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Biomedical subjects

C S Lau

Publications and source records attributed to C S Lau.

At least 73 records · Page 4Linked to original sources
PubMed1998

Safety of hormonal replacement therapy in postmenopausal patients with systemic lupus erythematosus.

It remains controversial whether administration of exogenous estrogens is safe in systemic lupus erythematosus (SLE). The current study was undertaken to determine the effect of hormone replacement therapy (HRT) on the rate and magnitude of flares in a cohort of postmenopausal SLE patients. Thirty-four patients were prospectively followed. The frequency and severity of disease exacerbations in 11 patients who received HRT was compared with 23 patients who did not receive HRT. Our results showed that both users and non-users of HRT had a comparable age of disease onset, duration of disease, clinical manifestations, and duration of follow-up. No significant increase in the rate (0.12 relapses/patient-year in HRT group vs 0.16 relapses/patient-year in the non-HRT group, p = 0.90) or magnitude (total SLEDAI score increase during flares/patient-year in the HRT and non-HRT groups were 0.55 and 1.22, respectively, p = 0.57) of flares could be demonstrated in patients who received HRT over a median follow-up period of 35 months. We concluded that HRT appeared to be well tolerated and safe in postmenopausal SLE patients. Its potential beneficial effect may outweigh its deleterious effect on disease activity.

Adult↗
PubMed1998

Risk factors for avascular bone necrosis in systemic lupus erythematosus.

OBJECTIVE: To study the predictive factors for avascular necrosis (AVN) of bone in patients with systemic lupus erythematosus (SLE). METHOD: The records of 38 SLE patients who developed clinically apparent AVN during the course of their disease were reviewed. Information on clinical presentation, corticosteroid usage and autoantibody profiles was obtained, and comparison was made between these patients and 143 consecutive control SLE patients who did not have AVN. RESULTS: The point prevalence of AVN in our SLE population was 12%. Patients with AVN, when compared with controls, had a significantly higher incidence of neurological disease (39% vs 14%; P < 0.001) and Cushingoid body habitus after steroid treatment (79% vs 53%; P = 0.004). The highest cumulative prednisolone dose in 1 and 4 months was significantly higher in the AVN group than the controls (1.8 vs 1.1 and 4.5 vs 2.8 g, respectively; P < 0.01 in both) and showed a linear trend with the incidence of AVN (chi2 test for trend, P < 0.01 in both). Lupus anticoagulant was associated with AVN (P = 0.02, odds ratio 2.88 [1.14-7.28]). Logistic regression analysis revealed that the highest cumulative prednisolone dose administered in 4 months, the maximum and mean daily prednisolone dosage, and the lupus anticoagulant were independent risk factors for AVN. CONCLUSIONS: Corticosteroid remains the major predisposing factor for AVN in SLE. Patients who require an initial high-dose steroid for disease control are at risk of AVN, especially if they are positive for the lupus anticoagulant or develop Cushingoid habitus after steroid treatment. High-risk patients should be closely monitored so that early AVN can be diagnosed by sensitive techniques such as magnetic resonance imaging and radioisotope bone scanning.

Adolescent↗
PubMed1998

Late onset systemic lupus erythematosus in southern Chinese.

OBJECTIVE: Systemic lupus erythematosus (SLE) is a multisystem disorder that predominately affects women of the reproductive age. Onset of the disease beyond the age of 50 years is unusual. This study was undertaken to compare retrospectively the clinical and laboratory features between early and late onset (onset of disease beyond the age of 50 years) SLE patients in a Chinese population. METHODS: Case records of all SLE patients who attended our rheumatology clinics between 1971 and 1997 were reviewed. Patients with a disease onset beyond the age of 50 years were identified. One hundred consecutive SLE patients who had their disease onset before the age of 50 were recruited as controls. The presenting clinical features, autoantibody profile, number of major organs involved, number of major relapses, and the use of cytotoxic agents in the two groups of patients were obtained and compared. RESULTS: 25 patients with late onset SLE were identified. All the female patients in the late onset group were postmenopausal. The female to male ratio was 3.2 to 1, compared with 13.3 to 1 in the control group (p < 0.02). Both groups had a comparable duration of disease. There were no significant differences in the presenting features between the two groups except for a lower prevalence of malar rash (24% v 86%, p < 0.0001) and a higher prevalence of rheumatoid factor (32% v 1%, p < 0.0001) in the late onset patients. On subsequent visits, the late onset group had a lower prevalence of lupus nephritis (4% v 51%, p < 0.001), fewer major organs involved (mean number of major organs involved; 0.3 v 0.9, p < 0.02), fewer major relapses (mean number of major relapses/patient; 0.08 v 0.47, p < 0.002, number of major relapses/patient year; 0.009 v 0.12, p < 0.001), and required fewer cytotoxic agents for disease control (percentage of patients on cytotoxic agents; 32% v 79%, p < 0.002). CONCLUSION: Late onset SLE in Chinese tends to run a more benign course with fewer major organ involvement and fewer major relapses. The significantly higher incidence of male sex in late onset SLE and the milder disease course in the postmenopausal female patients suggest that oestrogen status may influence disease activity.

