Failure of sterilization in a dental outpatient facility: Investigation, risk assessment, and management

In 2017, an incident of failed sterilization of dental instruments occurred at a large dental outpatient facility in Singapore. We aim to describe findings of the investigation of the sterilization breach incident, factors related to risk of viral transmission to the potentially affected patients, and the contact tracing process, patient management, and blood test results at a 6-month follow-up. A full assessment of the incident was immediately carried out. The factors related to risk of viral transmission due to affected instruments were analyzed using 3 keys points: breached step(s) and scale of the incident, prevalence of underlying bloodborne diseases and immunity in the Singapore population, health status of potential source patients, and type of dental procedure performed, and health status of affected patients and type of dental procedure received. Up to 72 affected instrument sets were used in 714 potentially affected patients who underwent noninvasive dental procedures. The investigation revealed that there was a lapse in the final step of steam sterilization, resulting in the use of incompletely sterilized items. The assessment determined that there was an extremely low risk of bloodborne virus transmission of diseases to the patients. At the 6-month follow-up, there were no infected/colonized cases found related to the incident. Lapses in the sterilization process for medical and dental instruments can happen, but a risk assessment approach is useful to manage similar incidents. Quick response and proper documentation of the sterilization process can prevent similar incidents.

Structure-activity relationship of new antimalarial 1-aryl-3-susbtituted propanol derivatives: Synthesis, preliminary toxicity profiling, parasite life cycle stage studies, target exploration, and targeted delivery

Design, synthesis, structure-activity relationship, cytotoxicity studies, in silico drug-likeness, genotoxicity screening, and in vivo studies of new 1-aryl-3-substituted propanol derivatives led to the identification of nine compounds with promising in vitro (55, 56, 61, 64, 66, and 70-73) and in vivo (66 and 72) antimalarial profiles against Plasmodium falciparum and Plasmodium berghei. Compounds 55, 56, 61, 64, 66 and 70-73 exhibited potent antiplasmodial activity against chloroquine-resistant strain FCR-3 (IC₅₀s < 0.28 μM), and compounds 55, 56, 64, 70, 71, and 72 showed potent biological activity in chloroquine-sensitive and multidrug-resistant strains (IC₅₀s < 0.7 μM for 3D7, D6, FCR-3 and C235). All of these compounds share appropriate drug-likeness profiles and adequate selectivity indexes (77 < SI < 184) as well as lack genotoxicity. In vivo efficacy tests in a mouse model showed compounds 66 and 72 to be promising candidates as they exhibited significant parasitemia reductions of 96.4% and 80.4%, respectively. Additional studies such as liver stage and sporogony inhibition, target exploration of heat shock protein 90 of P. falciparum, targeted delivery by immunoliposomes, and enantiomer characterization were performed and strongly reinforce the hypothesis of 1-aryl-3-substituted propanol derivatives as promising antimalarial compounds.

Exploring the scope of new arylamino alcohol derivatives: Synthesis, antimalarial evaluation, toxicological studies, and target exploration

Synthesis of new 1-aryl-3-substituted propanol derivatives followed by structure-activity relationship, in silico drug-likeness, cytotoxicity, genotoxicity, in silico metabolism, in silico pharmacophore modeling, and in vivo studies led to the identification of compounds 22 and 23 with significant in vitro antiplasmodial activity against drug sensitive (D6 IC₅₀ ≤ 0.19 μM) and multidrug resistant (FCR-3 IC₅₀ ≤ 0.40 μM and C235 IC₅₀ ≤ 0.28 μM) strains of Plasmodium falciparum. Adequate selectivity index and absence of genotoxicity was also observed. Notably, compound 22 displays excellent parasitemia reduction (98 ± 1%), and complete cure with all treated mice surviving through the entire period with no signs of toxicity. One important factor is the agreement between in vitro potency and in vivo studies. Target exploration was performed; this chemotype series exhibits an alternative antimalarial mechanism.

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New aryl-substituted propanol derivatives (APD) show promising antimalarial activity.

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γ-amino alcohol moiety is significant antimalarial chemotype.

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Compound 22 displays excellent in vivo parasitemia reduction (98%) and complete cure.

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APD are active against drug sensitive and multidrug resistant strains.

Detergent-Mediated Formation of β-Hematin: Heme Crystallization Promoted by Detergents Implicates Nanostructure Formation for Use as a Biological Mimic

Hemozoin is a unique biomineral that results from the sequestration of toxic free heme liberated as a consequence of hemoglobin degradation in the malaria parasite. Synthetic neutral lipid droplets (SNLDs) and phospholipids were previously shown to support the rapid formation of β-hematin, abiological hemozoin, under physiologically relevant pH and temperature, though the mechanism by which heme crystallization occurs remains unclear. Detergents are particularly interesting as a template because they are amphiphilic molecules that spontaneously organize into nanostructures and have been previously shown to mediate β-hematin formation. Here, 11 detergents were investigated to elucidate the physicochemical properties that best recapitulate crystal formation in the parasite. A strong correlation between the detergent's molecular structure and the corresponding kinetics of β-hematin formation was observed, where higher molecular weight polar chains promoted faster reactions. The larger hydrophilic chains correlated to the detergent's ability to rapidly sequester heme into the lipophilic core, allowing for crystal nucleation to occur. The data presented here suggest that detergent nanostructures promote β-hematin formation in a similar manner to SNLDs and phospholipids. Through understanding mediator properties that promote optimal crystal formation, we are able to establish an in vitro assay to probe this drug target pathway.

Optimization of a multi-well colorimetric assay to determine haem species in Plasmodium falciparum in the presence of anti-malarials

Background

The activity of several well-known anti-malarials, including chloroquine (CQ), is attributed to their ability to inhibit the formation of haemozoin (Hz) in the malaria parasite. The formation of inert Hz, or malaria pigment, from toxic haem acquired from the host red blood cell of the parasite during haemoglobin digestion represents a pathway essential for parasite survival. Inhibition of this critical pathway therefore remains a desirable target for novel anti-malarials. A recent publication described the results of a haem fractionation assay used to directly determine haemoglobin, free haem and Hz in Plasmodium falciparum inoculated with CQ. CQ was shown to cause a dose-dependent increase in cellular-free haem that was correlated with decreased parasite survival. The method provided valuable information but was limited due to its low throughput and high demand on parasite starting material. Here, this haem fractionation assay has been successfully adapted to a higher throughput method in 24-well plates, significantly reducing lead times and starting material volumes.

Methods

All major haem species in P. falciparum trophozoites, isolated through a series of cellular fractionation steps were determined spectrophotometrically in aqueous pyridine (5 % v/v, pH 7.5) as a low spin complex with haematin. Cell counts were determined using a haemocytometer and a rapid novel fluorescent flow cytometry method.

Results

A higher throughput haem fractionation assay in 24-well plates, containing at most ten million trophozoites was validated against the original published method using CQ and its robustness was confirmed. It provided a minimum six-fold improvement in productivity and 24-fold reduction in starting material volume. The assay was successfully applied to amodiaquine (AQ), which was shown to inhibit Hz formation, while the antifolate pyrimethamine (PYR) and the mitochondrial electron transporter inhibitor atovaquone (Atov) demonstrated no increase in toxic cellular free haem.

Conclusions

This higher throughput cellular haem fractionation assay can easily be applied to novel anti-malarials with a significantly decreased lead time, providing a valuable tool with which to probe the mechanisms of action of both new and established anti-malarials.

Identification of β-hematin inhibitors in the MMV Malaria Box

The Malaria Box, assembled by the Medicines for Malaria Venture, is a set of 400 structurally diverse, commercially available compounds with demonstrated activity against blood-stage Plasmodium falciparum. The compounds are a representative subset of the 20,000 in vitro antimalarials identified from the high-throughput screening efforts of St. Jude Children's Research Hospital (TN, USA), Novartis and GlaxoSmithKline. In addition, a small set of active compounds from commercially available libraries was added to this group, but it has not previously been published. Elucidation of the biochemical pathways on which these compounds act is a major challenge; therefore, access to these compounds has been made available free of charge to the investigator community. Here, the Malaria Box compounds were tested for activity against the formation of β-hematin, a synthetic form of the heme detoxification biomineral, hemozoin. Further, the mechanism of action of these compounds within the malaria parasite was explored. Ten of the Malaria Box compounds demonstrated significant inhibition of β-hematin formation. In this assay, dose–response data revealed IC₅₀ values ranging from 8.7 to 22.7 μM for these hits, each of which is more potent than chloroquine (a known inhibitor of hemozoin formation). The in vitro antimalarial activity of these ten hits was confirmed in cultures of the chloroquine sensitive D6 strain of the parasite resulting in IC₅₀ values of 135–2165 nM, followed by testing in the multidrug resistant strain, C235. Cultures of P. falciparum (D6) were then examined for their heme distribution following treatment with nine of the commercially available confirmed compounds, seven of which disrupted the hemozoin pathway.

