A multicenter comparison of MOG-IgG cell-based assays

Objectives

To compares 3 different myelin oligodendrocyte glycoprotein–immunoglobulin G (IgG) cell-based assays (CBAs) from 3 international centers.

Methods

Serum samples from 394 patients were as follows: acute disseminated encephalomyelitis (28), seronegative neuromyelitis optica (27), optic neuritis (21 single, 2 relapsing), and longitudinally extensive (10 single, 3 recurrent). The control samples were from patients with multiple sclerosis (244), hypergammaglobulinemia (42), and other (17). Seropositivity was determined by visual observation on a fluorescence microscope (Euroimmun fixed CBA, Oxford live cell CBA) or flow cytometry (Mayo live cell fluorescence-activated cell sorting assay).

Results

Of 25 samples positive by any methodology, 21 were concordant on all 3 assays, 2 were positive at Oxford and Euroimmun, and 2 were positive only at Oxford. Euroimmun, Mayo, and Oxford results were as follows: clinical specificity 98.1%, 99.6%, and 100%; positive predictive values (PPVs) 82.1%, 95.5%, and 100%; and negative predictive values 79.0%, 78.8%, and 79.8%. Of 5 false-positives, 1 was positive at both Euroimmun and Mayo and 4 were positive at Euroimmun alone.

Conclusions

Overall, a high degree of agreement was observed across 3 different MOG-IgG CBAs. Both live cell-based methodologies had superior PPVs to the fixed cell assays, indicating that positive results in these assays are more reliable indicators of MOG autoimmune spectrum disorders.

IgLON5 antibody: Neurological accompaniments and outcomes in 20 patients

OBJECTIVE

To describe the phenotypes, treatment response, and outcome of IgLON5 autoimmunity.

METHODS

Archived serum and CSF specimens from 367 patients known to harbor unclassified antibodies which stained neural synapses diffusely (mimicking amphiphysin-IgG) were reevaluated by indirect immunofluorescence assay (IFA) using a composite of mouse tissues and recombinant IgLON5-transfected cell-based assay (CBA, Euroimmun).

RESULTS

Available specimens (serum, 25; CSF, 9) from 26/367 patients (7%) had identical IFA appearance and robust IgLON5 CBA positivity. Clinical information was available for 20/26 patients; 13 were women. Median disease-onset age was 62 years (range, 46-75 years). Most patients had insidious onset and progression of neurological symptoms affecting movement and sleep predominantly. Sleep disorders were sleep-disordered breathing (11) and parasomnias (3). Brainstem disorders were gait instability (14), dysphagia (10), abnormal eye movements (7), respiratory dysfunction (6), ataxia (5), craniocervical dystonia (3), and dysarthria (3). Findings compatible with hyperexcitability included myoclonus (3), cramps (3), fasciculations (2), and exaggerated startle (2). Neuropsychiatric disorders included cognitive dysfunction (6), psychiatric symptoms (5), and seizures (1). Dysautonomia, in 9, affected bladder function (7), gastrointestinal motility (3), thermoregulation (3), and orthostatic tolerance (1). Just 2 patients had coexisting autoimmune disease. Brain MRI findings were nonspecific and CSF was noninflammatory in all tested. Seven of 9 immunotherapy-treated patients improved: 6 of those 7 were stable at last follow-up. Three untreated patients died. Each IgLON5-IgG subclass (1-4) was readily detectable in ≥80% of specimens using CBA.

CONCLUSIONS

IgLON5-IgG is diagnostic of a potentially treatable neurological disorder, where autoimmune clues are otherwise lacking.

Multiparametric serological testing in autoimmune encephalitis using computer-aided immunofluorescence microscopy (CAIFM)

Autoantibodies against neuronal cell surface antigens are tightly associated with immunotherapy-responsive autoimmune encephalitis, and a considerable number of corresponding autoantigens has been identified in recent years. Most patients initially present with overlapping symptoms, and a broad range of autoantibodies has to be considered to establish the correct diagnosis and initiate treatment as soon as possible to prevent irreversible and sometimes even life-threatening damage to the brain. Recombinant cell-based immunofluorescence allows to authentically present fragile membrane-associated surface antigens and, in combination with multiparametric analysis in the form of biochip mosaics, has turned out to be highly beneficial for parallel and prompt determination of anti-neuronal autoantibodies and comprehensive differential diagnostics. For the evaluation of recombinant cell-based IIFT, a semi-automated novel function was introduced into an established platform for computer-aided immunofluorescence microscopy. The system facilitates the microscopic analysis of the tests and supports the laboratory personnel in the rapid issuance of diagnostic findings, which is of major importance for autoimmune encephalitis patients since timely initiation of treatment may lead to their full recovery.

