and synovium was performed by immunogold-silver immunohistochemistry and cytochemistry. Functional analysis of CENP-E was done using different approaches (eg glucocorticoid stimulation, serum starvation and growth rate analysis of synovial fibroblasts that expressed CENP-E).

RESULTS

In RA, amplification of a distinct PCR product suitable for sequencing could be observed. The indicated complementary DNA fragment of 434 base pairs from RA mRNA corresponded to nucleotides 6615-7048 in the human centromere kinesin-like protein CENP-E mRNA (GenBank accession No. emb/Z15005). The isolated sequence shared greater than 99% nucleic acid (P=2.9e(-169)) identify with the human centromere kinesin-like protein CENP-E. Two base changes at positions 6624 (A to C) and 6739 (A to G) did not result in alteration in the amino acid sequence, and therefore 100% amino acid identity could be confirmed. The amplification of 10 clones of the cloned RAP product revealed the presence of CENP-E mRNA in every fibroblast culture examined, showing from 50% (271.000 +/- 54.000 phosphor imager arbitrary units) up to fivefold (961.000 +/- 145.000 phosphor image arbitrary units) upregulation when compared with OA fibroblasts. Neither therapy with disease-modifying antirheumatic drugs such as methotrexate, gold, resochine or cyclosporine A, nor therapy with oral steroids influenced CENP-E expression in the RA fibroblasts. Of the eight RA fibroblast populations from RA patients who were receiving disease-modifying antirheumatic drugs, five showed CENP-E upregulation; and of the eight fibroblast populations from RA patients receiving steroids, four showed CENP-E upregulation. Numerous synovial cells of the patients with RA showed a positive in situ signal for the isolated CENP-E gene segment confirming CENP-E mRNA production in rheumatoid synovium, whereas in OA synovial tissue CENP-E mRNA could not be detected. In addition, CENP-E expression was independent from medication. This was further confirmed by analysis of the effect of prednisolone on CENP-E expression, which revealed no alteration in CENP-E mRNA after exposure to different (physiological) concentrations of prednisolone. Serum starvation also could not suppress CENP-E mRNA completely.

DISCUSSION

Since its introduction in 1992, numerous variants of the differential display method and continuous improvements including RAP-PCR have proved to have both efficiency and reliability in examination of differentially regulated genes. The results of the present study reveal that RAP-PCR is a suitable method to identify differentially expressed genes in rheumatoid synovial fibroblasts. The mRNA, which has been found to be upregulated in rheumatoid synovial fibroblasts, codes for a kinesin-like motor protein named CENP-E, which was first characterized in 1991. It is a member of a family of centromere-associated proteins, of which six (CENP-A to CENP-F) are currently known. CENP-E itself is a kinetochore motor, which accumulates transiently at kinetochores in the G2 phase of the cell cycle before mitosis takes place, appears to modulate chromosome movement and spindle elongation,and is degraded at the end of mitosis. The presence or upregulation of CENP-E has never been associated with RA.The three-dimensional structure of CENP-E includes a coiled-coil domain. This has important functions and shows links to known pathways in RA pathophysiology. Coiled-coil domains can also be found in jun and fos oncogene products, which are frequently upregulated in RA synovial fibroblasts. They are also involved in DNA binding and transactivation processes resembling the situation in AP-1 (Jun/Fos)-dependent DNA-binding in rheumatoid synovium. Most interestingly, these coiled-coil motifs are crucial for the assembly of viral proteins, and the upregulation of CENP-E might reflect the influence of infectious agents in RA synovium. We also performed experiments showing that serum starvation decreased, but did not completely inhibit CENP-E mRNA expression. This shows that CENP-E is related to, but does not completely depend on proliferation of these cells. In addition, we determined the growth rate of CENP-E high and low expressors, showing that it was independent from the amount of CENP-E expression. supporting the statement that upregulation of CENP-E reflects an activated RA fibroblast phenotype. In summary, the results of the present study support the hypothesis that CENP-E, presumably independently from medication, may not only be upregulated, but may also be involved in RA pathophysiology.