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Ten of 400 Malaria Box compounds were found to be potent β-hematin inhibitors.

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We confirmed similar in vitro antimalarial activity to results from previous screens.

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7 of the 9 commercially available hits were validated hemozoin inhibitors in culture.

Impact of 4-hydroxynonenal on matrix metalloproteinase-9 regulation in lipopolysaccharide-stimulated RAW 264.7 cells

Tissue degradation and leukocyte extravasation suggest proteolytic destruction of the extracellular matrix (ECM) during severe malaria. Matrix metalloproteinases (MMPs) play an established role in ECM turnover, and increased MMP-9 protein abundance is correlated with malarial infection. The malaria pigment hemozoin (Hz) is a heme detoxification biomineral that is produced during infection and associated with biologically active lipid peroxidation products such as 4-hydroxynonenal (HNE) adsorbed to its surface. Hz has innate immunomodulatory activity, and many of its effects can be reproduced by exogenously added HNE. Hz phagocytosis enhances MMP-9 expression in monocytes; thus, this study was designed to examine the ability of HNE to alter MMP-9 regulation in activated cells of macrophage lineage. Data show that treatment of lipopolysaccharide-stimulated RAW 264.7 cells with HNE increased MMP-9 secretion and activity. HNE treatment abolished the cognate tissue inhibitor of metalloproteinase-1 protein levels, further decreasing MMP-9 regulation. Phosphorylation of both p38 mitogen-activated protein kinase (MAPK) and c-Jun NH2-terminal kinase was induced by HNE, but only p38 MAPK inhibition lessened MMP-9 secretion. These results demonstrate the in vitro ability of HNE to cause MMP-9 dysregulation in an activated cell model. The findings may extend to myriad pathologies associated with lipid peroxidation and elevated MMP-9 levels leading to tissue damage.

Identification of β-hematin inhibitors in a high-throughput screening effort reveals scaffolds with in vitro antimalarial activity

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Hemozoin formation is a prime drug target pathway to probe for new lead compounds.

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We examined the VICB library of compounds for in vitro β-hematin inhibition.

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β-Hematin inhibitors were tested for in vitro antimalarial activity in two P. falciparum strains.

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Chemical scaffolds with target-specific and in vitro antimalarial activity were identified.

The emergence of drug resistant strains of Plasmodium spp. creates a critical need for the development of novel antimalarials. Formation of hemozoin, a crystalline heme detoxification process vital to parasite survival serves as an important drug target. The quinoline antimalarials including chloroquine and amodiaquine owe their antimalarial activity to inhibition of hemozoin formation. Though in vivo formation of hemozoin occurs within the presence of neutral lipids, the lipophilic detergent NP-40 was previously shown to serve as a surrogate in the β-hematin (synthetic hemozoin) formation process. Consequently, an NP-40 mediated β-hematin formation assay was developed for use in high-throughput screening. Here, the assay was utilized to screen 144,330 compounds for the identification of inhibitors of crystallization, resulting in 530 hits. To establish the effectiveness of these target-based β-hematin inhibitors against Plasmodiumfalciparum, each hit was further tested in cultures of parasitized red blood cells. This effort revealed that 171 of the β-hematin inhibitors are also active against the parasite. Dose–response data identified 73 of these β-hematin inhibitors have IC₅₀ values ⩽5 μM, including 25 compounds with nanomolar activity against P. falciparum. A scaffold-based analysis of this data identified 14 primary scaffolds that represent 46% of the 530 total hits. Representative compounds from each of the classes were further assessed for hemozoin inhibitory activity in P. falciparum infected human erythrocytes. Each of the hit compounds tested were found to be positive inhibitors, while a negative control did not perturb this biological pathway in culture.

The effect of comorbidity on hospital mortality in patients with SLE from an Asian tertiary hospital

Objectives

The objective of the study was to assess the disease burden of systemic lupus erythematosus (SLE) and the usefulness of the Charlson Comorbidity Index (CCI) as risk-adjusted hospital mortality predictors in patients with SLE using a hospital administrative database.

Methods

A historical cohort study of a hospital discharge database from 2004 to 2011 was used to identify cases with SLE and comorbidity using the International Statistical Classification of Diseases and Related Health Problems, ninth revision, Australian modification (ICD-9-AM) codes.

Results

Over the eight years, 841 patients met the criteria of SLE with a hospital mortality rate of 9.2%. The hospital mortality rates (2.4%, 15.7%, 25.0%, and 30.4%, respectively, p < 0.001) and hospital length of stay (geometric mean, 3.5, 5.6, 8.8, and 7.5 days, respectively, p < 0.001) were consistently increased for patients with CCI ranging from none, low, moderate to high grade, respectively. Cox proportional hazards model analysis showed that CCI (hazard ratio (HR) 7.8 high vs. none, p < 0.001) and infectious disease (HR 2.0, p = 0.016) were significant and independent predictors of hospital mortality. Similar results were also seen with hospital length of stay by zero-truncated negative binomial regression model analysis.

Conclusion

The SLE burden is high in this population. Comorbidities and infectious disease were some of the most important contributors to hospital mortality and resource utilization.

HLA-DQ A1, -DQB1 and -DRB1 gene polymorphism--in Malay type 1 diabetes mellitus patients and their use for risk prediction

HLA-DQA1, -DQB1, and -DRB1 gene polymorphism were analyzed to study type 1 DM susceptibility in Malay patients from Southeast Asia (Malaysia and Singapore). Patients showed significant increases in the occurrence of DQA1*0501 (50.7% vs. 20.4%; RR = 3.97; Pc < 0.01), DQB1*0201 (48% vs. 19.1%; RR = 3.86; Pc < 0.05), and DRB1*0301 (38.7 vs. 6.8%; RR = 8.36; 95% Pc < 0.05). Conversely, significant decreases were noted in the occurrence of DQA1*0601 (14.7% vs. 35.2%; RR = 0.33; Pc = 0.008) and DQB1*0601 (4% vs. 23.5%; RR = 0.16; Pc < 0.05) in type 1 DM patients. Using a logistic regression model, we derived a risk prediction model for type 1 DM in our indigenous Malay population based on the identified HLA genotypes. The RR for type 1 DM increases by a factor of 5.68 for every unit increase in the number of DRB1*0301 allele (P < 0.001), and decreases by a factor of 0.18 per unit increase in the number of DQB1*0601 allele (P < 0.001). After adjusting for these two HLA genotypes, DQA1*0501, DQB1*0201 and DQA1*0601 were not statistically significant as risk predictors. The lower incidence of type 1 DM in the Malay population may be contributed by the genotypic combinations of DR and DQ genes as well as the linkage disequilibria between susceptible and protective alleles.

Neuropsychiatric lupus: clinical challenges, brain-reactive autoantibodies and treatment strategies

Neurological manifestations in lupus can be due to active lupus disease affecting the brain or to other reasons. Reversible posterior leucoencephalopathy syndrome, primary lymphoma of the central nervous system, cerebral infections by bacteria (e.g. mycobacteria), viruses (e.g. JC virus), fungi (e.g. Cryptococcus) and parasites (e.g. Acanthamoeba), steroid-induced psychosis and reactive depression need to be excluded. Brain-reactive autoantibodies have been described as associating with neuropsychiatric lupus. The strongest associations described to date are with antiribosomal P protein and antiphospholipid antibodies. However these autoantibodies have not been shown to play significant roles in the pathogenesis. Treatment strategy for severe neuropsychiatric lupus include establishing definitive diagnosis, early identification and treatment of aggravating factors, appropriate symptomatic treatment, adequate immunosuppression, selective B-cell depletion and autologous haematopoietic stem cell transplant. Systematic reviews have shown that cyclophosphamide administration is superior to pulse methylprednisolone as a maintenance therapy. Mycophenolate mofetil has been shown to have modest effect and should only be considered if cyclophosphamide cannot be administered.