Enhancement of superconductivity near a nematic quantum critical point

We consider a low T_{c} metallic superconductor weakly coupled to the soft fluctuations associated with proximity to a nematic quantum critical point (NQCP). We show that (1) a BCS-Eliashberg treatment remains valid outside of a parametrically narrow interval about the NQCP, (2) the symmetry of the superconducting state (d wave, s wave, p wave) is typically determined by the noncritical interactions, but T_{c} is enhanced by the nematic fluctuations in all channels, and (3) in 2D, this enhancement grows upon approach to criticality up to the point at which the weak coupling approach breaks down, but in 3D, the enhancement is much weaker.

Indirect immunofluorescence assay for the simultaneous detection of antibodies against clinically important old and new world hantaviruses

In order to detect serum antibodies against clinically important Old and New World hantaviruses simultaneously, multiparametric indirect immunofluorescence assays (IFAs) based on biochip mosaics were developed. Each of the mosaic substrates consisted of cells infected with one of the virus types Hantaan (HTNV), Puumala (PUUV), Seoul (SEOV), Saaremaa (SAAV), Dobrava (DOBV), Sin Nombre (SNV) or Andes (ANDV). For assay evaluation, serum IgG and IgM antibodies were analyzed using 184 laboratory-confirmed hantavirus-positive sera collected at six diagnostic centers from patients actively or previously infected with the following hantavirus serotypes: PUUV (Finland, n=97); SEOV (China, n=5); DOBV (Romania, n=7); SNV (Canada, n=23); ANDV (Argentina and Chile, n=52). The control panel comprised 89 sera from healthy blood donors. According to the reference tests, all 184 patient samples were seropositive for hantavirus-specific IgG (n=177; 96%) and/or IgM (n=131; 72%), while all control samples were tested negative. In the multiparametric IFA applied in this study, 183 (99%) of the patient sera were IgG and 131 (71%) IgM positive (accordance with the reference tests: IgG, 96%; IgM, 93%). Overall IFA sensitivity for combined IgG and IgM analysis amounted to 100% for all serotypes, except for SNV (96%). Of the 89 control sera, 2 (2%) showed IgG reactivity against the HTNV substrate, but not against any other hantavirus. Due to the high cross-reactivity of hantaviral nucleocapsid proteins, endpoint titrations were conducted, allowing serotype determination in >90% of PUUV- and ANDV-infected patients. Thus, multiparametric IFA enables highly sensitive and specific serological diagnosis of hantavirus infections and can be used to differentiate PUUV and ANDV infection from infections with Murinae-borne hantaviruses (e.g. DOBV and SEOV).

Confirmed exposure to tick-borne encephalitis virus and probable human cases of tick-borne encephalitis in Central/Northern Anatolia, Turkey

Tick-borne encephalitis virus (TBEV) is the aetiological agent of tick-borne encephalitis (TBE), a potentially fatal central nervous system infection of humans. TBE is endemic in many areas of Europe and Asia; however, very scarce data on TBEV activity are available from Turkey. We aimed to identify TBEV exposure in healthy blood donors and the impact of TBEV in central nervous system infections in Central/Northern Anatolia. Two-thousand four hundred and fifty four sera, collected from blood donors at Ankara, Konya, Eskişehir and Zonguldak branches of the Turkish Red Crescent Middle Anatolia Regional Blood Center, were analysed for TBEV serosurveillance. Paired serum and cerebrospinal fluid samples from 108 patients with the diagnosis of aseptic meningitis/encephalitis of unknown aetiology were also evaluated to identify TBE and neuroborreliosis cases. Commercial enzyme-linked immunosorbent assays and indirect immunofluorescence tests were employed for antibody detection. Forty-seven donor samples (1.9%) were reactive for TBEV IgG. In 25 persons with IgG reactivity (53.1%), risk factors for tick-borne infections were revealed. One sample from Zonguldak province (1/198; 0.5%) in the Black Sea region of Turkey was confirmed to possess neutralizing antibodies via plaque reduction neutralization test. TBEV IgM was detected in 9.2% (8/108) of the patients. IgM was accompanied by IgG reactivity in two persons where, in one, recent history of a tick bite was also identified. Intrathecal antibody production for TBEV could not be demonstrated. No evidence for Borrelia infections could be found. Confirmed exposure to TBEV and/or an antigenically similar tick-borne flavivirus is documented for the first time in blood donors in Zonguldak in Northern Anatolia. Probable cases of TBE have also been identified from Central Anatolia. The epidemiology of TBEV activity in Turkey needs to be assessed and benefits of vaccination for general population, risk groups or travellers must be considered.

