Background: IgG4-related disease (IgG4-RD) is a systemic fibro-inflammatory disease that can affect almost any organ throughout its course. However, its longitudinal outcomes in the Southern Chinese population remain poorly characterized. Methods: We conducted a retrospective cohort study of consecutive IgG4-RD patients from November 2018 to October 2023 at a tertiary rheumatology unit in Hong Kong. Clinical characteristics, treatment patterns and outcomes, as well as factors associated with deep organ involvement were evaluated. Results: A total of 43 IgG4-RD patients (63% male, median age at diagnosis [Formula: see text] 68) with a median follow-up duration of 3.7 years were included. Multiorgan involvement (77%) and head-and-neck-limited disease (65%) were common. Multiorgan involvement was associated with a longer diagnostic delay ([Formula: see text] [Formula: see text] 0.339, [Formula: see text] [Formula: see text] 0.032). Deep organ involvement (37%) was associated with higher median baseline neutrophil counts (5.0 vs. [Formula: see text]/L, [Formula: see text] [Formula: see text] 0.049) and a greater number of affected organs (3 vs. 2, [Formula: see text] [Formula: see text] 0.003), requiring higher induction prednisolone doses and more frequent use of steroid-sparing agents. Glucocorticoid therapy led to a clinical response in all treated patients (72%), but relapse occurred in 29% of them after a median follow-up of 61 weeks. Conclusion: In this Southern Chinese cohort, IgG4-RD frequently involved deep and multiple organs. Early recognition may help prevent the development of multisystem disease. Further studies are warranted to identify optimal management strategies for IgG4-RD in this population.

Objective: To determine the association of anti-Ro antibody with the clinical features and serology in systemic lupus erythematosus (SLE) patients. Methods: This retrospective observational study enrolled 158 SLE patients at the Rheumatology Department, Fauji Foundation Hospital, from May 1 to October 31, 2023. Demographic and clinical data were collected. Patients were stratified by anti-Ro (positive vs. negative), concomitant anti-La (anti-Ro[Formula: see text]/anti-La[Formula: see text], anti-Ro[Formula: see text]/anti-La[Formula: see text], anti-Ro[Formula: see text]/anti-La[Formula: see text], and anti-Ro[Formula: see text]/anti-La[Formula: see text]), and anti-nuclear antibody (ANA) status (positive vs. negative). Mann-Whitney U and Chi-square tests were employed for comparisons, with statistical significance set at p<0.05. Results: The study population consisted mainly of females (98.7%), with a median age of 30 years. Anti-Ro[Formula: see text] patients (46.8%) exhibited higher discoid rash (16.2% vs. 6%, p [Formula: see text] 0.04), sicca symptoms (52.7% vs. 31%, p [Formula: see text] 0.005), and anemia (71.6% vs. 56%, p [Formula: see text] 0.04). No significant differences were observed in nephritis (29.7% vs. 34.5%, p [Formula: see text] 0.52) or neurological disease (9.5% vs. 11.9%, p [Formula: see text] 0.69) between the two groups. The anti-Ro[Formula: see text]/anti-La[Formula: see text] group had higher myositis (20.6%), sicca symptoms (55.9%), and fever (70.6%) compared to other groups. The ANA[Formula: see text]/anti-Ro[Formula: see text] group (48.6%) had significant association with sicca symptoms (50.7%) and fever (64.2%). Conclusion: Anti-Ro[Formula: see text] SLE in South Asians is associated with sicca symptoms, anemia, fever, and myositis—findings critical for tailored management. Co-positivity with anti-La amplifies risks, warranting vigilant monitoring.

Objective: Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by persistent joint inflammation and immune dysregulation. Aberrant activation of immune cells plays a central role in RA development and progression. This study aimed to investigate the causal relationships between specific immune cell phenotypes and RA using a bidirectional Mendelian randomization (MR) approach. Methods: We conducted two-sample bidirectional MR analyses using genome-wide association study (GWAS) summary statistics. Genetic variants significantly associated with immune cell traits ([Formula: see text] < 1 × 10[Formula: see text]) were used as instruments for forward MR, while variants associated with RA were selected using a more stringent threshold ([Formula: see text] < 5 × 10[Formula: see text]) for reverse MR in order to enhance the specificity and reliability of causal inference, particularly given the complex genetic architecture of RA. Inverse variance weighted (IVW) analysis served as the primary method, supported by weighted median and MR-Egger regression. Heterogeneity and pleiotropy were assessed using Cochran’s [Formula: see text] test and the MR-Egger intercept. Results: Forward MR identified significant causal associations between RA risk and seven immune traits, including CD4[Formula: see text] T cell memory, CD8[Formula: see text] T cell subsets, dendritic cell (DC) subpopulations, and CD4n:%pre-Th17 cells. In the reverse MR analysis, RA was found to causally affect two immune phenotypes: CD4n:%pre-Th17 and CD123[Formula: see text] on CD11c[Formula: see text] DCs. Conclusions: This study provides genetic evidence supporting a causal interplay between specific immune cell populations and RA. In particular, Th17 precursors and CD123[Formula: see text] DCs emerged as key players in both RA onset and immune remodeling.