Cogan's syndrome with recurrent carotid and aortic aneurysms: a potentially fatal disorder mimicking Marfan syndrome

Cogan's syndrome (CS) is a rare multisystemic disease characterized by vestibuloauditory dysfunction, inflammatory eye disease and vasculitis. Aortic aneurysms due to aortitis are under-recognized in CS, and are potentially fatal, with two of eight reported cases dying from aneurysm/arterial rupture. The presence of aneurysms was not recognized antemortem in both cases, highlighting the importance of early detection to prevent this potentially fatal outcome. We report a 17-year-old Chinese male with recurrent carotid and aortic aneurysms, bilateral sensorineural hearing loss, and recurrent scleritis who was initially thought to have Marfan syndrome. The diagnosis of CS was made 4.5 years after initial presentation, during which time recurrent aneurysms due to active aortitis (with aneurysmal rupture on one occasion) necessitated four surgical procedures. Treatment with methotrexate and corticosteroids resulted in no recurrence of aneurysms over 2 years of follow-up. This case illustrates (i) the challenges in diagnosing CS when various manifestations occur separately over a relatively long time period, (ii) that detection of aortic aneurysms in young patients, especially if recurrent, should prompt investigations for vasculitis/aortitis to prevent potentially fatal aneurysm rupture, and (iii) that methotrexate and high-dose corticosteroids may be effective in preventing development of further aneurysms in CS patients.

HLA-DRB1⁎04 gene polymorphisms and expressions profiles of interleukin-18 and interleukin-18 binding protein following in vitro stimulation in human peripheral blood mononuclear cells of healthy individuals and patients with rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic arthritic condition that can lead to deformities and disabilities. Interleukin-18 (IL-18) is a proinflammatory cytokine known to play a role in the acute and chronic inflammatory phases of RA. IL-18 binding protein is the natural antagonist of IL-18 protein. We aim to identify the effect of HLA-DRB1*04 gene polymorphisms on IL-18 and IL-18BP gene expressions profiles as well as the time-course profiles following in vitro stimulation with mitogens. Peripheral blood mononuclear cells from 16 RA patients and 21 healthy controls were cultured for 1, 4, 8, 12, 24, 48 and 72 h following stimulation with either LPS or PHA. mRNA expression of IL-18 and IL 18BP were determined by quantitative real-time PCR using a comparative Ct (threshold cycle) method. IL-18 levels in supernatants were measured by enzyme-linked immunosorbent assay. Basal mRNA (4.5-fold) and protein levels of IL-18 were increased and IL-18BP mRNA expression was decreased (8-fold) in RA patients when compared to controls. Similarly, increased IL-18 levels were observed in active RA patients, whereas IL-18BP expression was increased in inactive patients. There was an increase in mRNA and protein levels of IL-18 in RA patients that peaked at 4 h and 8 h respectively following LPS stimulation. A similar profile was observed for IL-18BP; however, the expression level was higher in controls than RA patients. Persistent high production of IL-18 in RA is associated with disease progression and IL-18 BP seems to inhibit this activity.

Visual disturbances in dengue fever: an answer at last?

Visual disturbances in dengue infection are uncommon but may result in permanent visual impairment. We report a 32-year-old Chinese woman with dengue infection and she developed retinal haemorrhage, retinal vasculitis and macular detachment. Autoimmune screen revealed a low C4 complement level, possibly due to partial C4 complement deficiency. The patient was treated with steroids and there was significant improvement in her vision. Partial C4 deficiency predisposes to autoimmune disease, and patients with pre-existing low C4 levels may be susceptible to ocular complications in dengue infection. Interestingly, previous case reports of ophthalmic complications of dengue infection occurred in young female patients, who are likewise predisposed to autoimmune disease. In conclusion, in individuals predisposed to autoimmune disease (females and patients with partial C4 deficiency), dengue infection may provide the antigenic trigger for immune complex deposition and retinal vasculitis. Steroids may have an important role in the treatment of this condition.

Novel brain reactive autoantibodies: Prevalence in systemic lupus erythematosus and association with psychoses and seizures

Autoantibodies can cause neuropsychiatric manifestations in lupus patients by altering the physiological function of neuronal cells. In this study, we identified Brain Reactive Autoantibodies (BRAAs) against murine neuronal membrane proteins (M.W. 27.5 and 29.5 kD) and found them correlating with psychosis and/or seizures in lupus patients. They were specific to neuronal membrane tissues of mammalian origin and are significantly associated with psychosis and/or seizures (p<0.0001). These membrane proteins mass spectrometry profiles did not match to any published protein sequences. These BRAAs may play important roles in the pathophysiology of neuropsychiatric lupus.

PCR-RFLP genotyping for exon 1 and promoter region mutations of the human mannose binding lectin (MBL-2) gene

The Mannose Binding Lectin (MBL) plays an important role in innate immunity and its genetic deficiencies are associated with frequent and prolonged infections. Serum MBL determination may not accurately detect acute phase protein levels and it is also difficult to detect dysfunctional protein. Genotyping of the exon 1 and promoter regions in the MBL gene will provide useful information on the presence of deficiencies in patients. A reproducible PCR-RFLP method is described to accurately detect genotypes of exon 1 and polymorphic haplotypes of the promoter region in the MBL gene.

Discriminative ability of the Short-Form 36 Health Survey: A tale of two versions

BACKGROUND AND OBJECTIVES

Previous studies suggested that the Chinese version of the Short-Form 36 Health Survey (SF-36) had smaller variability in the physical functioning (PF) and physical component summary (PCS) scores than the English SF-36. This may translate into differences in discriminative ability and sample size requirement.

MATERIALS AND METHODS

Data were drawn from a community-based survey and a randomised crossover study of Singaporeans bilingual in the Chinese and English languages. The abilities of the two PF and PCS versions in discriminating subjects who reported chronic illness and acute disease symptoms versus those who did not were compared.

RESULTS

In all four comparisons (i.e. two health criteria in two studies) the Chinese version of PF showed a larger effect size than the English version. In three out of four comparisons the Chinese version of PCS showed a larger effect size than the English version.

CONCLUSIONS

The Chinese version appeared more efficient in detecting a statistically significant difference between groups. Other factors being the same, the Chinese SF-36 may require a smaller sample size than the English SF-36 for the studies of physical aspects of health-related quality of life.

Refractory immune thrombocytopenia in systemic lupus erythematosus: response to mycophenolate mofetil

Immune thrombocytopenia (IT) is a common manifestation of systemic lupus erythematosus (SLE). Although severe IT (<20 x 10(9)/L) occurs in about 5-10% of patients, usually in the context of active disease, the absence of randomized controlled trials has not allowed the development of evidence-based guidelines for managing this condition. Conventionally, high-dose glucocorticoids are considered first-line therapy. Adjunctive medical and surgical treatments for patients with an absent or partial response to glucocorticoids have met with varying degrees of success. We describe an SLE patient with IT refractory to high-dose corticosteroids, pulse methylprednisolone and intravenous immunoglobulin therapy, whose platelet counts normalized during therapy with mycophenolate mofetil (MMF). Pending further controlled studies to confirm this observation, we suggest that MMF may be considered as a therapeutic option in the treatment of glucocorticoid-refractory immune thrombocytopenia in SLE.

Modelling Variability of Quality of Life Scores: A Study of Questionnaire Version and Bilingualism

BACKGROUND AND OBJECTIVES

Modelling variability of quality of life scores can not only improve our understanding of the characteristics of the measurement tools, but also shed light on sample size requirements. Although the English and Chinese versions of the Short Form 36 Health Survey (SF-36) are commonly considered equivalent, they have not been compared in terms of variability. Furthermore, bilingual and monolingual persons may differ in cognition and responses to questionnaires.