Evaluation of serological diagnostic test systems assessing the immune response to Japanese encephalitis vaccination

A new commercial anti-Japanese encephalitis virus IgM and IgG indirect immunofluorescence test (IIFT) was evaluated for the detection of the humoral immune response after Japanese encephalitis vaccination. The IgM IIFT was compared to two IgM capture ELISAs and the IgG IIFT was analysed in comparison to a plaque reduction neutralization test (PRNT50) and an IgG ELISA. Moreover, the course of the immune reaction after vaccination with an inactivated JEV vaccine was examined. For the present study 300 serum samples from different blood withdrawals from 100 persons vaccinated against Japanese encephalitis were used. For the IgM evaluation, altogether 78 PRNT50 positive samples taken 7 to 56 days after vaccination and 78 PRNT50 negative sera were analyzed with the Euroimmun anti-JEV IgM IIFT, the Panbio Japanese Encephalitis - Dengue IgM Combo ELISA and the InBios JE Detect IgM capture ELISA. For the IgG evaluation, 100 sera taken 56 days after vaccination and 100 corresponding sera taken before vaccination were tested in the PRNT50, the Euroimmun anti-JEV IgG IIFT, and the InBios JE Detect IgG ELISA. The Euroimmun IgM IIFT showed in comparison to the Panbio ELISA a specificity of 95% and a sensitivity of 86%. With respect to the InBios ELISA, the values were 100% and 83.9%, respectively. The analysis of the Euroimmun IgG IIFT performance and the PRNT50 results demonstrated a specificity of 100% and a sensitivity of 93.8%, whereas it was not possible to detect more than 6.6% of the PRNT50 positive sera as positive with the InBios JE Detect IgG ELISA. Thus, the IIFT is a valuable alternative to the established methods in detecting anti-JEV antibodies after vaccination in travellers and it might prove useful for the diagnosis of acutely infected persons.

[Investigation of West Nile virus in central nervous system infections of unknown etiology in Ankara, Turkey]

Arthropod-borne viral infections have recently gained considerable attention and importance as re-emerging infections in a global scale. West Nile Virus (WNV), a member of Flaviviridae, is an enveloped positive strand RNA virus that is usually transmitted to humans by the bite of Culicine mosquitoes. Although the majority of the human infections are asymptomatic, WNV may also cause febrile and neuro-invasive diseases. Seroprevalence data from Turkey indicate that WNV activity is present in Central Anatolia. In this study performed at Hacettepe University Hospital, paired serum and cerebrospinal fluid (CSF) samples from 87 adult patients with the preliminary diagnosis of aseptic meningitis/encephalitis of unknown etiology were evaluated retrospectively to identify WNV-related syndromes. Bacterial, fungal and mycobacterial cultures yielded negative results and Mycobacterium tuberculosis and Herpes simplex virus nucleic acid tests were also negative for the selected patients. Commercial enzyme-linked immunosorbent assay (ELISA)s and indirect immunofluorescence test (IIFT)s were employed for WNV IgM and IgG antibody detection (Anti-WNV Virus IgG/IgM ELISA, Anti-WNV Virus IgG/IgM IIFT; Euroimmun, Germany). Additional ELISA/IIFT assays were further performed for WNV antibody reactive samples to identify cross-reactions and/or infections with other flaviviruses and phleboviruses. All WNV antibody positive samples were also evaluated by a WNV real-time reverse-transcription polymerase chain reaction (RT-PCR) assay. WNV IgM and IgG antibodies were detected in %9.2 (8/87) and 3.4% (3/87) of the serum samples, respectively. All IgG reactive samples were negative for IgM. All sera with WNV antibody reactivity (n = 11) and the corresponding CSF samples were negative for viral RNA via RT-PCR. In 5 of the 8 WNV IgM positive subjects, sandfly fever virus IgM antibodies were detected, which was also accompanied by Dengue virus IgM positivity in one sample. In another case, intrathecal antibody synthesis against measles virus was demonstrated. Two cases (2/87; 2.3%) with WNV IgM positivity as the only serologic marker were identified as probable WNV infections and clinical features were discussed. In conclusion, in order to fully understand the impact of WNV and/or other flavivirus infections in Turkey, epidemiology and ecological features of these agents need to established.