IgG4-related disease (IgG4-RD) is a rare, multisystem, fibroinflammatory disorder with characteristic histopathology. Ongoing research continues to define optimal disease evaluation and management. We report our experience with IgG4 sialadenitis and the effectiveness of serial salivary gland ultrasound to monitor this insidious disease course and response to treatment. Specifically, we note the improvement in abnormal gland echotexture and inflammation in response to rituximab therapy. Such findings may have future applications for international classification criteria and/or treatment response.

We reported a 64-year-old woman with anti-synthetase antibodies associated with rapidly progressive interstitial lung disease (RP-ILD) presented with respiratory failure. The disease remained active despite two courses of pulse steroid and intravenous cyclophosphamide. She was subsequently treated with tofacitinib with dramatic clinical improvement. Our case demonstrated blockage of JAK1 and JAK3 could be an effective treatment in the initial phase of RP-ILD.

Schnitzler syndrome is a rare adult-onset autoinflammatory disease characterised by urticarial rash, monoclonal gammopathy, and systemic inflammation. We present the first reported case in Hong Kong, involving a 37-year-old female with a prolonged diagnostic journey of nearly a decade after initially presenting with pyrexia of unknown origin. Extensive investigations ruled out other causes, and the diagnosis was made using the Strasbourg diagnostic criteria for Schnitzler syndrome. Treatment with canakinumab, an interleukin (IL)-1[Formula: see text]inhibitor, resulted in rapid resolution of symptoms. This case highlights the importance of early recognition and timely diagnosis to improve patient outcomes in this rare condition.

Studies from Asian and European countries have demonstrated a low risk of hepatitis B virus (HBV) reactivation in patients with past hepatitis B infection (HBsAg −ve, anti-HBc [Formula: see text]ve) and rheumatic diseases receiving biological and targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs). However, data regarding Chinese patients in Hong Kong is not available. Objective: The current study was performed to report the risk of HBV reactivation in Chinese patients with past hepatitis B infection and rheumatic diseases receiving b/tsDMARDs. Method: Clinical records of patients with various rheumatic diseases receiving b/tsDMARDs between 2004 and 2018 in two public hospitals in Hong Kong were retrieved. Patients with past hepatitis B infection (HBsAg −ve, anti-HBc [Formula: see text]ve) were included for analysis. Those with baseline detectable HBV DNA were excluded. HBV reactivation was defined as either the occurrence of HBV DNA from a baseline undetectable level or reverse HBsAg seroconversion. The incidence of HBV reactivation was reported, and risk factors for HBV reactivation were studied using Cox regression. Results: A total of 180 patients with rheumatic diseases, including rheumatoid arthritis (63.3%), spondyloarthritis (30%), and systemic lupus erythematosus (3.9%), were studied. Nine patients (5%) developed HBV reactivation during a median follow-up of 14.5 months (incidence 2.76 per 100 person-years). Twenty-six (14.4%) patients were put on preemptive antiviral treatment at baseline, and none developed reactivation. Among those who had an increase in HBV DNA titers, none developed overt hepatitis or liver failure. HBV-DNA titers returned to undetectable levels after antiviral treatment in four patients (44.4%) and did not further increase in the remaining five patients (55.6%) who did not receive antiviral treatment. Conclusion: The risk of HBV reactivation was low (5%) among Chinese patients in Hong Kong with past hepatitis B infection and receiving b/tsDMARDs for various rheumatic diseases. None of the HBV reactivation cases resulted in clinical hepatitis, and HBV DNA titers dropped with antiviral therapy.