Adolescent↗
PubMed1998

Lack of evidence of active lytic replication of Epstein-Barr and cytomegaloviruses in patients with systemic lupus erythematosus.

OBJECTIVES: Systemic lupus erythematosus (SLE) is a multifactorial disease. Environmental factors such as viral infection(s) have been proposed as pathaetiological factors. There are particular interests in studying lymphotropic viruses such as the Epstein-Barr virus (EBV) and cytomegalovirus (CMV). Although previous case reports and in vitro studies suggested that they may have a role, there is no direct evidence that onset of SLE or disease exacerbation is associated with active infection by these viruses. Using the very sensitive polymerase chain reaction (PCR) technique, we tried to find out evidence of active replication of these viruses in patients with SLE. METHODS: Thirty-four patients with SLE were compared with matched normal controls. Eleven patients were newly diagnosed to have SLE and 18 of the 34 patients had active disease as determined by a SLE Disease Activity Index (SLEDAI) score of > or = 10 at the time of study. RESULTS: Our results showed no evidence of active replication or reactivation of EBV in the leucocytes amongst the newly diagnosed SLE patients, established SLE patients, patients with SLEDAI > or = 10, patients with SLEDAI < 10, and control subjects. There was no evidence of CMV infection in any of the subjects studied. The IgG and IgA responses against EBV early antigen (EA) and viral capsid antigen (VCA) were also studied. The IgG and IgA responses against VCA of EBV were increased in patients with SLE when compared with controls. However, there were no differences in these responses among different subgroups of patients. The mechanism of these responses was not apparent but may represent non-specific hyperimmune responses in these patients. There were no differences in the titre of IgG and IgA against EBV EA between the patient groups and controls. CONCLUSION: There is no direct evidence that either EBV or CMV plays a direct role in the onset and/or exacerbation of SLE.

Antibodies, Viral↗
PubMed1998

The use of anti-ribosomal P antibodies in the diagnosis of cerebral lupus---superiority of western blotting over enzyme-linked immunosorbent assay.

This study investigated the use of anti-ribosomal P antibodies in the diagnosis of cerebral complications of systemic lupus erythematosus using two different methods---western blotting and enzyme-linked immunosorbent assay. Anti-ribosomal P antibodies in patient serum were detected in both methods using a purified ribosomal P antigen substrate. Western blotting detected anti-ribosomal P antibodies with a 90% specificity for systemic lupus erythematosus in 56% of patients with the disease. The detection of anti-ribosomal P antibodies by western blotting in patients with systemic lupus erythematosus was significantly associated with psychosis and/or seizures; detection was positive in 90% of patients with these cerebral complications and in 41% of those without. Elevation of the level of anti-ribosomal P antibody, as measured by enzyme-linked immunosorbent assay, was 99% specific for systemic lupus erythematosus in 44% of patients with systemic lupus erythematosus that was not associated with cerebral involvement. We conclude that the measurement of anti-ribosomal P antibodies by western blotting is helpful in the diagnosis of cerebral lupus in selected patients.

Journal Article↗
PubMed1998

Acute transverse myelopathy in systemic lupus erythematosus: clinical presentation, treatment, and outcome.