Psycho-social characteristics of female alcoholics

This paper presents the survey and benefits of various questionnaires for the examination of male and female population of alcoholics. It continues to show the results of an investigation carried out at the Department for Psychiatry, Alcoholism and Other Dependences of the University Hospital "Sestre milosrdnice" in Zagreb. The aim of this study was to obtain the most accurate and recent information about alcohol dependence and the socio-psychiatric characteristic of alcoholism in the Croatian urban environment on the basis of a specially prepared questionnaire. The group of 166 treated alcoholic persons consisted of 120 males and 46 females. The age of examinees ranged between 30 to 40. The great difference in psycho-social characteristics between male and female alcoholics was confirmed. Symptomatic alcoholism observed in women was due to primary and secondary family disorders and resulted in the anxious depressive disturbance. The incidence of primary female alcoholism is on the rise. This trend can be ascribed to the changes in the life style of urban female population.

Murine cytomegalovirus induces a Sjögren's syndrome-like disease in C57Bl/6-lpr/lpr mice

OBJECTIVE

To analyze Fas and tumor necrosis factor receptor I (TNFRI) apoptosis pathways in salivary gland inflammatory disease induced by murine cytomegalovirus (MCMV) infection.

METHODS

Four different strains of mice (C57BI/6 [B6]-+/+, Fas-deficient B6-lpr/lpr, TNFRI-deficient B6-tnfr1(0/0), and B6-tnfr1(0/0)-lpr/lpr mice) were infected intraperitoneally with the Smith strain of MCMV (1 x 10(5) plaque-forming units). Viral load was determined by a plaque assay, inflammation and apoptosis by immunohistochemistry and staining with terminal dUTP nickend labeling, and autoantibodies by enzyme-linked immunosorbent assay.

RESULTS

Infectious MCMV was not detectable by day 100. Although all MCMV-infected mice developed acute sialadenitis by day 28, a chronic (>100 days), severe salivary gland inflammation and anti-Ro and anti-La antibodies developed only in the B6-lpr/lpr mice. Apoptotic cells were detected during the acute, but not the chronic, phase of inflammation.

CONCLUSION

Both Fas- and TNFRI-mediated apoptosis contribute to the clearance of MCMV-infected cells in the salivary glands. However, because Fas-mediated apoptosis is necessary for the down-modulation of the immune response, a defect in this process can lead to a postinfection, chronic inflammatory response that resembles Sjögren's syndrome.

Autoantibodies against human calpastatin in rheumatoid arthritis: epitope mapping and analysis of patient sera

Autoantibodies against calpastatin have recently been described to be highly prevalent in sera of patients with rheumatoid arthritis (RA). When the sera of 45 patients with RA were analysed for autoantibodies against calpastatin by a newly developed enzyme-linked immunosorbent assay (ELISA), only four sera (8.9%) tested positive, which is not significantly different from the frequency observed in healthy controls. Since the ELISA is based on a synthetic peptide containing the C-terminal 27 amino acids of calpastatin bound to the solid phase, this negative result might be the consequence of the small antigen used. Therefore, a systematic analysis of the epitopes for autoantibodies in calpastatin was performed using sera from RA patients and healthy individuals. Recombinant fusion proteins containing fragments of calpastatin or the complete protein were produced and sera analysed by Western blots. In the N-terminal portion (amino acids 1-369), at least two major epitopes exist, against which 65% of normal sera as well as 76% of RA sera show reactivity in Western blot assays. These epitopes are not useful for clinical diagnostics. Only five out of 45 (11.1%) RA sera reacted against the C-terminal portion (amino acids 363-708) of calpastatin, while four out of 52 (7.7%) control sera showed reactivity. Three of the five RA sera and two out of four control sera had autoantibodies against the C-terminal 27 amino acids of calpastatin. These three patient sera had already been tested positive in the ELISA. The fourth patient positive in the ELISA was Western blot negative. The differences between the group of RA patients and controls are not statistically significant. When the clinical characteristics of the four patients with autoantibodies against the carboxyl end of calpastatin were analysed, it became apparent that all four had significantly elevated C-reactive protein (>50 mg/l). This observation might indicate that calpastatin autoantibodies are found in RA patients with more active disease. Thus, while the majority of RA patients do not have an increased prevalence of calpastatin autoantibodies, it cannot be ruled out definitively that a small subgroup may be characterized by autoantibodies to the C-terminus of calpastatin.