METHODS

In a community-based survey of quality of life in Singapore, a society where both English and Chinese are widely used and bilingualism is prevalent, 2590 respondents answered either version of the SF-36. We studied the impact of questionnaire version and bilingualism on the variability of SF-36 scores by regression modelling, with adjustment for covariates.

RESULTS

The Chinese version had smaller variances in the physical functioning (PF) and the physical component summary scores than the English version. The variance ratios (VRs) were respectively 0.32 and 0.60 (each p < 0.01), controlling for covariates. Bilingualism was not associated with variability in SF-36 scores except PF (VR = 0.78; p < 0.05).

CONCLUSIONS

As a result of a smaller variance, using the Chinese version of SF-36 among bilingual Chinese people may require a smaller sample size than using the English version.

Single-nucleotide polymorphisms of the interleukin-18 gene promoter region in rheumatoid arthritis patients: protective effect of AA genotype

Rheumatoid arthritis (RA) is a chronic arthritic condition that can lead to deformities and disabilities. Although numerous studies reported the association of human leukocyte antigen (HLA)-DRB1*04 and RA, other genes, e.g. cytokines genes, may contribute towards disease susceptibility. Interleukin-18 (IL-18) is a proinflammatory cytokine postulated to play a role in the acute and chronic inflammatory phases of RA. The IL-18 protein expression seems to be regulated by two single-nucleotide polymorphisms (SNPs) located at positions -607 and -137 in the promoter region of the gene. It is postulated that specific alleles may be associated with susceptibility to the development of RA. In the present study, we described the IL-18 gene promoter region genotypes and combined genotypes (-607/-137) in 106 RA patients and 273 unrelated healthy controls to evaluate the contributions of these alleles to RA predisposition in Chinese, Malays, and Indians. The genotyping were performed using sequence-specific polymerase chain reactions. Rheumatoid factors were assayed by enzyme-linked immunosorbent assay. Biodata were obtained through chart review. The controls had significantly higher frequency of AA genotype at position -607 when compared to RA patients. No significant differences were observed in the distribution of either allelic or genotypic frequencies at position -137. There was no association between the genotypes and the presence of rheumatoid factors. This study did not find evidence of a genetic susceptibility factor but demonstrated the novel finding that the AA genotype at position -607 is associated with a protective effect against development of RA in Chinese individuals. This protection may be mediated through inhibition of cyclic (Adenosine 3', 5'-cyclic monophosphate) AMP-responsive element (CRE)-binding protein by the disruption of the CRE consensus sequence.

Validity and reliability of the EQ-5D self-report questionnaire in Chinese-speaking patients with rheumatic diseases in Singapore

OBJECTIVE

We assessed the psychometric properties of a Singaporean Chinese version of the EQ-5D, a health-related quality of life (HRQoL) instrument.

MATERIALS AND METHODS

Consecutive outpatients with rheumatic diseases seen for routine follow-up consultations at the National University Hospital, Singapore were interviewed twice within 2 weeks using a standardised questionnaire containing the EQ-5D, the Short-Form 36 Health Survey (SF-36), the Learned Helplessness Subscale, a pain Visual Analogue Scale (VAS) and assessing demographic and psychosocial characteristics. To assess the validity of the EQ-5D, 13 hypotheses relating the EQ-5D self-classifier (5 dimensions) or visual analogue scale (EQ-VAS) to SF-36 scores or other variables were examined using the Mann-Whitney U test, Kruskal-Wallis or Spearman's correlation coefficient. Test-retest reliability was assessed using Cohen's kappa.

RESULTS

Forty-eight subjects were studied (osteoarthritis: 16; rheumatoid arthritis: 22; systemic lupus erythematosus: 8; spondyloarthropathy: 2; female: 93.8%; mean age: 56.4 years). Seven of 13 a-priori hypotheses relating EQ-5D to external variables were fulfilled, supporting the validity of the EQ-5D. For example, subjects reporting moderate or extreme problems for EQ-5D dimensions generally had lower median SF-36 scores than those without such problems. Cohen's kappa for test-retest reliability of the self-classifier ranged from 0.41 to 1.00 (n = 42; median interval: 7 days, interquartile range: 7 to 11 days).

CONCLUSIONS

The Singaporean Chinese EQ-5D self-classifier appears to be a valid measure of HRQoL in Singaporeans with rheumatic diseases; however, the reliability of the EQ-VAS requires further investigation. These data provide a basis for further studies of the Singaporean Chinese EQ-5D.

Thrombotic thrombocytopenic purpura in systemic lupus erythematosus: disease activity and the use of cytotoxic drugs

Thrombotic thrombocytopenic purpura (TTP) is a rare and occasionally fatal haematologic disorder that can coexist with systemic lupus erythematosus (SLE) and other autoimmune diseases. We identified all cases of TTP seen in our institution over a 3 year period using a computerized database. We found that SLE activity (measured by the SLE Disease Activity Index) and TTP activity ran a parallel course in three patients with coexistent SLE and TTP. TTP in these three patients, although refractory to plasmapheresis, responded to cytotoxic therapy. These observations further support an autoimmune contribution to the pathogenesis of some cases of TTP. A literature review revealed that mortality in SLE patients with more severe, refractory TTP treated with plasmapheresis and cytotoxics, may not be higher than in patients responding to plasmapheresis alone (who are likely to have milder disease). These data suggest that cytotoxics may have a role in treatment of patients with active SLE and TTP refractory to plasmapheresis.

Validity and reliability of the EQ-5D self-report questionnaire in English-speaking Asian patients with rheumatic diseases in Singapore

Validity and reliability of a Singaporean English EQ-5D self-report questionnaire (EQ-5D) were evaluated among consecutive outpatients with rheumatic diseases attending a tertiary referral hospital in Singapore (a multi-ethnic, urban Asian country). Subjects were interviewed twice within a 2-week period using a standardized questionnaire containing the EQ-5D, Short Form 36 Health Survey (SF-36) and assessing demographic and psychosocial characteristics. To assess validity of the EQ-5D, 13 hypotheses relating responses to EQ-5D dimension/Visual Analogue Scale (EQ-VAS) to SF-36 scores or other variables were examined using the Mann-Whitney test, Kruskal-Wallis test, or Spearman's correlation coefficient. Test-retest reliability was assessed using Cohen's kappa. Sixty-six subjects were studied (osteoarthritis: 9, rheumatoid arthritis: 26, systemic lupus erythematosus: 23, spondyloarthropathy: 8; female: 72.7%; mean age: 44.3 years). Ten of 13 a-priori hypotheses relating EQ-5D responses to external variables were fulfilled, supporting the validity of the EQ-SD. Cohen's kappa for test-retest reliability (n = 52) ranged from 0.29 to 0.61. The Singaporean English EQ-5D appears to be valid in measuring quality of life in Singaporeans with rheumatic diseases; however, its reliability requires further investigation. These data provide a basis for further studies assessing the validity of the EQ-5D in Singapore.

Clinical outcomes of patients with biopsy-proven lupus nephritis in NUH

OBJECTIVE

To review the clinical outcomes of Systemic Lupus Erythematosus (SLE) patients with biopsy-proven lupus nephritis with regards to the histological features and treatment.

METHOD

Patients (1) with SLE, (2) had renal biopsy in NUH for lupus nephritis, and (3) on follow-up from the period of January 1998 to April 2001, were reviewed.

RESULT

Fifty patients were reviewed with female to male ratio of 4:1. Mean age was 35.4 years. Sixty-eight percent had renal involvement at diagnosis of SLE. At least 50% had other major organ systems involvement. Forty-two patients had WHO Class IV lupus nephritis. Biopsy showed crescents in 17 patients, microangiopathy in 19, and vasculitis in two patients. All patients received prednisolone. Forty-one had IV cyclophosphamide, two had oral cyclophosphamide and seven had cyclosporin A. Azathioprine was used in 41 patients, pulse methylprednisolone in eight, IVIG in four, plasma exchange in three and mycophenolate in two patients.

OUTCOME

Forty-four percent were in complete remission, 26% in partial remission, 34% had relapsed nephritis, 4% had chronic renal failure and 12% progressed to ESRD. There were five deaths.