Introduction: Takotsubo Cardiomyopathy (TCM), also known as stress-induced cardiomyopathy, is an acute heart condition that mimics acute coronary syndrome and usually affects postmenopausal women. In young patients with autoimmune disorders like Systemic Lupus Erythematosus (SLE), it is uncommon and difficult to diagnose. This case report emphasizes emotional stress and autoimmune flare as co-triggers of TCM and contributes to the limited literature on such presentations. Case report: A 27-year-old woman with SLE presented with acute chest discomfort, palpitations, and shortness of breath after her father’s sudden death. She also mentioned weariness, joint discomfort, and anxiety, all of which are typical of a lupus flare. Electrocardiography revealed sinus tachycardia as well as ST-segment increases in the anterior leads. Troponin I and NT-proBNP levels were found to be increased. Coronary angiography revealed normal coronary arteries, while echocardiography revealed apical ballooning of the left ventricle, confirming the diagnosis of TCM. The patient was given intravenous methylprednisolone for lupus flare management, as well as metoprolol, intravenous fluids, hydroxychloroquine, and lisinopril after stabilization. Emotional support and education on stress management were also provided. The patient’s cardiac function and lupus activity improved significantly. She was discharged in stable condition after six days and remained asymptomatic three months later, with no return of cardiovascular symptoms and complete echocardiographic resolution. Conclusion: This case reinforces the importance of evaluating TCM in young SLE patients with acute chest pain, particularly when emotional stress is involved. Excluding coronary artery disease is essential, and effective management requires a multidisciplinary approach that treats both cardiac and autoimmune components. Preventing recurrence demands integrating emotional and psychological support into the care of chronically ill individuals.

Background: IgG4-related disease (IgG4-RD) is a rare, systemic condition characterized by inflammation and fibrosis in various organs, often presenting with elevated serum IgG4 levels, tissue infiltration by IgG4-positive plasma cells, and fibrotic changes in the affected organs. It commonly affects the pancreas, bile ducts, salivary glands, kidneys, and lymph nodes, sometimes involving unusual or less-recognized sites. IgG4-RD is an exclusion diagnosis, as it can mimic other diseases, such as infections, malignancies, and other autoimmune conditions. Treatment primarily involves corticosteroids, with a good response in many cases. However, relapses are common, and other immunosuppressive agents may be considered for refractory cases. Case report: A 41-year-old male with well-controlled HIV presented with a 3-month history of a painful, ulcerative anorectal mass that failed to resolve with antibiotics. Despite initial suspicion of an infectious etiology, biopsy results showed tissue necrosis and chronic inflammation without evidence of malignancy. Further investigation revealed elevated IgG4 levels (1,929 mg/dL) and a high IgG4/IgG ratio, leading to the diagnosis of IgG4-RD. The patient underwent surgical interventions, including debridement and colostomy, to manage complications such as acute urinary retention and extensive necrotic tissue. Treatment with corticosteroids resulted in significant clinical improvement. However, the patient experienced worsening of lesions after tapering the corticosteroids. Therefore, methotrexate was initiated as a steroid-sparing agent. Following the initiation of methotrexate, there was a notable progression of the lesions, with increased necrotic tissue and evidence of hepatitis. A positive polymerase chain reaction (PCR) for HSV-2 indicated a co-infection, which was treated with acyclovir. Following the side effect of methotrexate, rituximab (1,000 mg IV) was administered, resulting in marked improvement in lesion size and resolution of the new mass. Conclusion: This case highlights the diagnostic challenges of IgG4-RD in atypical presentations and the effectiveness of rituximab in treating refractory cases after corticosteroids and methotrexate failure.

Background: The contribution of previous foot or ankle trauma to the development of static foot deformities such as flatfoot (pes planus, PP) and cavus foot (pes cavus, PC) remains insufficiently studied. This study aimed to compare the prevalence of trauma history between these two deformity types and to assess its potential clinical associations. Methods: A retrospective comparative study was conducted using electronic medical records of patients with flatfoot or cavus foot. Data included demographics, history of foot trauma, estimated delay to consultation, pain intensity (VAS), and pain location. Statistical analysis used Chi-square and Student’s t-tests, with odds ratios (OR) and 95% confidence intervals (CI). Results: A total of 54 patients were included, comprising 44 with flatfoot and 10 with cavus foot. The mean age was 53.1 years, with a female predominance (sex ratio F/M[Formula: see text] 6.7). A history of foot trauma was reported by 11.4% of PP patients (n[Formula: see text] 5) and 10.0% of PC patients (n[Formula: see text] 1). The estimated mean interval between trauma and presentation was 14 months (SD[Formula: see text]9) for flatfoot and 16 months (SD[Formula: see text]10) for cavus foot. Most trauma cases were related to ankle sprains. Pain was present in all trauma-positive PC patients and in 80% of trauma-positive PP patients. Mean VAS pain scores were slightly higher in trauma-positive patients (5.8 ± 1.0) compared to trauma-negative ones (5.3 ± 1.1), though not statistically significant. Hindfoot pain predominated in trauma-positive PP patients (60%), whereas the single trauma-positive PC case reported both hindfoot and ankle pain. The odds of having a trauma history were similar between groups (OR [Formula: see text]1.15, 95% CI: 0.12-11.13; p > 0.05). Conclusion: In this study, Trauma history was rare and similarly distributed in flatfoot and cavus foot. No significant association was found with deformity type, although trauma-positive patients tended to report higher pain levels.