OBJECTIVE: Acute transverse myelopathy (ATM) is a rare manifestation of systemic lupus erythematosus (SLE). The pathogenesis is unclear and the optimal management strategy is uncertain because of the lack of controlled trials. In this study, the clinical presentation, autoantibody profile, treatment, and outcome of cases of ATM in our local SLE population were retrospectively analyzed and compared with SLE controls. RESULTS: Ten cases of ATM were identified among 315 patients with SLE studied, giving a prevalence of 3.2%. In 5 of the patients, ATM was the initial manifestation of SLE. The cervical cord was the most common site of involvement (50%). Cerebrospinal fluid abnormalities were present in 63% of the patients, while magnetic resonance imaging (MRI) of the spinal cord revealed abnormal T2 signals in 56%. Only one patient had lupus nephritis. ATM was not associated with antiribosomal P or anti-extractable nuclear antigen (anti-ENA) antibodies. Positive dsDNA antibody was present in 40% of the ATM cases, which was significantly lower than that of patients with active SLE without spinal cord disease (75%; p = 0.04). No significant differences in the prevalence of anticardiolipin antibodies and lupus anticoagulant between the ATM and the non-ATM group were observed. Only 3 patients with ATM showed hypocomplementemia or disease activity in other organs at the time of diagnosis. All the patients with ATM received corticosteroids, while 9 were given cytotoxic agents in addition. The response to treatment was variable -- 40% of patients had complete motor and sphincter recovery and 30% had mild residual spasticity of the lower limbs. CONCLUSION: In our SLE population, ATM was not associated with antiribosomal P, anti-ENA, or antiphospholipid antibodies. Systemic complement activation was not evident in most patients during the acute phase of myelitis. Early aggressive therapy using a combination of corticosteroid and cytotoxic agents is associated with a satisfactory outcome. Further prospective study is needed to delineate the best treatment and its efficacy in the prevention of relapses.

Acute Disease↗
PubMed1998

Association of systemic lupus erythematosus with promoter polymorphisms of the mannose-binding lectin gene.

OBJECTIVE: To investigate the distribution of promoter variants of the mannose-binding lectin (MBL) gene and correlations between the promoter variants and serum MBL concentrations in Chinese patients with systemic lupus erythematosus (SLE) and in healthy Chinese controls. METHODS: We studied the serum MBL levels and codon 54 mutation in 112 Chinese patients with SLE and 110 healthy controls. Genotyping of promoter variants of the MBL gene were done by polymerase chain reaction and allele-specific oligonucleotide hybridization. RESULTS: We found significant differences in the distribution of the 2 pairs of promoter polymorphisms, H/L and Y/X, between SLE patients and controls (P=0.018 and P=0.019, respectively). Analysis of the correlation between promoter haplotypes and serum MBL levels revealed HY as the highest-producing, LY as the intermediate-producing, and LX as the lowest-producing haplotypes. The LX haplotype was present at a frequency of 0.259 in SLE patients and 0.154 in controls and was significantly associated with SLE (P=0.019, odds ratio 1.79, 95% confidence interval 1.12-2.85). CONCLUSION: The low-producing promoter polymorphism of the MBL gene is associated with SLE, and a low serum MBL level is a risk factor for SLE. Even allowing for promoter polymorphisms and structural mutations of the MBL gene, serum MBL levels in SLE patients are still lower than those in controls, suggesting a trans-factor in regulating serum MBL levels.

Adolescent↗
PubMed1998

Clinical characteristics, treatment, and outcome of adult onset Still's disease in southern Chinese.

OBJECTIVE: To study the clinical characteristics, treatment outcome, and complications of patients with adult onset Still's disease (AOSD) in our local Chinese population. METHODS: Patients with AOSD were identified among others who attended our rheumatology clinics from 1967 to 1997 and were followed. Their clinical and laboratory features at presentation, treatment, and outcome were recorded and compared with other reported series. RESULTS: Sixteen patients with AOSD were identified. Eleven (69%) were female. Nine (56%) had onset of the disease between 16 and 35 years of age. The commonest presenting features were fever (100%), arthritis (94%), rash (85%), weight loss (69%), and sore throat (63%). Fifteen patients presented with pyrexia of unknown origin and the median duration of fever before the establishment of the diagnosis was 6 weeks (range 4-75). The acute phase response was marked in all patients with gross elevation of erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and complement levels. Hyperferritinemia (> 5 times normal) was present in 90% of cases. Most patients (81%) required corticosteroid therapy and 85% of those steroid treated patients received additional disease modifying agents. The mean duration of followup of our patients was 93.3 months (range 8-362). Five (33%) had monocyclic systemic disease, 6 (40%) had polycyclic systemic disease, and 4 (27%) had frequent relapses that progressed to a chronic arthropathy. CONCLUSION: AOSD in southern Chinese tends to run a benign course, with few patients evolving into chronic inflammatory arthropathy. A significantly lower incidence of serositis, lung involvement, and enlargement of the reticuloendothelial organs was observed at presentation compared with patients of different ethnic origins.