CONCLUSION

Renal involvement in SLE occurs early in the disease and is associated with other organ systems involvement. Only 44% were in complete remission. Thirty-four percent had relapsed. Renal survival was 88% in this cohort.

A Chinese version of the Rheumatology Attitudes Index is a valid and reliable measure of learned helplessness in patients with SLE

Despite the prognostic importance of learned helplessness (LH) in rheumatic diseases, there are no validated measures of LH in Chinese or other Asian languages. We therefore assessed the validity of a Chinese translation of the Rheumatology Attitudes Index (CRAI; a widely used measure of LH) and its Helplessness (CHS) and Internality (CIS) subscales in patients with SLE. Chinese-speaking SLE patients (n = 69) completed identical, self-administered questionnaires containing the CRAI and assessing demographic/socio-economic variables twice within 2 weeks. SLE activity, damage and quality of life were assessed using the BILAG, SLICC/ACR Damage Index and SF-36 respectively. Scale psychometric properties were assessed through Cronbach's alpha, intra-class correlations, quantifying test-retest differences, factor analysis and known-groups construct validity. Internal consistency and reliability were acceptable, with Cronbach's alpha for the CHS, CIS and CRAI being 0.70, 0.69 and 0.74, respectively. Mean differences in test-retest scores spanned 1.6-2.4% of possible scale ranges and intra class correlations ranged from 0.72 to 0.88. Factor analysis identified two major factors corresponding to the CHS and CIS subscales of the CRAI. Eight of 10 a priori hypotheses relating the CRAI and CHS to demographic, disease and quality of life variables were confirmed, supporting the construct validity of these scales. The CRAI and its helplessness subscale are valid and reliable measures of learned helplessness in Chinese-speaking SLE patients.

Immunotherapy in autoimmune diseases

Immunotherapy has the potential to modify or re-balance the immune system and hence useful in the management of autoimmune conditions. This article aims to review clinically useful immunotherapies available for treatment of autoimmune conditions, with particular emphasis on Type I diabetes mellitus, multiple sclerosis, rheumatoid arthritis and systemic lupus erythematosus. A Medline search for the period 1992 to 2002 (10 years) using the unrestricted keywords "immunotherapy AND autoimmune" was done. Full-length articles were selected for reviews based on the contents of their published abstracts. Additional Medline searches were focussed on the keywords "immunotherapy AND diabetes mellitus", "immunotherapy AND multiple sclerosis", "immunotherapy AND rheumatoid arthritis", and "immunotherapy AND systemic lupus erythematosus". Relevant publications referenced in the reviewed literature were further included for review, if not present in the original Medline search. Immunotherapy in Type I diabetes mellitus has focussed on the induction of tolerance to beta cell antigens, and in multiple sclerosis trials of anti-alpha 4 integrins and altered peptide ligand of myelin basic protein (MBP 83-99) showed initial promising results. The use of anti-cytokine therapy (anti-TNF alpha and IL-1Ra) in rheumatoid arthritis has improved the quality of life of patients with refractory disease. The use of anti-CD20 monoclonal antibody for in vivo B cells depletion and early trials of autologous peripheral stem cell transplants represent additional immunomodulatory treatment modalities for systemic lupus erythematosus patients. Better understanding of autoimmune conditions and advances in the production of humanized monoclonal antibodies, promises better immunotherapy in the near future.

Lateral temporal hyperperfusion in postictal psychosis assessed by 99mTc-HMPAO SPECT

Postictal psychosis is a rare complication of epileptic seizure characterized by reversible psychotic symptoms after flurries of seizure attack. It has been attributed to a phenomenon similar to Todd's paralysis without definitive proof. We studied regional cerebral blood flow (rCBF) of six patients with postictal psychosis by (99m)Tc-HMPAO SPECT scan. Baseline rCBF was compared with the rCBF during postictal psychosis. An asymmetry index (ASI) was calculated as 200 x [(ipsilateral ROI count density - contralateral ROI count density)/(ipsilateral ROI count density + contralateral ROI count density)] %. Significant differences could be found between ASIs during postictal psychosis and interictal state SPECT scan over the lateral temporal neocortex region (P = 0.017). Although hyperperfusion abnormality in SPECT can be found in Todd's paralysis, such findings are more commonly found in cerebral hyperactivity conditions. Taking into account the clinical characteristics of postictal psychosis, namely a preceding lucid interval and crescendo-decrescendo clinical course, these may be an alternative psychopathogenic mechanism for the development of postictal psychosis.

Measuring health-related quality of life in Singapore: normal values for the English and Chinese SF-36 Health Survey

OBJECTIVE

To determine norms for assessing Health-related Quality of Life (HRQOL) in Singapore using the Short Form 36 Health Survey (SF-36).

MATERIALS AND METHODS

Mean SF-36 scores were calculated for 24 population subgroups (categorised by age, gender, ethnicity and questionnaire language) and for subjects with self-reported co-morbid conditions using data from a community-based survey in Singapore.

RESULTS

The English and Chinese SF-36 was completed by 4122 and 1381 subjects, respectively, 58% (n = 3188) of whom had self-reported co-morbid conditions. SF-36 scores varied in subgroups differing in age, gender and ethnicity. In general, subjects with self-reported co-morbid conditions had lower SF-36 scores than those without these conditions, the magnitude of which exceeded 20 points in several instances. A method for calculation of SF-36 scores adjusted for age, gender, ethnicity and questionnaire language is described.

CONCLUSION

We present norms for English and Chinese SF-36 versions in Singapore and describe potential uses for these data in assessing HRQOL in Singapore.

A comparative study of the clinical manifestations of systemic lupus erythematosus in Caucasians in Rochester, Minnesota, and Chinese in Singapore, from 1980 to 1992

OBJECTIVE

To examine the relationship between ethnicity and major organ involvement at and after diagnosis in community-based cohorts of Caucasian and Chinese systemic lupus erythematosus (SLE) patients resident in Rochester, Minnesota, and Singapore, respectively.

METHODS

Clinical manifestations at and after diagnosis were compared in Caucasian and Chinese SLE patients. The association between ethnicity and disease manifestations at and after diagnosis was determined using logistic regression and Cox proportional hazards models, respectively, adjusting for the influence of demographic, socioeconomic, disease-related, and therapy-related factors.

RESULTS

At diagnosis, Caucasian SLE patients were 3 times more likely than Chinese SLE patients to have serositis (odds ratio [OR] 3.11, 95% confidence interval [CI] 1.01-9.71), nearly 7 times more likely to have a hematologic disorder (OR 6.95, 95% CI 2.20-21.97), and far less likely to have a malar rash (OR 0.19, 95% CI 0.07-0.54) or positive antinuclear antibodies (OR 0.11, 95% CI 0.03-0.52). Ethnicity was not associated with the prevalence of proteinuria or central nervous system (CSN) and other major organ involvement at diagnosis. After diagnosis, there was a trend toward less development of proteinuria and other major organ involvement in Caucasians (relative risk [RR] 0.47, 95% CI 0.19-1.15, and RR 0.22, 95% CI 0.05-1.04, respectively).

CONCLUSION

Chinese SLE patients are far less likely to have serositis or a hematologic disorder at diagnosis and may be more likely to develop proteinuria or CNS or other major organ involvement over the course of the disease, compared with Caucasian SLE patients. This may contribute to the increased mortality seen in Chinese SLE patients.

A community-based study of scaling assumptions and construct validity of the English (UK) and Chinese (HK) SF-36 in Singapore

Scaling assumptions and validity of the English (UK) and Chinese (HK) short form 36 health survey (SF-36) were assessed in a community-based survey of 5,503 Chinese, Malays and Indians in Singapore using the international quality of life assessment project approach of item and scale level validation. Missing data for SF-36 items and scales occurred in less than 1.0% of subjects. Item level validation of both versions generally supported assumptions underlying Likert scoring and hypothesised item-order clustering. Item level factor analysis supported the eight-scale structure of the SF-36. In scale level validation, SF-36 scale scores showed wide variability and acceptable internal-consistency reliability (Cronbach's alpha > 0.70 for six English and seven Chinese scales), conformed to hypothesised patterns and generally varied according to hypotheses in subjects known to differ in quality of life. Scale level factor analysis of both versions yielded very similar patterns of factor correlation, comparable to that found in Japan, but differing from that seen in Western populations. Taken together, these results support the validity of the English (UK) and Chinese (HK) SF-36 versions in the multi-ethnic Asian socio-cultural context of Singapore.