Association of humoral markers of inflammation and dehydroepiandrosterone sulfate or cortisol serum levels in patients with chronic inflammatory bowel disease

OBJECTIVES

Dehydroepiandrosterone sulfate (DHEAS) and cortisol are multifunctional adrenal hormones with immunomodulating properties. DHEAS levels were found to be very low in chronic inflammatory diseases. This study aimed to shed more light on the interrelation between DHEAS and cortisol (and humoral markers of inflammation) in chronic inflammatory bowel disease.

METHODS

DHEAS and cortisol serum levels were measured by ELISA in the serum of 66 normal subjects, 115 patients with Crohn's disease (CD) and 64 patients with ulcerative colitis (UC). Humoral markers of inflammation and disease activity scores were assessed by standard techniques.

RESULTS

DHEAS was lower in patients with CD (p < 0.005) and UC (p < 0.005) than in controls, which was, in part, dependent on previous corticosteroid treatment (p < 0.01). In CD patients, z-normalized DHEAS was inversely correlated with blood sedimentation rate (p = 0.017). Z-normalized DHEAS was negatively correlated with interleukin-6 (IL-6) in the form of a trend (p = 0.068), and z-normalized DHEAS was significantly positively correlated with hemoglobin (p = 0.001) but not with the Crohn's disease activity index. Cortisol, however, was positively correlated with blood sedimentation rate (p = 0.034) and C-reactive protein (p = 0.006). In contrast, in UC patients no such correlation of z-normalized DHEAS or cortisol and parameters of humoral inflammatory activity or Rachmilewitz index exist.

CONCLUSIONS

DHEAS as a marker of inflammation was low in CD and UC. In CD patients, low DHEAS and high cortisol serum levels were associated with higher humoral inflammatory activity. With respect to humoral inflammatory activity in CD patients, DHEAS and cortisol seem to be inversely regulated, which may have an impact on several immune functions, such as IL-6 secretion.

Late onset primary oxalosis type I: an uncommon presentation of a rare disease

A 46-year-old woman developed rapidly worsening renal insufficiency. Extensive calcification of the kidneys was found. The patient also suffered from ischaemic neuropathy, myopathy and arthritis. In a muscle biopsy multiple calcium oxalate crystals could be demonstrated surrounded by inflammatory infiltrates. Levels of oxalate in serum were markedly elevated. Diagnosis of primary hyperoxaluria type I was made by measuring alanine/glyoxylate aminotransferase activity in a liver biopsy. The patient underwent kidney transplantation twice, but each of the transplants failed after a very short time owing to hyperacute rejection and rupture of the organ, respectively. Eventually, combined liver/kidney transplantation was successfully performed. Two years after the transplantation, both organs work with good function. This case of primary hyperoxaluria type I is remarkable for the late onset of symptoms and the extensive involvement of other organ systems in addition to the kidneys. This case presentation confirms previous reports discouraging isolated kidney transplantation for patients with primary hyperoxaluria. Only combined liver/kidney transplantation can correct the metabolic defect and may give these patients superior long-term benefit.

Air oesophagogram: a frequent, but not a specific sign of oesophageal involvement in connective tissue diseases

OBJECTIVE

This study investigates the role of the air oesophagogram in conventional chest X-rays for the diagnosis of oesophageal dysmotility in patients with connective tissue diseases.

METHODS

Fifty-one patients with connective tissue diseases were studied by oesophageal manometry and lateral and posterior-anterior chest X-rays. The presence or absence of oesophageal air on chest X-rays were evaluated separately in the upper, middle and distal segment of the oesophagus. Forty-seven chest X-rays of patients without connective tissue diseases, who had undergone manometry for the evaluation of oesophagus-related symptoms and who had normal oesophageal function, were analysed as a control.

RESULTS

A total of 23/51 patients with connective tissue diseases showed oesophageal dysfunction in manometry; 16/51 patients (31%) had air in two or more oesophageal segments on the lateral chest X-ray. There was a significant association of manometrically proven oesophageal dysmotility and air in two or three oesophageal segments (P < 0.05; sensitivity 48%, specificity 82%). However, the prevalence of an air oesophagogram showed no significant difference between patients with connective tissue diseases and the control group (10/47; 21%).

CONCLUSION

The radiological sign of an air oesophagogram is neither sensitive nor specific enough to omit oesophageal motility studies in patients with connective tissue diseases.

