Suparaporn Wangkaew

Sensitivity and specificity of ANA and anti-dsDNA in the diagnosis of systemic lupus erythematosus: a comparison using control sera obtained from healthy individuals and patients with multiple medical problems.

BACKGROUND Antinuclear antibodies (ANA) and anti-double stranded DNA (anti-dsDNA) are often tested as a screening tool in patients with suspected systemic lupus erythematosus or connective tissue diseases. ANA can be seen in healthy controls (HC) and patients with multiple medical problems (MMP). OBJECTIVE To determine the sensitivity and specificity of ANA and anti-dsDNA in SLE patients, using sera from HC and MMP patients. METHODS Serum samples from HC, MMP and SLE patients, 100 in each group, were analyzed for the presence of ANA and anti-dsDNA, by indirect immunofluorescent assay, using a HEp-2 cell and Crithidia luciliae as substrates, respectively. RESULTS The prevalence of ANA at a titer of ≥1:80 and ≥ 1:160 was 8% and 4%, respectively, in HC; and it was 12% and 6% respectively, in MMP patients. The prevalence of anti-dsDNA was 0% in HC and 3% in MMP patients. When using HC sera for the diagnosis of SLE, the sensitivity of ANA at a titer of ≥ 1:80 and ≥ 1:160 was 98% and 90%, respectively, with specificity of 92% and 96%, respectively. The specificity decreased to 88% and 94%, respectively, when using sera from MMP patients. The specificity of anti-dsDNA was 100% and 97%, when using sera from HC and MMP patients, respectively. CONCLUSION ANA and anti-dsDNA gave high sensitivity and high specificity in patients with SLE, even when using MMP patients sera as controls. Physicians should take care in interpreting ANA and anti-dsDNA results in MMP patients who do not have signs or symptoms of SLE or connective tissue diseases.

Associated factors and psychotherapy on sleep disturbances in systemic lupus erythematosus

Sleep disturbance is a common problem in systemic lupus erythematosus (SLE) patients. This study was performed to determine the prevalence of sleep disturbance in SLE, the factors that might be associated with sleep disturbance, and the correlation between changes in clinical parameters and sleep quality over time. Fifty-six female SLE patients from a total of 497 SLE patients (11.3%) agreed to join the study. The demographic data were recorded at baseline and the clinical data, the Pittsburgh Sleep Quality Index (PSQI) and other standardized assessment tools, disease activity index, quality of life (QoL), damage index, depression, anxiety and fatigue score, were assessed three times: the first visit was at baseline, the second time was one month later, and the third time was three months after the baseline. Thirty-one of these 56 patients (55.36%) were found to have sleep disturbances. All were females with their mean ± SD age of 37.5 ± 12.3 years, and disease duration at study entry of 8.6 ± 7.3 years. There was no association between sleep disturbances and demographic data, disease activity, clinical symptoms, the presence of autoantibodies and current steroid use. In multiple logistic regression analyses, only moderate to severe depression was the independent determinant of sleep disturbances, p = 0.036. During the three-month observation, with the treatment, the changing of total PSQI score showed a significantly positive correlation with depression, anxiety, pain and QoL. Sleep disturbances in Thai SLE patients were not uncommon but a correctable condition. Depression was strongly associated with sleep disturbances. Awareness of underlying depression as well as sleep disturbances in SLE patients and treating them properly improve QoL in SLE.

High-resolution computed tomographic findings in systemic sclerosis-associated interstitial lung disease: comparison between diffuse and limited systemic sclerosis.