Validation of the Chinese SF-36 for quality of life assessment in patients with systemic lupus erythematosus

We studied the reliability and validity of the Chinese Short-Form 36 Health Survey (SF-36) in a cross sectional study of patients with systemic lupus erythematosus (SLE). Sixty-nine consecutive subjects completed a questionnaire containing the Chinese SF-36 twice within 14 d. Disease activity and damage were assessed using the British Isles Lupus Activity Group (BILAG) and SLICC/ACR Damage Index (DI) scales, respectively. Internal consistency was assessed using Cronbach's alpha, reliability using Spearman's correlation and repeatability coefficients, and relationships between SF-36, BILAG and DI scores using Spearman's correlation. The Chinese SF-36 showed high internal consistency (alpha = 0.72-0.91) and good reliability, with correlations exceeding 0.70 for 7 scales and mean scale score differences of < 2 points for 6 scales. SF-36 scores correlated weakly with BILAG scores (-0.27 to -0.41) and DI scores (-0.24 to -0.35), and subjects' mean SF-36 scores were 6-24 points lower than the general population, supporting construct validity of the SP-36. These data suggest that the Chinese SF-36 is a reliable and valid measure of quality of life in patients with SLE.

Validation of a Chinese version of the Medical Outcomes Study Family and Marital Functioning Measures in patients with SLE

The objective was to validate a Chinese translation of the Medical Outcomes Study Family and Marital Functioning Measures (FFM and MFM) in patients with systemic lupus erythematosus (SLE). Chinese-speaking SLE patients (n = 69) completed a self-administered questionnaire containing the FFM and MFM and assessing demographic and socio-economic status twice within a 2 week period. SLE activity, disease-related damage and quality of life were assessed using the BILAG, SLICC/ACR Damage Index and SF-36 Health Survey, respectively. Scale psychometric properties were assessed through factor analysis, Cronbach's alpha, quantifying test-retest differences and known-groups construct validity. Factor analysis identified 1 factor corresponding to the FFM and 2 factors corresponding to the MFM. Internal consistency for the FFM was excellent (alpha = 0.92) while that for the MFM was acceptable (alpha = 0.62). Mean (s.d.) test-retest differences were 0.06 (1.54) points for the FFM and 0.03 (2.08) points for the MFM. 11 and 10 of 13 a priori hypotheses relating the FFM and MFM, respectively, to demographic, disease and quality of life variables were confirmed, supporting the construct validity of these scales. The Chinese FFM and MFM are valid and reliable measures of family and marital functioning in Chinese-speaking SLE patients, with psychometric properties very similar to the source English version.

Central pontine myelinolysis--a rare manifestation of CNS Sjogren's syndrome

Central nervous involvement in Sjogren's syndrome (CNS-SS) is not uncommon and has a variety of manifestations. We describe a 47-year-old woman with Sjogren's syndrome who presented with distal renal tubular acidosis with severe hypokalemia and hypokalemic myopathy. She developed progressive obtundation after years of stable disease. ANA, anti-Ro antibodies were positive. Brain MRI showed a cleft in the mid pons which was hypointense on T1 and hyperintense on T2 which was considered to be classical of central pontine myelinolysis. Serial MRI showed initial enlargement of the lesion which persisted despite successful immunosuppressive therapy with pulse methylprednisolone, pulse cyclophosphamide, plasmapheresis and IVIG.

Peptide mimicking antigenic and immunogenic epitope of double-stranded DNA in systemic lupus erythematosus

Autoantibodies to double-stranded (ds) DNA are an important diagnostic marker and pathogenic factor for systemic lupus erythematosus (SLE). Identifying dsDNA mimotopes is a way to discover diagnostic and therapeutic candidates for SLE. 'Mono-specific' SLE anti-dsDNA antibodies were obtained by affinity purification using dsDNA-coupled Sepharose column. Using the anti-dsDNA antibodies to screen a phage peptide library, we were able to identify a mimotope that has a motif peptide sequence of RLTSSLRYNP. This chemically synthesized peptide could be recognized by 88% (37 out of 42) of anti-dsDNA antibody-positive SLE sera with a cut-off point at mean + 3 SD of the negative control sera at OD(492). The reaction of the peptide with SLE sera in ELISA was highly correlated with that of dsDNA (r = 0.809, P < 0.0001). Of particular interest, not only dsDNA but also single-stranded (ss) DNA and native RNA could inhibit the binding of the peptide with SLE sera, suggesting that the mimotope is shared by ds and ssDNAs as well as native RNA, whereas denatured RNA was not observed to inhibit the binding. The peptide was also able to elicit an immune response in rabbits and the anti-peptide rabbit serum was observed to cross-react with the peptide, ss and dsDNAs, and ss and dsDNAs could inhibit the binding of the anti-peptide serum and the peptide. However, the inhibition was not obtained with RNA. Our findings demonstrate the potential of the peptide mimic in diagnostic tests of SLE, and in the investigation of anti-DNA antibody origin and of DNA-anti-DNA antibody interaction.

Accuracy of medical record scoring of the SLICC/ACR damage index for systemic lupus erythematosus

OBJECTIVE

To study the accuracy of medical record scoring of the SLICC/ACR Damage Index (DI) for SLE.

METHODS

Medical record DI (MDI) scoring of 60 SLE patients by one physician was compared with prospective direct DI (DDI) scoring a median of 2 y earlier. Agreement between DDI and MDI total and organ system scores was compared using Cohen's kappa, the degree of misclassification by MDI and the significance of differences between DDI and MDI scores.

RESULTS

The mean duration of SLE at DDI scoring was 5.2 y. The median/mean (SD) DDI and MDI total scores were 0/0.78 (1.38) and 0/0. 85 (1.44). Damage was present on DDI and MDI scoring in 36.7% (22/60) and 38.3% (23/60) of patients. Qualitative MDI and DDI total scores (damage present/absent) showed good agreement (kappa=0.61, 95% CI=0.40-0.82, 18.3% misclassification). Quantitative MDI and DDI total scores (degree of damage) showed moderate agreement (kappa=0. 47, 95% CI=0.28-0.66, 36.7% misclassification). 9 of 12 MDI organ system scores misclassified <10% of subjects. There was no statistically significant difference between DDI and MDI total or organ system scores.

CONCLUSION

MDI total scoring is a good qualitative and moderate quantitative reflection of SLE related damage. MDI organ system scores are more accurate than MDI total scores.

A prospective study of factors affecting quality of life in systemic lupus erythematosus

OBJECTIVE

To prospectively identify factors influencing quality of life (QOL) over 6 months in patients with systemic lupus erythematosus (SLE).

METHODS

Ninety ethnically diverse patients with SLE completed questionnaires administered 6 months apart assessing QOL (using the Medical Outcomes Study Short Form-36) and demographic, socioeconomic, psychosocial, and behavioral factors. Disease activity, damage, and treatment were recorded at both evaluations. Multiple linear regression (adjusting for baseline health status) was used to identify factors influencing mental and physical health.

RESULTS

Improved physical health after 6 months was associated with reductions in learned helplessness (p = 0.034), improved mental health (p<0.001), longer disease duration (p = 0.009), and better physical health at baseline (p = 0.027). Improved mental health after 6 months was associated with better family support (p = 0.002), improvements in physical health (p<0.001), disease activity, and prednisolone dose (interaction term p = 0.019), less disease related damage (p<0.001), non-use of cytotoxic drugs (p = 0.02), and older age at diagnosis (p = 0.007).

CONCLUSION

Potentially modifiable psychosocial, disease, and therapy related factors influence QOL in patients with SLE.

The genetics of spondyloarthropathies

INTRODUCTION

Spondyloarthropathies are a heterogeneous group of rheumatic disorders that commonly present with axial skeleton or sacroiliac joints involvement. Ocular involvement like uveitis, iritis and conjunctivitis can be present in up to a third of the patients. Genetic factors play a part in the pathogenesis of spondyloarthropathies. Association with the HLA-B27 gene, especially that between ankylosing spondylitis and HLA-B27 antigenic positivity, is one of the strongest association seen between a disease and a Class I antigen. This paper aims to review the frequencies of HLA-B27 gene and its subtypes in different population groups, possible mechanisms leading to the development of joint inflammation and the risk it confers for development of spondyloarthropathies.