[Surgical treatment of aseptic bone necroses of both knee joints in antiphospholipid antibody syndrome (APL) by synovectomy, arthrolysis and arthroplasty]

A 22 year old male patient with antiphospholipid-antibody syndrome (APL) developed severe bilateral avascular necrosis of both femoral condyles. Extensive synovectomy and arthrolysis in combination with an arthroplastic remodeling of both knee joints resulted in reduction of pain and joint effusion. Therefore, synovectomy and arthroplastic remodeling might be a promising therapy to extend the period of time to prosthetic joint replacement in young patients with APL.

Human autoantibodies specific for the alpha1A calcium channel subunit reduce both P-type and Q-type calcium currents in cerebellar neurons

The pharmacological properties of voltage-dependent calcium channel (VDCC) subtypes appear mainly to be determined by the alpha1 pore-forming subunit but, whether P-and Q-type VDCCs are encoded by the same alpha1 gene presently is unresolved. To investigate this, we used IgG antibodies to presynaptic VDCCs at motor nerve terminals that underlie muscle weakness in the autoimmune Lambert-Eaton myasthenic syndrome (LEMS). We first studied their action on changes in intracellular free Ca2+ concentration [Ca2+]i in human embryonic kidney (HEK293) cell lines expressing different combinations of human recombinant VDCC subunits. Incubation for 18 h with LEMS IgG (2 mg/ml) caused a significant dose-dependent reduction in the K+-stimulated [Ca2+]i increase in the alpha1A cell line but not in the alpha1B, alpha1C, alpha1D, and alpha1E cell lines, establishing the alpha1A subunit as the target for these autoantibodies. Exploiting this specificity, we incubated cultured rat cerebellar neurones with LEMS IgG and observed a reduction in P-type current in Purkinje cells and both P- and Q-type currents in granule cells. These data are consistent with the hypothesis that the alpha1A gene encodes for the pore-forming subunit of both P-type and Q-type VDCCs.

Association of autonomic nervous dysfunction and esophageal dysmotility in systemic sclerosis

OBJECTIVE

The primary event in the pathogenesis of gastrointestinal involvement in systemic sclerosis (SSc) has been hypothesized to be an early neural lesion. We investigated the association of autonomic nervous dysfunction and esophageal involvement in SSc.

METHODS

Thirty-six consecutive patients with SSc were investigated by esophageal manometry and autonomic nervous function tests for cardiovascular and pupillary autonomic dysfunction.

RESULTS

In 27 of 36 patients, esophageal manometry showed esophageal dysfunction. Twelve patients had either pupillary (n = 6) or cardiovascular (n = 5) dysfunction or both (n = 1). All patients with autonomic dysfunction had esophageal dysfunction. Patients with autonomic dysfunction had significantly reduced mean distal esophageal contraction amplitudes compared to patients without autonomic nervous dysfunction (p < 0.05). The association of autonomic dysfunction and esophageal dysfunction was significant (p = 0.02).

CONCLUSION

Our results support the concept of a role for neurogenic defects in the development of esophageal dysfunction in SSc.

Serum dehydroepiandrosterone (DHEA) and DHEA sulfate are negatively correlated with serum interleukin-6 (IL-6), and DHEA inhibits IL-6 secretion from mononuclear cells in man in vitro: possible link between endocrinosenescence and immunosenescence

Interleukin-6 (IL-6) is one of the pathogenetic elements in inflammatory and age-related diseases such as rheumatoid arthritis, osteoporosis, atherosclerosis, and late-onset B cell neoplasia. In these diseases or during aging, the decrease in production of sex hormones such as dehydroepiandrosterone (DHEA) is thought to play an important role in IL-6-mediated pathogenetic effects in mice. In humans, we investigated the correlation of serum levels of DHEA, DHEA sulfate (DHEAS), or androstenedione (ASD) and IL-6, tumor necrosis factor-alpha, or IL-2 with age in 120 female and male healthy subjects (15-75 yr of age). Serum DHEA, DHEAS, and ASD levels significantly decreased with age (all P < 0.001), whereas serum IL-6 levels significantly increased with age (P < 0.001). DHEA/DHEAS and IL-6 (but not tumor necrosis factor-alpha or IL-2) were inversely correlated (all patients: r = -0.242/-0.312; P = 0.010/0.001). In female and male subjects, DHEA and ASD concentration dependently inhibited IL-6 production from peripheral blood mononuclear cells (P = 0.001). The concentration-response curve for DHEA was U shaped (maximal effective concentration, 1-5 x 10(-8) mol/L), which may be the optimal range for immunomodulation. In summary, the data indicate a functional link between DHEA or ASD and IL-6. It is concluded that the increase in IL-6 production during the process of aging might be due to diminished DHEA and ASD secretion. Immunosenescence may be directly related to endocrinosenescence, which, in turn, may be a significant cofactor for the manifestation of inflammatory and age-related diseases.

