Anti-Ro52 antibodies in clinical practice: A single-centre experience

Tropheryma whipplei infection in the lung of a patient with long COVID: a case report

BACKGROUND

Immune dysregulation in individuals with long COVID has been detected. Differential diagnosis of diffuse infiltration on chest CT in long COVID is challenging.

CASE PRESENTATION

A 62-year-old man presented with a 10-month history of dyspnea after COVID-19 infection. Dyspnea became worse in the one month preceding presentation. The chest CT showed multifocal, subpleural, bilateral opacities due to long-COVID, and infiltration around the bronchovascular bundle in the bilateral lower lung field. The pathology for the transbronchial cryobiopsy (TBCB) first reported chronic inflammation (mainly interstitial pneumonia). The patient had positive results on tests for the antibody, RO-52+, EJ+. The presumptive diagnosis of connective tissue disease-interstitial lung disease was made. Prednisone and cyclophosphamide were given. At follow-up one month later, the chest CT showed new diffuse ground-glass infiltration. The previous TBCB specimen was re-evaluated. Foamy macrophages were found in the alveolar air space. Periodic acid-Schiff (PAS) staining was performed. Numerous intracytoplasmic organisms were detected, with morphologic features consistent with those of Tropheryma whipplei. The patient recovered after intravenous ceftriaxone and oral trimethoprim-sulfamethoxazole. The final diagnosis was lung T. whipplei infection and long COVID-19.

CONCLUSION

This is the first case report of Tropheryma whipplei infection in the lung of a patient with long COVID-19. T. whipplei should be considered as a potential pathogen for diffuse lung infiltration in the post-COVID-19 era.

Ro52/TRIM21 - From host defense to autoimmunity

Ro52 (TRIM21) belongs to the ubiquitin ligase family. This protein plays a crucial role in many immunological processes, including antibody-dependent intracellular neutralization, synergy with the complement system, antiviral response, death mediation, oxidative stress response, and protein ubiquitination. Abnormal expression of TRIM21 can break immunological tolerance and lead to the production of autoantibodies against TRIM21. Antibodies against TRIM21 are detected in various autoimmune diseases, including Sjögren's syndrome (SS), systemic lupus erythematosus (SLE), or myositis. However, anti-TRIM21 presence is not limited to autoimmune connective tissue disorders. It was observed in patients with malignancies, various cancerous processes, infectious diseases, and idiopathic interstitial pneumonia. The occurrence of TRIM21 autoantibodies is also associated with clinical features, such as the prevalence of interstitial lung diseases and cardiac or haematological involvement in connective tissue disorders. The purpose of this review was to summarize current knowledge of the immunological functions of TRIM21 and analyze the clinical implications of anti-TRIM21 antibodies in the disease course.

Clinical significance of anti-rheumatoid arthritis 33 antibody in patients with systemic lupus erythematosus

Although anti-rheumatoid arthritis (RA) 33 antibodies have been reported to be present in various connective tissue diseases (CTDs), the clinical significance of anti-RA33 in CTDs is still obscure. This study was performed to explore the clinical significance of anti-RA33 in CTDs, especially systemic lupus erythematosus (SLE). A total of 565 patients with positive anti-nuclear antibodies who had been tested for anti-RA33 were included in this study and were further classified into RA33-positive and RA33-negative groups. The association between anti-RA33 and the clinical features of CTDs was examined. Receiver operating characteristic (ROC) analysis was performed to explore the diagnostic value of anti-RA33 in SLE and SLE-related organ involvement. The results showed that SLE was the most common disease in CTD patients positive for anti-RA33 (48.8%). Compared with the RA33-negative group, higher proportions of SLE-associated antibodies and SLE patients with a high disease activity as well as lower levels of serum complement components were observed in the RA33-positive group (all p < 0.05). Furthermore, CTD patients with positive anti-RA33 were more likely to suffer from mucocutaneous and hematological involvement as well as interstitial lung disease (all p < 0.05). ROC analysis revealed an area under the curve value of 0.634 (95% confidence interval: 0.587-0.681) for anti-RA33 in the diagnosis of SLE, with a specificity and sensitivity of 92.9% and 13.5%, respectively. Taken together, this study reveals a significant association between anti-RA33 and the clinical features of CTDs, especially SLE, indicating a potential clinical significance of anti-RA33 in the management of SLE.