METHODS

The MEDLINE database was searched using keywords: HLA-B27, spondyloarthropathy, molecular mimicry, arthritogenic peptides, reactive arthritis and ankylosing arthritis. Related articles for selected papers were also consulted. Books on HLA-B27 and spondyloarthropathy were obtained through the NUS Medical Library's LINC system.

RESULTS

The genetic subtypes and susceptibility to development of disease vary in different population groups. Other HLA genes and non-HLA genes also play a part in the development of spondyloarthropathies, especially in those who are HLA-B27 negative. HLA-B27-positive relatives of spondyloarthritics have a higher risk of developing a similar condition. The presence of the HLA-B27 gene may serve as an aid to diagnosis or prognosis for clinicians. In juvenile arthritic patients, it is a poor prognostic factor, predicting for disease severity. It is also associated with poor outcomes for patients with anterior uveitis. However screening of asymptomatic individuals for the HLA-B27 gene is not recommended.

CONCLUSION

The polygenic nature of the disease needs further elucidation and study.

Validation of the medical outcomes study family and marital functioning measures in SLE patients in Singapore

OBJECTIVE

To validate the Medical Outcomes Study Family and Marital Functioning Measures (FMM and MFM) in a multi-ethnic, urban Asian population in Singapore.

METHODS

English speaking Chinese, Malay or Indian SLE patients (n=120) completed a self-administered questionnaire containing the FFM and MFM at baseline, after 2 weeks and after 6 months. Lupus activity, disease-related damage and quality of life were assessed using the British Isles Lupus Assessment Group (BILAG), Systemic Lupus International Collaborating Clinics/American College of Rheumatology (SLICC/ACR) Damage Index and SF-36 Health Survey respectively. Scale psychometric properties were assessed through factor analysis, Cronbach's alpha, quantifying test-retest differences and known-groups construct validity.

RESULTS

Factor analysis of scores obtained at baseline and after 6 months identified 3 factors corresponding to the FFM (1 factor) and the MFM (2 factors). Both scales showed acceptable internal consistency, with Cronbach's alpha of 0.95 for the FFM and 0.70 for the MFM. Mean (s.d.) test-retest differences were -0.31 (3.82) points for the FFM and -0.70 (4.26) points for the MFM. Eleven out of 13 a priori hypotheses relating both the FFM and MFM to demographic, disease and quality of life variables were confirmed, supporting the construct validity of these scales.

CONCLUSION

The FFM and MFM are valid and reliable measures of family and marital functioning in a multi-ethnic cohort of Asian SLE patients in Singapore.

The Rheumatology Attitudes Index and its helplessness subscale are valid and reliable measures of learned helplessness in Asian patients with systemic lupus erythematosus

OBJECTIVE

To assess the internal consistency, reliability, and construct validity of the Rheumatology Attitudes Index (RAI) and its subscales in a cohort of Asian patients with systemic lupus erythematosus (SLE).

METHODS

English speaking ethnic Chinese, Malay, or Indian patients with SLE (n = 120) seen at a rheumatology unit completed a questionnaire containing the RAI twice within a 2 week period. Lupus activity was assessed using the British Isles Lupus Activity Group (BILAG) score, disease related damage using the Systemic Lupus International Collaborating Clinics/American College of Rheumatology (SLICC/ACR) damage index, and quality of life using the Medical Outcome Survey Short Form 36 Health Survey (SF-36). Factor analysis and Cronbach's alpha were used to study the psychometric properties of the RAI. The magnitude of test-retest differences was assessed using the method of Bland and Altman. Relationships between the RAI, its helplessness (HS) and internality (IS) subscales, and BILAG, SLICC/ACR damage index and SF-36 scores were studied using Spearman's rank correlation.

RESULTS

Factor analysis (n = 105) identified 2 factors corresponding to the HS and IS subscales of the RAI. All scales showed acceptable internal consistency, with Cronbach's alpha of 0.64 for the HS, 0.77 for the IS, and 0.74 for the RAI. Mean (SD) test-retest differences were 0.85 (3.96) points for the HS (n = 86), 0.81 (4.44) points for the IS (n = 85), and 1.46 (7.88) points for the RAI (n = 74). Six of 10 hypotheses relating the RAI and HS to demographic, disease, and quality of life variables were confirmed, supporting the construct validity of these scales.

CONCLUSION

The RAI and its helplessness subscale are valid and reliable measures of learned helplessness in a multiethnic cohort of Asian patients with SLE in Singapore.

Peripheral neuropathy in systemic lupus erythematosus

The prevalence of clinically apparent peripheral neuropathy in systemic lupus erythematosus is reported to be between 2% to 18%. The purpose of this prospective case-control study was to determine the prevalence of peripheral neuropathy (PN) using electrodiagnostic criteria. Subgroup analysis was performed to determine whether PN correlated with disease activity, renal involvement, or serum immune markers. Fifty-four systemic lupus erythematosus patients and 30 controls were recruited in the study. The right median, ulnar, peroneal, tibial, and sural sensory and motor nerve conduction studies were obtained. PN in our study was defined as any abnormal values in motor and sensory distal latency, sensory action potential, motor action potential, or conduction velocity affecting 2 or more nerves. Of the 54 patients studied, PN was present in 15 patients (27.8%) of which 4 were symptomatic. There was a significant correlation between PN and anti-SM antibody, and there was a trend showing decreased motor and sensory action potential amplitudes in our systemic lupus erythematosus group compared to the controls. This observation was also seen in an active disease group when compared to those with inactive disease. The amplitude of the action potential was more often affected than the distal latency, and sensory nerves were more susceptible than motor nerves. The sural sensory action potential amplitude appears to be the most sensitive indicator of PN which may be used as an index to monitor disease activity.

Validation of the MOS SF-36 for quality of life assessment of patients with systemic lupus erythematosus in Singapore

OBJECTIVE

To assess the reliability and construct validity of the Medical Outcomes Study Short Form 36 Health Survey (SF-36) in a multiracial cohort of Asian patients with lupus in Singapore.

METHODS

A cross sectional study was performed on 118 English speaking patients with lupus attending a specialist rheumatology unit between March and August 1996. Patients completed a questionnaire containing the UK standard version of the SF-36 twice within a 14 day period. All patients were assessed for disease activity using the British Isles Lupus Assessment Group score (BILAG), and for disease related damage using the Systemic Lupus International Collaborating Clinics/American College of Rheumatology (SLICC/ACR) damage index (DI). Relationships between SF-36, BILAG, and DI scores were studied using Spearman's rank correlation. Internal consistency of the SF-36 was assessed using Cronbach's alpha, and stability using the repeatability coefficient of Bland and Altman.

RESULTS

SF-36 subscales showed high internal consistency, with Cronbach's alpha coefficient ranging from 0.84 to 0.94. Test-retest reliability was acceptable, with Spearman's rank correlation >0.70 for all subscales except role-physical, and mean differences in test scores of <2 points for 5 of 8 subscales. SF-36 subscale scores were weakly correlated with BILAG scores (Spearman's p -0.37 to 0.15) and SLICC/ACR DI scores (Spearman's p -0.25 to 0.23), suggesting divergent construct validity of the SF-36.

CONCLUSION

These data suggest the SF-36 is a reliable and valid measure of the quality of life of patients with lupus in Singapore.

Ophthalmic manifestations in Asian patients with systemic lupus erythematosus

AIM OF STUDY

To determine the spectrum and prevalence of ophthalmic manifestations of systemic lupus erythematosus (SLE) in Asian patients.

METHODS

We performed a standardised ophthalmic examination on consecutive Asian patients with SLE referred from a tertiary rheumatology unit to an ophthalmology department.