ObjectiveThis study aimed to compare the high-resolution computed tomographic (HRCT) findings between patients with diffuse cutaneous systemic sclerosis (DcSSc) and limited cutaneous systemic sclerosis (LcSSc) as well as to correlate the HRCT scores and the other variables. MethodsThe medical records of all patients with SSc who presented at the Rheumatology Clinic, Chiang Mai University Hospital, from March 2005 to 2010 and underwent HRCT of the chest for the presence of interstitial lung disease were retrospectively reviewed. The extent of ground glass, lung fibrosis, and honeycombing was scored. All scores were aggregated to produce a total CT perfusion score. The widest coronal esophageal diameter (WED), the maximum diameter of the main pulmonary artery (MPAD), and ascending aortic diameter (AD) were measured. The ratio of MPAD to AD (MPAD/AD) was calculated. ResultsOf the 71 patients with SSc, mean (SD) age and disease duration were 54.8 (11.8) and 3.9 (4.2) years, respectively. Of them, 69.0% were female and 67.6% were classified as having DcSSc. There were no significant differences between patients with DcSSc and LcSSc with respect to age, disease duration, New York Heart Association Functional Classification, the calculated HRCT scores, WED, and MPAD. The lung fibrosis and total CT perfusion score correlated inversely with the SpO2 (r = −0.47, P < 0.01). The honeycombing correlated positively with the New York Heart Association Functional Classification and the WED (r = 0.29 and r = 0.32, respectively, P < 0.05). ConclusionsThe HRCT scores of these patients were comparable in both subtypes of SSc. Careful evaluation of lungs and esophageal involvement should be performed irrespective of SSc subtypes. The calculated HRCT scores may be useful to assess the severity of the interstitial lung disease in SSc.

Lack of CTGF*-945C/G Dimorphism in Thai Patients with Systemic Sclerosis.

An association between connective tissue growth factor (CTGF) gene dimorphism at –945 (CTGF*-945C/G) and systemic sclerosis (SSc) has been reported with inconclusive results. We performed this study to determine whether such an association exists among Thai patients with SSc. DNA samples were taken from 50 Thai SSc patients (diffuse SSc in 39 and limited SSc in 11) and 99 healthy controls for determination of CTGF*-945C/G dimorphism by polymerase chain reaction (PCR) using specific oligonucleotide primers. The associations between the genotype frequencies, clinical manifestations and auto-antibodies were determined as well. When compared with the controls, SSc patients had no significantly higher frequencies of the GG genotype (44.0% vs 39.4%, p = 0.60), G allele (63.0% vs 65.2%, p = 0.80) or G phenotype (82.0% vs 90.9%, p = 1.0). There was no association between the presence of the GG genotype and clinical manifestations (pulmonary fibrosis, sclerodactyly, digital pitting scars, telangiectasia and pulmonary arterial hypertension), or the presence of auto-antibodies (anti-Scl-70, anti-SSA/Ro, and anti-RNP). In conclusion, we found no association between CTGF*-945C/G dimorphism and Thai SSc patients.

Periodontal disease in Thai patients with rheumatoid arthritis

To evaluate the prevalence and severity of periodontal disease in patients with rheumatoid arthritis (RA) who attended a rheumatology clinic in a university hospital.

An evaluation of the association of leukopenia and severe infection in patients with systemic lupus erythematosus.

BackgroundLeukopenia is a common finding in systemic lupus erythematosus (SLE) and may contribute to severe infections. ObjectivesThe objectives of this study were to determine the prevalence of leukopenia in SLE patients and examine the association between these conditions and severe infections noting the risk factor of severe infections. MethodsThis study was a prospective inception lupus cohort of newly diagnosed SLE patients seen between May 2007 and June 2011. Only cases that had been observed for a minimum of 1 year or died during the study were included. ResultsThere were 89 SLE patients (92% females), with their mean (SD) age and disease duration at the study entry of 31.7 (12.2) years and 2.4 (2.9) months. Leukopenia was found at the diagnosis in 51.6% of the cases. The cumulative prevalence of leukopenia, lymphopenia, and neutropenia was observed in 57.3%, 96.6%, and 60.7%, respectively. Persistent lymphopenia, noted continuously for more than or equal to 75% of the observation period, was found in 41.6%, but there was no persistent neutropenia. The incidence rate of severe infection was 12.4 per 100 patient-years. There was no difference of severe infection–free survival rate between patients who ever and never had leukopenia. In the multivariate analysis, using cyclophosphamide was the independent predictor for severe infection in SLE (hazard ratio, 2.73; 95% confidence interval, 1.10–6.77). ConclusionsLeukopenia was common in SLE but usually not persistent. In this study, the presence of leukopenia at any time was not the risk factor for severe infection in SLE. Cyclophosphamide was the important predictor for severe infection in SLE.