Association of pupillary parasympathetic hyperreflexia and systemic inflammation in patients with systemic lupus erythematosus

In chronic inflammatory diseases, cytokines stimulate the hypothalamus pituitary adrenal axis and the hypothalamus autonomic nervous system (HANS) axis. The present study was performed to find autonomic nervous function parameters in patients with systemic lupus erythematosus (SLE) which are suitable to demonstrate the activation of the HANS axis during systemic inflammation. Thirty-four patients with SLE (age 35.3 +/- 1.9 yr) were investigated by seven standardized autonomic nervous function tests. The SLEDAI and laboratory parameters of systemic inflammation were assessed by standard techniques. Pupillary latency time hyperreflexia was found in 29.4%, whereas maximal pupillary area was hyperresponsive in only 2.9%. A total of 12% had overall cardiovascular autonomic nervous hyperreflexia. Patients with latency time hyperreflexia had more severe systemic inflammation [erythrocyte sedimentation rate (ESR): P < 0.001; C-reactive protein (CRP): P = 0.0094; fibrinogen: P < 0.001; albumin: P = 0.003; antinuclear antibodies: P = 0.020]. The longitudinal study of 13 patients during 4 yr demonstrated a parallel increase and decrease in latency time percentile and ESR. SLE patients with increased systemic inflammation had an activated HANS axis which can be measured by a parasympathetic pupillary reflex test.

Performance of the SE-9000 automated haematology analyser in a laboratory serving a haematological oncology unit

The performance of the SE-9000 automated haematology analyser in a laboratory receiving a high number of abnormal specimens from haematological oncology patients was assessed according to formal protocols for the evaluation of blood cell counters. Linearity over a useful working range, precision in clinically important ranges and negligible carry-over were demonstrated in this group of patient samples confirming the results of previous investigators. The comparability of instrument derived differential leucocyte counts from both normal and distributionally abnormal samples with those obtained by visual microscopy using the NCCLS H-20 A protocol was very good. The sensitivity of flags for the detection of immature granulocytes and myeloid blast cells was high and this can be attributed to the incorporation of a new measuring channel (Immature Myeloid Information or IMI channel). The number of unrecognized abnormalities was low and when compared with the poor sensitivity of the routine 100-cell visual differential leucocyte count, the analyser was judged suitable for monitoring patients with haematological malignancies. The performance of flags such as 'left shift' and 'atypical lymphocytes' can be improved by taking into consideration distributional abnormalities such as neutrophilia and lymphocytosis. The trigger level for these flags should be adapted to the clinical need particularly in cases of neutropenia following chemotherapy, and in lymphoproliferative disorders and infection.

Autoimmunity in paraneoplastic neurological disorders

Antibodies to neuronal antigens are found in a range of different neurological disorders, both central and peripheral, and often indicate the presence of particular underlying tumours. This conference and workshop was an opportunity to discuss the clinical associations of these antibodies, the relevance of new antibody specificities, and to establish protocols for their detection.

Tonic neurogenic inhibition of interleukin-6 secretion from murine spleen caused by opioidergic transmission