Clinical Significance of Different Profiles of anti-Ro Antibodies in Connective Tissue Diseases

Objective

Anti-Ro60 and anti-Ro52 antibodies are associated with different connective tissue diseases (CTDs). However, the clinical significance of anti-Ro antibodies is not always consistent among different global regions. The aim of this study was to investigate the clinical characteristics of patients with anti-Ro antibodies.

Methods

A total of 1596 inpatients with anti-Ro antibodies were included in the study. Demographic, clinical, and serological data were compared between individuals with different profiles of anti-Ro antibodies: patients with anti-Ro52 antibodies alone, patients with anti-Ro60 antibodies alone, and patients with combined anti-Ro52 and anti-Ro60 antibodies.

Results

Of the 1596 patients, 1362 (85.3%) were female, the mean age was 45.5 years, and systemic lupus erythematosus (SLE) (46.0%) and Sjogren's syndrome (SS) (19.0%) were the most common CTD diagnoses. Among the patients with anti-Ro52 antibodies alone, idiopathic inflammatory myopathy (18.8%) and SLE (17.6%) were the most common CTD diagnoses. The coexistent autoantibodies of this group were significantly lower compared with those of the other two groups, while the presence of anti-Jo1 antibodies were significantly higher compared with those of the other two groups (3.7% vs. 0.6% vs. 1.9%, p = 0.029). In addition, the patients with isolated anti-Ro52 antibodies were more likely to suffer from interstitial lung disease (35.5% vs. 11.3% vs. 13.7%, p < 10^-4) and pulmonary arterial hypertension (10.1% vs. 5.3% vs. 3.6%, p = 0.001) compared with the other two groups of patients. Compared with patients with isolated anti-Ro52 or anti-Ro60 antibodies, the patients with combined anti-Ro52 and anti-Ro60 antibodies were more likely to suffer from xerophthalmia and xerostomia. Furthermore, hypocomplementemia, hyperglobulinemia, and proteinuria were particularly prevalent in patients with anti-Ro60 antibodies.

Conclusion

Different profiles of anti-Ro antibodies were significantly associated with clinical phenotypic features in CTDs, indicating the potential diagnostic and prognostic value of these antibodies in clinical practice.

Visual Evoked Potentials as Potential Biomarkers of Visual Function in Patients with Primary Sjögren's Syndrome

Visual evoked potentials (VEP) are changes in potentials that arise in the central nervous system. In the interpretation of the VEP test results, it is assumed that the elongation of the latency time is caused by the demyelination of the nerve fibers, and the axon damage is responsible for the decrease in the amplitude. The observed VEP deviations are not specific for specific diseases, but indicate disturbances in visual conductivity. VEP may play a diagnostic role in the early detection of visual involvement. The aim of the study was the functioning of visual pathway assessment on the basis of visual evoked potentials (VEP) examination, in patients with primary Sjögren’s Syndrome (pSS), without focal symptoms of central nervous system disorder. The effect of disease activity, as assessed by clinical parameters and antibody levels (anti-Ro52, SSA, and SSB), on the central nervous system was also evaluated. Thirty-two consecutive patient with pSS (31 females, 1 male) were included in the study. VEP was performed at baseline, and after 6 (T6) years. Their results were compared longitudinally between the baseline and T6, depending on the duration of the disease and treatment. The immunological activity of pSS was also analyzed. The group of patients showed a significant prolongation of the P100 implicit time (105.5 ± 5.1 vs. 100.6 ± 3.9; p = 0.000) and a significant higher the P100-N145 amplitude (12.3 ± 4.1 vs. 9.4 ± 3.0; p = 0.000). Abnormalities in electrophysiological parameters of VEP at baseline correlated with presentation of anti-Ro52 antibodies and aching joints. At baseline, the P100 implicit time was shorter for the patients with pSS than for those at T6 (105.50 ± 5.1 vs. 109.37 ± 5.67; p = 0.002). pSS patients without CNS involvement presented with dysfunction of visual pathway, as revealed by VEP abnormalities. Relationships were found between VEP parameters and with present of anti-Ro52 antibodies and aching joints. VEP may be a useful method for assessment and monitoring of subclinical visual deficit in the course of pSS.