The genetic contribution of HLA‐DRB5*01:01 to systemic lupus erythematosus in Thailand

Human leucocyte antigen (HLA) study in patients with systemic lupus erythematosus (SLE) has been investigated in various countries, but the results are still inconclusive. This study was performed to investigate the association between HLA‐DR and SLE in patients in northern Thailand. HLA‐DR subtyping was performed in 70 patients with SLE and 99 normal healthy controls living in northern Thailand using the INNO‐LiPA HLA‐DR Decoder kit (Innogenetics) and MICRO SSP HLA DNA Typing kit (One Lambda) for reconfirmation. The allele frequency (AF) of DRB5*01:01 in SLE was significantly higher than in the controls [25.7% vs. 14.6%, P = 0.012, Pc = 0.048, OR = 2.02 (95%CI = 1.17–3.48)]. The AF of DRB1*15:01 and DRB1*16:02 showed a nonsignificant tendency to be higher in SLE (10.7% vs. 8.1%, and 17.9% vs. 11.1%). Interestingly, the DRB5*01:01 allele linked to DRB1*16:02 in 47.2% of SLE and 37.9% of controls, and the prevalence of the DRB1*16:02‐DRB5*01:01 haplotype was higher in the patients with SLE [12.1% vs. 5.6%, P = 0.044, OR = 2.35 (95%CI = 1.06–5.19)]. The DRB1*16:02 linked to DRB5*02:02 and *02:03 in 18.2% and 31.8% of controls, respectively, and linked to DRB5*02:03 in 32.0% of SLE patients. The frequency of DRB1*03:01 and *15:02 alleles was not increased in Thai SLE. There was no significant association between DRB5*01:01 and any auto‐antibodies or clinical manifestations of SLE. DRB5*01:01 is associated with Thai SLE, and the association is stronger than that of DRB1*15:01. The genetic contribution of DRB5*01:01 is due partially to the linkage disequilibrium between DRB1*16:02 and DRB5*01:01 in the northern Thai population.

Performance of the Existing Classification Criteria for Gout in Thai Patients Presenting With Acute Arthritis

Abstract Currently, there are 5 existing classification criteria for gout: the Rome, New York, American Rheumatism Association (ARA), Mexico, and Netherlands criteria. This study was carried out to determine the performance of these classification criteria in Thai patients presenting with acute arthritis. All consecutive patients presenting with acute arthritis and being consulted at the Rheumatology Unit, Chiang Mai University Hospital from January 2013 to May 2015 were invited to join the study. Gout was defined by the presence of monosodium urate crystals in the synovial fluid or tissue examined by experienced rheumatologists. The 5 existing gout classification criteria were performed and evaluated in all of the patients, who were divided in subgroups of early disease (⩽2 years), established disease (>2 years), and those without tophus. There were 136 gout and 97 nongout patients. Sensitivity and specificity across all criteria ranged from 75.7% to 97.1% and 68.0% to 84.5%, respectively. Overall, the Mexico criteria had the highest sensitivity (97.1%), and the ARA survey criteria the highest specificity (84.5%), whereas the Mexico criteria performed well in early disease with sensitivity and specificity of 97.1% and 81.7%, respectively. All 5 criteria showed high sensitivity (from 76.4% to 99.1%) but low specificity (from 30.8% to 65.4%) in established disease. In patients without tophus, the sensitivity and specificity ranged from 64.1% to 95.7% and 68.8% to 85.4%, respectively. The ARA survey criteria across all groups showed consistently high specificity for gout. The 5 existing classification criteria for gout had limited sensitivity and specificity in Thai patients presenting with acute arthritis. The ARA survey criteria are the most suitable for diagnosing gout in Thai people when crystal identification is not available.