RESULTS

Seventy patients were included in the study. There were 66 females (94%) and 4 males (6%). The mean (range) age of the patients was 32.9 (9-67) years. Five patients (7%) had ophthalmic symptoms while 65 (93%) were asymptomatic. Eighty-three eyes of 45 patients had abnormal Schirmer's #1 test and 27 of these eyes of 17 patients also had concomitant rose bengal staining of the cornea and/or conjunctiva. Seventeen eyes of 9 patients had retinal vascular lesions. Fourteen of these eyes had mild microangiopathic retinopathy with best-corrected visual acuity (BCVA) 6/12 or better and 3 had retinal vaso-occlusive disease with BCVA worse than 6/12. Twenty-eight eyes of 14 patients had cataract and 3 eyes of 2 patients had raised intraocular pressure. Twelve eyes of 7 patients had BCVA worse than 6/12 because of optic neuropathy (4 eyes), posterior subscapsular cataract (4 eyes), retinal vaso-occlusive disease (3 eyes) and phthisis bulbi (1 eye). None had any eyelid lesion, extraocular motility disorder or retrochiasmal disorder of vision.

CONCLUSIONS

Asymptomatic dry eye is the most common ocular finding in patients with SLE. Sight-threatening complications of SLE include retinal vaso-occlusive disease and optic neuropathy.

The effects of ethnicity on disease patterns in 472 Orientals with systemic lupus erythematosus

OBJECTIVE

To determine the effects of ethnicity on disease manifestations in Oriental patients with systemic lupus erythematosus (SLE) and to describe the risk of developing renal or central nervous system (CNS) involvement with time.

METHODS

A retrospective study of 472 patients with SLE seen at the only Rheumatology Unit in Singapore. The effect of ethnicity on selected disease manifestations at diagnosis was assessed after adjusting for demographic variables using multiple logistic regression. The probability of developing selected disease manifestations with time was determined using the Kaplan-Meier product limit method.

RESULTS

At diagnosis, Malays had a higher risk of renal or CNS involvement than Chinese (OR 2.26, 95% CI 1.21 to 4.21, and OR 3.07, 95% CI 1.01 to 9.34, respectively), and Indians a lower risk of malar rash and a higher risk of oral ulcers than Chinese (OR 0.30, 95% CI 0.13 to 0.68, and OR 2.90, 95% CI 1.45 to 7.34, respectively). The prevalence of renal or CNS involvement in the entire cohort increased with time, reaching 75.6% (95% CI 66.1% to 85.0%) and 16.7% (95% CI 11.7% to 21.6%), respectively, after 18 years of disease.

CONCLUSION

Ethnicity influenced disease manifestations at diagnosis in this cohort of Oriental patients with SLE. Renal or CNS involvement developed in previously unaffected patients up to 18 years after diagnosis, highlighting the need for continued vigilance in patients with lupus.

The sensitivity and specificity of autoantibodies to the Sm antigen in the diagnosis of systemic lupus erythematosus

The anti-Sm test is thought to be specific for the diagnosis of systemic lupus erythematosus (SLE) and is one of the American College for Rheumatology (ACR) criteria for the classification of SLE. Locally, the sensitivity and specificity of this test for the diagnosis of SLE are unknown. We therefore aim to study the sensitivity and specificity of this test in our local context. A total of 1034 patient samples that were sent for routine testing of anti-Sm antibodies over a 30-month period, were included in the study. However, only 1031 patient samples were included in the final analysis as 3 casenotes were not traceable. Clinical diagnoses were obtained through a lupus database and chart review. Quantification of the anti-Sm antibodies was by the enzyme-linked immunosorbent assay (ELISA) technique. Positive anti-Sm test results were present in 165 samples, comprising 156 (94.5%) samples from lupus patients and 9 (5.5%) having diagnoses other than SLE. These diagnoses ranged from arthritis, overlap syndrome, Raynaud's phenomenon and cardiac-related diseases. The calculated sensitivity and specificity of the anti-Sm test, using a positive cut-off value of 20 units/ml, were 39.7% and 98.6%, respectively. If the positive cut-off value is raised to 30 units/ml, the specificity rises marginally to 99.5% but the sensitivity will drop by more than 10 percentage points to 27.2%. The anti-Sm test is not useful as a screening test for lupus but a positive result is highly specific for SLE.

Clinical predictors of nephritis in systemic lupus erythematosus

We identified clinical predictors of lupus nephritis presenting more than 6 months after the diagnosis of lupus in a cohort of 335 lupus patients. Almost 24% (80/335) of patients developed nephritis more than 6 months after the diagnosis of lupus. Using a Cox proportional hazards model, we found hypertension, thrombocytopaenia and leukopaenia to be associated with lupus nephritis presenting more than 6 months after diagnosis, with adjusted relative risks of 2.5 (95% CI 1.3 to 4.7), 4.3 (95% CI 1.7 to 10.8) and 3.2 (95% CI 1.7 to 6.2) respectively. In this cohort, hypertension, thrombocytopaenia and leukopaenia were associated with lupus nephritis presenting more than 6 months after the diagnosis of lupus.

The genetics of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a disease characterised by diverse clinical manifestations and the presence of multiple autoantibodies. There are multiple aetiological factors involved in its pathogenesis. Genetic factors do play an important role and the major histocompatibility complex has been studied extensively and many human leukocyte antigen (HLA) associations have been reported. Twin and familial lupus studies confirm the importance of genetic factors in the development of SLE. Reported HLA associations range from that of HLA-DR3 in Caucasians to HLA-DR2 in Chinese, Japanese and American Blacks. These associations however may only represent linkage disequilibrium and not the actual susceptibility genes. Other non-major histocompatibility complex genes have also been reported to play important roles in the pathogenesis of lupus. The advent of molecular biological techniques has advanced the understanding of susceptibility genes in many diseases. The use of microsatellite genome scanning to study multiplex lupus families has yielded a wealth of information on clusters of susceptibility genes. The identification of these genes will be an important advance in the understanding of this complex disease.

Fatal amoebic colitis in a patient with SLE: a case report and review of the literature

Colitis in systemic lupus erythematosus (SLE) poses a diagnostic challenge as clinical, radiological and laboratory findings are often non-specific. Fulminant amoebic colitis is a rare cause of death in SLE. Early diagnosis coupled with timely surgery can reduce the mortality. The demonstration of haematophagous trophozoites in the stool is diagnostic but insensitive. Early endoscopy with adequate specimen collection is an important part of the diagnosis. Serology is both sensitive and specific but can take up to 2-4 weeks for seroconversion making it less useful in a disease that takes a rapid downhill course if treated inappropriately. We report a fatal case of colitis in a patient with SLE due to invasive amoebiasis which was complicated by Salmonella bacteraemia, disseminated intravascular coagulation, acute oliguric renal failure and adult respiratory syndrome. We also reviewed the literature on the clinical features and diagnosis of fulminant amoebic colitis. Amoebic colitis, although rare, should be considered in the differential diagnosis of lupus patients with colitis.

Systemic lupus erythematosus: initial manifestations and clinical features after 10 years of disease

We studied the initial manifestations and late features in our lupus patients. The clinical data of patients fulfilling the American College of Rheumatology criteria for systemic lupus erythematosus (SLE) were entered prospectively for newly diagnosed patients and cumulatively for those with at least 10 years of disease duration. Ninety-seven Group A (newly diagnosed; 86 females and 11 males; mean age 31 years; 83 Chinese, 11 Malays, and 3 Indians) and 58 Group B (more than 10 years disease duration; 56 females and 2 males; mean age 41 years; 50 Chinese, 5 Malays, and 3 Indians) lupus patients were studied. The commonest clinical features in Group A were: haematological (73%), arthritis (57%), malar rash (43%), renal disorder (31%) and photosensitivity (30%). Group B patients had haematological (78%), malar rash (73%), arthritis (69%), renal disorder (59%) and photosensitivity (33%). Renal disorder was significantly increased over the years (P < 0.001). Hypertension was present in 18% (Group A) and 59% (Group B) (P < 0.00001), diabetes mellitus in 5% (Group A) and 10% (Group B) (P = ns), atherosclerosis in 2% (Group A) and 7% (Group B) (P = ns). Cataract formation was not present in Group A patients but was present in 10% of Group B patients. Renal disorders and morbidity factors like hypertension and cataracts increased significantly over the years. Optimum treatment of lupus patients should therefore include close attention to these factors.