Minimally-invasive treatment of three- and four-part fractures of the proximal humerus in elderly patients

The surgical treatment of three- and four-part fractures of the proximal humerus in osteoporotic bone is difficult and there is no consensus as to which technique leads to the best outcome in elderly patients. Between 1998 and 2004 we treated 76 patients aged over 70 years with three- or four-part fractures by percutaneous reduction and internal fixation using the Humerusblock.

A displacement of the tuberosity of > 5 mm and an angulation of > 30° of the head fragment were the indications for surgery.

Of the patients 50 (51 fractures) were available for follow-up after a mean of 33.8 months (5.8 to 81). The absolute, age-related and side-related Constant scores were recorded. Of the 51 fractures, 46 (90.2%) healed primarily. Re-displacement of fragments or migration of Kirschner wires was seen in five cases. Necrosis of the humeral head developed in four patients. In three patients a secondary arthroplasty had to be performed, in two because of re-displacement and in one for necrosis of the head. There was one case of deep infection which required a further operation and one of delayed healing.

The mean Constant score of the patients with a three-part fracture was 61.2 points (35 to 87) which was 84.9% of the score for the non-injured arm. In four-part fractures it was 49.5 points (18 to 87) or 68.5% of the score for the non-injured arm.

The Humerusblock technique can provide a comfortable and mobile shoulder in elderly patients and is a satisfactory alternative to replacement and traditional techniques of internal fixation.

[Fractures of the femoral head. A multicenter study]

BACKGROUND

Dislocated fractures of the femoral head are highly infrequent injuries. In line with this multicenter study, a follow-up examination of patients with Pipkin fractures was performed in Austrian trauma centers. The aim of this study was to evaluate the types of fractures, the kind of treatment, and the long-term results.

PATIENTS AND METHODS

In sum 46 patients were included in our study. A personal and radiological follow-up examination was carried out. The fractures were classified according to Pipkin.

RESULTS

Patients with type I fractures had the best functional outcome according to the Harris Hip Score, followed by patients with type II fractures, type IV fractures, and finally type III fractures. The result of the radiological follow-up examination showed that patients who were treated conservatively or with extirpation of the fragment had a lower grade of arthrosis. The poorest radiological outcome was seen in patients who underwent surgical treatment with open reduction and internal fixation. The implantation of a total hip prosthesis was necessary in 24% of the patients. A relevant soft tissue calcification was not recorded.

CONCLUSION

The size and location of the fractured fragment has a huge influence on the outcome. An exact anatomical reconstruction of the femoral head, especially of the weight-bearing part, is absolutely necessary.

Urogenitale Begleitverletzungen bei Beckenringfrakturen

BACKGROUND

Follow-up of patients with pelvic ring fractures and associated injuries of the lower urogenital tract was performed from January 2000 to October 2004. Analysis focused on incidence, fracture type, type of urogenital injury, associated intrapelvic lesions, mortality, and urologic outcome.

METHOD AND RESULTS

The retrospective study included 18 of 111 patients (16.2%). Nine patients had a rupture of the urethra, six a rupture of the bladder, three a rupture of the penile root, and two a gonadal defect. The type of the pelvic ring fracture according to the AO classification was type A in 1, type B in 6, and type C in 11 cases. Fifteen patients (83.3%) were followed up clinically for a mean duration of 26 months (range: 12-66 months) after trauma. Seven patients were asymptomatic concerning the urogenital injury, five had erectile dysfunction, two had urethral stenosis, in one case associated with incontinence, and one patient with bilateral defect of the testicles was under hormone substitution therapy.

CONCLUSION

Urogenital injuries, often associated with intrapelvic lesions in so-called complex pelvic trauma, are typical for high-grade pelvic ring fractures and have an essential prognostic value for the patient's morbidity and quality of life.

Deep Impact: observations from a worldwide Earth-based campaign

On 4 July 2005, many observatories around the world and in space observed the collision of Deep Impact with comet 9P/Tempel 1 or its aftermath. This was an unprecedented coordinated observational campaign. These data show that (i) there was new material after impact that was compositionally different from that seen before impact; (ii) the ratio of dust mass to gas mass in the ejecta was much larger than before impact; (iii) the new activity did not last more than a few days, and by 9 July the comet's behavior was indistinguishable from its pre-impact behavior; and (iv) there were interesting transient phenomena that may be correlated with cratering physics.