The clinically quiescent phase in early-diagnosed SLE patients: inception cohort study

OBJECTIVES The aims of this study were to evaluate the incidence of clinical quiescence in early-diagnosed SLE patients and to determine factors associated with a prolonged clinically quiescent phase. METHODS We used an inception cohort of SLE patients seen between May 2007 and June 2012. All patients were assessed for clinical quiescence [modified SLEDAI 2000 (mSLEDAI-2K) score = 0, no new features of lupus activity o increase in treatment] then evaluated for the occurrence of flare (mSLEDAI-2K increase ≥4 and increased disease activity in one or more organ systems or an increase in treatment). RESULTS Ninety-five patients (88 females) with a mean age of 33.22 years (s.d. 13.24) and mean disease duration 2.79 months (s.d. 3.19) at cohort entry were enrolled during a mean observation period of 3.04 years (s.d. 1.38). Sixty-six patients (69.5%) reached clinical quiescence within 11.31 months (s.d. 1.10) of enrolment. Thirty-six patients (54.5%) had a disease flare during the observation period. The clinically quiescent phase was 28.2 months (s.d. 3.4). Cox regression analysis revealed that age ≥25 years at diagnosis [hazard ratio (HR) 2.57 (95% CI 1.23, 5.40)] and continued antimalarial drug treatment [HR 2.80 (95% CI 1.40, 5.58)] were associated with a longer clinically quiescent phase. CONCLUSION Most early-diagnosed SLE patients could have a good prognosis. Age at diagnosis ≥25 years or continued treatment with antimalarial drugs after reaching clinical quiescence may result in a longer clinically quiescent phase. More studies are needed to elucidate the mechanism of action for these protective effects.

Distribution of HLA-DR alleles among Thai patients with rheumatoid arthritis

OBJECTIVE This study was performed to investigate the association between the HLA-DR series and rheumatoid arthritis (RA) in a Thai population. METHODS HLA-DR subtypes were determined in 100 Thai RA patients and 99 healthy controls (HC). HLA-DR typing was performed using INNO-LiPA HLA-DRB Decoder kits (Innogenetics) and reconfirmed using MICRO SSP HLA DNA Typing kits (One Lambda) for DRB1(∗)02 and (∗)04. RESULTS When compared with the HC, the RA patients had higher allele frequency (AF) of DRB1(∗)04:05 (15.00% vs 7.07%, p=0.016, pc=NS, OR=2.319, 95%CI=1.189-4.522) and DRB1(∗)10:01 (3.00% vs 0%, p=0.030, pc=NS), respectively. The DRB1(∗)09:01 was slightly higher in the RA patients, without statistical significance. The AF of the shared epitope (SE) alleles (HLA-DRB1(∗)01:01, (∗)04:01, (∗)04:05 and (∗)10:01) was significantly higher in the RA patients (18.50% vs 7.58%, p=0.002, pc=0.046, OR=2.769, 95%CI=1.466-5.231, 99%CI=1.201-6.388). The AF of HLA-DRB4(∗)01 also increased significantly more in the RA patients (40.50% vs 25.76%, p=0.002, pc=0.002, OR=1.962, 95%CI=1.282-3.003, 99%CI=1.121-3.433). The HLA-DRB3(∗)03:01 was significantly lower in the RA patients (6.00% vs 14.14%, p=0.008, pc=0.023, OR=0.388, 95%CI=0.191-0.786, 99%CI=0.153-0.982). CONCLUSION In the presence of SE, the DRB1(∗)04:05 and HLA-DRB4(∗)01 were associated with RA, and the DRB3(∗)03:01 would be a protective allele against RA in a Thai population.