The peripheral nervous system and the immune system were shown to have neurohumoral interactions. This study extends observations that demonstrated neuronal modulation of spontaneous interleukin-6 (IL-6) secretion in the spleen by norepinephrine (NE) and beta-endorphin. Spontaneous IL-6 secretion in vivo was markedly reduced by removal of macrophages with the clodronate technique. Furthermore, spontaneous IL-6 secretion was significantly inhibited at physiological concentrations of cortisol (10(-7) M). In the presence of 10(-7) M cortisol, addition of norepinephrine (NE; 10(-5) M) and isoproterenol (10(-6) and 10(-5) M) significantly increased spontaneous IL-6 secretion (+20%; P = 0.0280, P = 0.0005, and P = 0.0050, respectively). In contrast, addition of beta-endorphin significantly inhibited spontaneous IL-6 secretion in the presence of 10(-7) M cortisol (-40%; 10(-11) M, P = 0.0410; 10(-10) M, P = 0.0005). To study the effect of endogenously released transmitters on spontaneous IL-6 secretion, spleen slices were electrically stimulated with 1, 5, 10, 50, and 100 Hz. Spontaneous IL-6 secretion was markedly reduced at a frequency of 10 Hz with 10(-7) M cortisol present (P < 0.0001). This indicates that the combination of nerve firing at 5-10 Hz and physiological cortisol conditions inhibits spontaneous IL-6 secretion. Inhibition of spontaneous IL-6 secretion from spleen macrophages is most probably due to a net inhibitory effect of opioidergic transmission under these conditions.

Anti-phospholipid-antibodies in patients with relapsing polychondritis

Relapsing polychondritis (RP) is an extremely rare multisystemic disease thought to be of autoimmune origin. In order to assess if RP is associated with anti-phospholipid antibodies (aPL), clinical data and sera of 21 patients with RP were collected in a multicentre study. Concentration of anti-cardiolipin antibodies (aCL) (IgG-, IgM- and IgA-isotypes), anti-phosphatidylserine-antibodies (aPS) (IgG- and IgM-isotypes) and anti-beta-2-glycoprotein I-antibodies (a beta 2 GPI) were measured by ELISA. In eight patients aCL were found to be elevated. One patient had elevated aPS. No patient had elevated a beta 2 GPI. No patient had clinical signs and symptoms of a aPL syndrome. Interestingly, the two RP patients with the highest aPL had concomitant systemic lupus erythematosus (SLE). Therefore the presence of elevated aPL in RP is probably more closely related to an associated SLE than to RP itself. There is no convincing evidence that aPL are associated with RP.

Association of esophageal dysfunction and pulmonary function impairment in systemic sclerosis

OBJECTIVE

The aim of this study was to investigate the relationship between esophageal dysfunction and pulmonary involvement in patients with systemic sclerosis (SSc).

METHODS

Pulmonary function parameters were compared between groups of patients with and without manometric evidence for SSc-induced esophageal dysmotility.

RESULTS

Twenty-six of 43 patients (60.5%) exhibited a marked hypo- or aperistalsis of the smooth muscle portion of the esophagus. Total lung capacity, inspiratory vital capacity, and forced vital capacity were significantly lower in patients with esophageal dysfunction compared with those with normal esophageal peristalsis (p < 0.001). Patients with the diffuse form of SSc (n = 20) had significantly lower values for total lung capacity and inspiratory vital capacity compared with patients with the limited type of SSc (n = 23; p < 0.05).

CONCLUSION

There is a significant association of esophageal dysmotility with reduced lung volumes in SSc. Possible explanations for these findings are pulmonary damage due to increased gastroesophageal reflux and, more likely, simultaneous involvement of the lungs and the esophagus in the disease process.

Antibodies against the calcium channel beta-subunit in Lambert-Eaton myasthenic syndrome

The sera of patients with Lambert-Eaton myasthenic syndrome (LEMS) contain autoantibodies against several extracellular and intracellular components of the voltage-gated calcium channel (VGCC)/synaptic vesicle release complex. An example of the latter are anti-beta-subunit antibodies (anti-MysB antibodies). We constructed a full-length cDNA clone of a human VGCC beta-subunit to produce purified beta-subunit fusion protein (MysB protein). Using this protein, we demonstrated that anti-beta-subunit antibodies are present in the sera of 23% of LEMS patients and only, in low titer, in 2% of small cell lung cancer patients without LEMS. The presence of anti-beta-subunit antibodies was closely associated with high titers of P/Q- and N-type VGCC antibodies. Immunization of rats with the purified MysB protein induced high antibody titers, but no signs of neurologic dysfunction were found. We conclude that anti-beta-subunit antibodies are not likely to interfere with ion channel function, but their presence could explain the cross-reactivity of LEMS sera with several subtypes of VGCCs and the lack of correlation between anti-VGCC antibody titer and clinical severity of disease.