Acute-Phase Reaction↗
PubMed1998

Hyperprolactinemia in males with systemic lupus erythematosus.

OBJECTIVE: To study prospectively the serum prolactin (PRL) concentrations among male patients with systemic lupus erythematosus (SLE) and their possible relationship to disease activity and manifestations. METHODS: Serum PRL levels were measured by radioimmunoassay in 31 male patients with SLE and 31 age matched controls. Demographic, clinical, and laboratory features of the patients were obtained. Mean PRL levels from both groups were compared, and PRL from patients with SLE was correlated with variables of disease activity, including the SLE Disease Activity Index (SLEDAI), complement level, and anti-dsDNA titer. Thirteen patients were followed serially and changes in PRL levels in relation to fluctuation in disease activity were evaluated. RESULTS: Mean PRL levels were higher in male patients with SLE than healthy controls; however, the difference did not reach statistical significance (230 vs 194 mIU/l; p = 0.06). Hyperprolactinemia was found in 4 patients (13%) and was not associated with particular clinical manifestations or autoantibodies. Considering all patients as a whole, PRL levels did not correlate with variables of disease activity and there was no difference in PRL between patients with active versus inactive disease. A subanalysis of the 4 hyperprolactinemic patients revealed a higher SLEDAI score than those with normal PRL (8.8 vs 3.7; p = 0.20); however, the difference was not statistically significant. Among the hyperprolactinemic patients, PRL levels did not correlate with SLEDAI score or anti-dsDNA titer. Prospective studies of PRL levels in 13 patients did not indicate a role of PRL in the monitoring of disease activity or predicting relapses. CONCLUSION: Hyperprolactinemia occurred in a small proportion of male patients with SLE and its significance remained unclear. Serum PRL level did not correlate with disease activity and was not a reliable marker for disease monitoring.

Adolescent↗
PubMed1997

Nocardiosis in systemic lupus erythematosus.

OBJECTIVES: This study was performed to study the clinical presentations, treatment, and outcome of six cases of nocardial infection in the systemic lupus erythematosus (SLE) population living in Hong Kong and compare these cases with those reported in the English literature. METHODS: Records of 215 SLE patients who attended our lupus and rheumatology clinics were reviewed, and cases of nocardial infection were retrieved and studied in detail. A Medline search from 1966 to 1995 was performed to identify other reported cases. The microbiology, diagnosis, and treatment strategies of nocardiosis were assessed. RESULTS: Six cases of nocardiosis were found in our lupus series, giving a prevalence of 2.8%. Another 26 cases of nocardial infection in SLE were reported in the literature. All except one were caused by Nocardia asteroides. The lung was the commonest site of involvement (81%), followed by the central nervous system (CNS) (13%). The mortality was high (35%), especially when the CNS was involved (75%). Sulphonamides were the mainstay of treatment, and adjunctive surgical procedures may be needed for suppurative complications. CONCLUSIONS: Nocardiosis has been increasingly recognized in SLE. Although still uncommon, it is an important opportunistic infection because it is curable and mortality is usually caused by delay in diagnosis and treatment. A high index of suspicion, an aggressive approach to diagnosis, and early empirical therapy are essential principles of management.

Adult↗
PubMed1997

Parvovirus B19 infection in Hong Kong.

Human parvovirus B19 is a small DNA virus that can cause a number of diseases, notably erythema infectiosum in children, and aplastic crisis in patients with chronic haemolytic disorders. With the availability of serological tests for parvovirus infection, much is known about the prevalence of this virus in the Western population. However, there have not been any data on the epidemiological pattern of parvovirus B19 infection in Hong Kong and its surrounding region. In this report we have studied the sero-prevalence of parvovirus B19 in Hong Kong in 1983 and 1993, and were able to show a low incidence of parvovirus infection in the intervening 10 years, leading to a shift in the prevalence rate of parvovirus infection in the general population. From 1991 to 1996, of 276 patients presenting with illness which might have been caused by B19, only 2.5% were positive for IgM and 19.6% for IgG anti-B19. The prevalence of IgG anti-B19 among patients with thalassaemia major requiring frequent blood transfusion in 1995 was similar to those in the same age group in the general population, substantiating the observation that B19 infection was not common in Hong Kong in recent years.

Adolescent↗
PubMed1997

Autoantibody formation after allogeneic bone marrow transplantation: correlation with the reconstitution of CD5+ B cells and occurrence of graft-versus-host disease.