Imipramine and diet counseling with psychological support in the treatment of obese binge eaters: a randomized, placebo-controlled double-blind study

OBJECTIVE

This study with 31 obese binge eaters (body mass index [BMI] 39.5+/-8.6 kg/m(2) [SD]) was designed to assess whether diet counseling with psychological support and imipramine or placebo has an effect on the frequency of binge eating, body weight, and depression during an 8-week treatment phase. This was followed by an open medication-free phase of 6 months of continuous diet counseling with psychological support.

METHODS

Randomized double-blind placebo-controlled study of 8 weeks followed by an open phase of 6 months. Patients were evaluated in medical visits by a semistructured videotaped interview, psychometric questionnaires, and hematochemical parameters.

RESULTS

From Week 0 to 8, a significant reduction in binge frequency occurred in both treatment conditions (7.1+/-4.1 to 2.8+/-3.0 binges per week [imipramine] vs. 7.1+/-4.1 to 5.4+/-5.1 [placebo], p<.01). Patients on imipramine lost -2.2+/-1.8 kg compared to placebo-treated subjects (+0.2+/-3.3 kg, p<.001). On follow-up, only the patients initially treated with imipramine continued to lose weight (-5.1+/-2.8 kg [imipramine] vs. 2.2+/-6.8 kg [placebo], p<.001 [differences to Week 0]). While both treatment conditions were associated with significant improvements on a rater's measure of depressive symptoms (Hamilton Depression Scale) at Week 8, only the patients treated with imipramine still showed a significant improvement at Week 32. Scores on the Self Depression Rating Scale did not show a group difference but a significant reduction at Weeks 8 and 32, compared to baseline.

DISCUSSION

These results suggest that adding low-dose imipramine to diet counseling with psychological support helps patients losing weight even for at least 6 months off medication. The effect might include a psychological priming of weight loss during the double-blind phase that continues at least for half a year after stopping the drug.

Exercise training and heparin pretreatment in patients with coronary artery disease

The purpose of this study was to evaluate whether combined treatment with a cardiovascular exercise rehabilitation program and low doses of heparin can induce changes in ergometric parameters of ischemia in patients with coronary artery disease (CAD). Heparin may potentiate the development of new vessels promoted by ischemia and therefore may produce important clinical improvement. Thirty-six patients with stable CAD and evidence of myocardial ischemia on exercise testing were randomized into three groups: a control group (n = 11) received the usual medical treatment; another group (n = 11) underwent three exercise sessions per week during 12 weeks; and a third group (n = 14) undertook this exercise program and also received calcium heparin 12,500 IU subcutaneously 20 to 30 minutes before each exercise session. Pretreatment and posttreatment exercise tests were compared. Patients who underwent the rehabilitation program had an increase in exercise duration and workload at the onset of 1 mm ST-segment depression, but only patients who received calcium heparin showed a significant increase in rate-pressure product at the ST-segment ischemic threshold (p = 0.035). This result suggests that higher levels of myocardial oxygen consumption were now tolerated, a change that may be related to an improvement in myocardial perfusion.

Increased antibody titers against mycobacterial heat-shock protein 65 in patients with vasculitis and arteriosclerosis

Heat shock proteins (HSPs) are a group of highly conserved proteins that show extensive homology at the DNA and protein level among bacterial and mammalian species. Furthermore, bacterial HSPs induce specific cellular and humoral immune responses in mammals. Cross-reacting antibodies may therefore be induced in chronic infections. Recently, it has been claimed that patients with arteriosclerosis (AS) of the carotid arteries have significantly elevated antibody titers to mycobacterial HSPs. In this study, we extended the spectrum of vascular diseases and analyzed sera from patients with systemic vasculitis and systemic lupus erythematosus (SLE) for the presence of anti-HSP antibodies. Anti-HSP antibodies, tested in an ELISA with recombinant mycobacterial HSP 65, were significantly elevated in patients with vasculitis (n = 56; p < 0.01) and AS (n = 29; p < 0.0001), but only marginally in patients with SLE (n = 22; p > 0.05) compared to healthy controls (n = 90). These findings further support the concept of infection-induced immune reactions playing a pathogenic role in the development of both AS and vasculitis.