Manifestations of autoimmune diseases are common in patients who have received allogeneic bone marrow transplantation (BMT). Autoantibodies have been reported in these patients but the source and clinical significance of these autoantibodies are still obscure. In the present study the kinetics of autoantibody formation and the reconstitution of CD5+ B cells was followed in 21 patients who were submitted to allogeneic BMT. Anti-nuclear, anti-smooth muscle, anti-neutrophil cytoplasmic antibodies, anti-reticulin and rheumatoid factor were found at a frequency of 25%, 17%, 24%, 22% and 10% respectively after BMT. Anti-double stranded DNA levels were mildly elevated in 15% of samples. The screening for anti-extractable nuclear antigen, anti-mitochondrial, anti-gastric parietal cell, anti-proteinase III, anti-myeloperoxidase, anti-lactoferrin antibodies was negative. The percentage and absolute count of CD5+ B cells increased with time after allogeneic BMT. Those patients with anti-nuclear or anti-smooth muscle antibodies had significantly higher CD5+ B cell counts than those without these two antibodies. Correlations of CD5+ B cell counts with other autoantibodies were negative. Acute graft-versus-host disease (GVHD) occurred in eight of the patients and chronic GVHD in four patients, but the frequency of autoantibodies had no relationship with the occurrence of acute or chronic GVHD.

Autoantibodies↗
PubMed1997

Prolactin profile in a cohort of Chinese systemic lupus erythematosus patients.

Prolactin (PRL) is an important immunoregulatory hormone secreted by the anterior pituitary gland. Hyperprolactinaemia has been implicated in the pathogenesis of systemic lupus erythematosus (SLE). However, clinical studies regarding the PRL level and lupus disease activity have yielded contradictory results. The aim of our present study was, therefore, to re-evaluate the association of PRL level and disease activity in SLE by analysing a larger patient cohort and following them up serially. Seventy-two consecutive SLE patients were recruited and the serum PRL level was measured at each visit. Our results showed that hyperprolactinaemia (> 500 mIU/l) occurred in 35% (25/72) of the patients. A total of 72% (18/25) of the hyperprolactinaemic patients had mild elevation (arbitrarily defined as 500-800 mIU/l) of the level only. No correlation could be found between the PRL level and various clinical and serological parameters of lupus disease activity. On serial follow-up of 44 patients, again no correlation between PRL and disease activity could be demonstrated. We conclude that hyperprolactinaemia occurs in some patients with SLE, but the serum level of PRL does not correlate with clinical or serological disease activity and is not a reliable marker for disease monitoring. The mechanism and pathoaetiological and clinical significance of hyperprolactinaemia in a small subset of SLE patients remain unclear and a longer follow-up is necessary.

Adolescent↗
PubMed1997

Bilateral Kienbock's disease in SLE.

Kienbock's disease, or radiologic avascular necrosis (AVN) of the carpal lunate, is an uncommon disease of young adults. The precise etiological mechanisms are uncertain although multiple mechanical, anatomical, and vascular factors are thought to be involved. A patient with systemic lupus erythematosus (SLE) who developed bilateral Kienbock's disease during the course of her illness was reported. A vasculopathy related to active vasculitis or the antiphospholipid antibodies was thought to be responsible.

Adult↗
PubMed1997

Increased rate of apoptosis and decreased expression of bcl-2 protein in peripheral blood lymphocytes from patients with active systemic lupus erythematosus.

Defective regulation of apoptosis may play a role in the development of autoimmune diseases, and the proto-oncogene bcl-2 is known to inhibit cells from undergoing apoptosis. We studied the rate of apoptosis with the expression of bcl-2 in peripheral blood lymphocytes of patients with systemic lupus erythematosus (SLE). A lower proportion of lymphocytes were bcl-2+ in SLE patients with active disease (median 84.9%) than in patients with inactive disease or normal (medians 95.3% and 97.1% respectively, p < 0.05). The rate of apoptosis of freshly isolated PBL was significantly higher in SLE patients than in normal (medians 1.2% vs 0.5%, p < 0.05). After 48-hour culture the apoptotic rate was further increased in SLE patients, particularly those with active disease (SLE overall 34.2%, active 62% inactive 27.5%, normal 11.25%). These findings support the theory that in SLE patients increased apoptosis may provide a source of extracellular nuclear antigens which stimulate the autoimmune response and form immune complexes with autoantibodies.

Apoptosis↗