Diagnostic Performance of Anti-dsDNA Tests by Indirect Immunofluorescence and Enzyme-linked Immunosorbent Assay in Patients with Systemic Lupus Erythematosus.

BACKGROUND: Several laboratory techniques for anti double-stranded (ds) DNA detection in systemic lupus erythematosus (SLE) are available, with variable diagnostic performance. We aimed to evaluate anti-dsDNA's diagnostic performance by indirect immunofluorescence (IIF) and enzyme-linked immunosorbent assay (EIA). METHODS: We conducted a single-center retrospective (2015 to 2020) study. Patients with anti-dsDNA tests by IIF and EIA were included. We evaluated the indications, applications, concordance, positive predictive value (PPV) of anti-dsDNA to confirm SLE diagnosis or flares, and associations of disease manifestations with positivity with each technique. RESULTS: A total of 1368 reports of anti-dsDNA tests by IIF and EIA and the corresponding medical records of the patients were analyzed. The main indication for anti-dsDNA testing was to help in the diagnosis of SLE in 890 (65%) of the samples, and the main application after obtaining the results was SLE exclusion in 782 (57.2%) cases. The combination with the highest frequency was the negativity result by both techniques in 801 (58.5%) cases (Cohen kappa 0.57). Both methods were positive in 300 patients with SLE (Cohen kappa 0.42). The PPVs of anti-dsDNA tests to confirm diagnosis/flare was 79.64% (95% CI, 75.35-83.35) by EIA, 78.75% (95% CI, 74.27-82.62) by IIF, and 82% (95% CI, 77.26-85.93) when both were positive. CONCLUSIONS: Anti-dsDNA detection by IIF and EIA are complementary and may indicate different clinical patterns in patients with SLE. The detection of anti-dsDNA antibodies by both techniques has a higher PPV than either separately for confirming SLE diagnosis or flares. These results highlight the need for evaluating both methods in clinical practice.

Description of the Etiologies, Clinical Characteristics, and Outcomes in Patients with Hyperferritinemia in a Colombian Tertiary Hospital.

BACKGROUND: This study analyzes the clinical characteristics, outcomes, and conditions associated with hyperferritinemia (≥5000 ng/mL) in a high-complexity center in Colombia. METHODS: This retrospective and descriptive study was performed between 2011 and 2020, at the Fundación Valle del Lili, Cali, Colombia, by reviewing medical charts from patients who had serum ferritin measurements equal to or greater than 5000 ng/mL. RESULTS: We found 350 reports of ferritin values ≥5000 ng/mL, corresponding to 317 patients, with a median ferritin value of 8789 (6001-15 373) ng/mL. The most frequent etiologies were infection (n = 198, 56.57%), hematologic disorders (n = 104, 29.71%), and blood transfusion (n = 98, 28.00%). These last 2 etiologies cooccurred in 37 (10.57%) cases. The main clinical signs accompanying hyperferritinemia were fever in 199 (56.86%) cases, multiorgan involvement in 125 (35.71%), and hepatomegaly in 95 (27.14%) cases. Ninety-four (29.65%) patients died in the hospital, and 11 (3.47%) died within 30 days after medical discharge, mainly due to infection (n = 51, 48.57%). Intrahospital mortality was associated with significantly higher ferritin levels (10 846, IQR: 6425-23 459) than survival (8452, IQR: 5980-13 932) (P = 0.018). CONCLUSIONS: Hyperferritinemia is related to many underlying causes, with infection being the principal cause in our cohort, followed by hematologic disorders. Additionally, in-hospital mortality was related to higher ferritin levels.

Reproducibility of minor salivary gland biopsy reports in Sjögren's syndrome and its correlation with disease biomarkers.

INTRODUCTION/OBJECTIVE: Sjögren's syndrome (SS) is a systemic autoimmune disease that is challenging to diagnose. Although minor salivary gland biopsy (MSGB) is a useful ancillary study, different factors make its interpretation difficult. Also, the significance of distinct histopathological findings is unknown. We aimed to determine the concordance between pathologists and rheumatologists in interpreting the MSGB results, as well as the correlation between MSGB findings, paraclinical features, and SS diagnosis. METHODS: This descriptive retrospective study reviewed medical charts from 998 individuals from a single center where MSGBs had been performed. Rheumatologists interpreted biopsy reports from pathologists, and interobserver variability was calculated. Logistic regression using immunological parameters and histological findings was performed. RESULTS: We included 998 patients with a median age of 55 years (45-64 years); the majority of patients were females (n = 934, 93.6%). Chisholm and Mason's scoring system was the most frequently used scale (55.1%). There was a good correlation between pathologists and rheumatologists for diagnosing SS using MSGB findings (Cohen's kappa 0.91). We observed a strong association between interstitial plasmocytes and SS (OR 24, 95% CI 9.09-64.94, p = 0). CONCLUSION: The MSGB is an essential tool for the diagnosis of SS. Although different factors may negatively affect its reproducibility, histological findings, such as interstitial plasmocytes, may predict the risk of developing SS. Key Points • We provide information based on 998 patients with suspected SS diagnosis. • Chisholm and Mason's scale is the most frequently used compared to Greenspan's and Tarpley's scales. • There is good correlation between pathologists and rheumatologists for the diagnosis of SS using MSGB.

Minor salivary gland biopsy: Its role in the classification and prognosis of Sjögren's syndrome.

Sjögren's syndrome (SS) is an autoimmune disorder characterized by mononuclear cell infiltration in the exocrine glands, which leads to sicca syndrome (xerostomia and xerophthalmia). The etiology of SS is unknown, but multiple environmental factors (infectious, hormonal and stress-related), as well as genetic factors, may play a role in its pathogenesis. The diagnosis of SS is complex considering its clinical and paraclinical parameters may not be very specific. The minor salivary gland biopsy (MSGB) has undoubtedly become crucial for classifying and determining the prognosis of SS. The three main different classification systems for its interpretation have been described by Chisholm and Mason, Greenspan and Daniels, and Tarpley. However, this invasive procedure has variable sensitivity and specificity as well as low reproducibility. The use of additional methods, such as skin biopsy, imaging techniques, and serum/salivary biomarkers, may be combined with current methods to develop a bioscore that could increase diagnostic performance. In this review, we summarized the main pathological findings in SS and the prognosis of patients with SS according to the biopsy results.

Therapeutic Plasma Exchange as a Treatment for Autoimmune Neurological Disease.

INTRODUCTION: Therapeutic plasma exchange (TPE) is commonly used as treatment of certain autoimmune neurological diseases (ANDs), and its main objective is the removal of pathogenic autoantibodies. Our aim was to describe the clinical profile and the experience with the usage of TPE in patients with ANDs at our institution. METHODS: This is an observational retrospective study, including medical records of patients with diagnosis of ANDs who received TPE, between 2011 and 2018. Characteristics of TPE, such as number of cycles, type of replacement solution, and adverse effects, were evaluated. The modified Rankin Scale (mRS) was applied to measure the clinical response after the therapy. RESULTS: 187 patients were included with the following diagnoses: myasthenia gravis (MG), n = 70 (37%); Guillain-Barré syndrome (GBS), n = 53 (28.3%), neuromyelitis optica spectrum disorders (NMOSD), n = 35 (18.7%); chronic inflammatory demyelinating polyneuropathy (CIDP), n = 23 (12.2%); and autoimmune encephalitis (AE), n = 6 (3.2%). The most used types of replacement solution were albumin (n = 131, 70%) and succinylated gelatin (n = 45, 24%). All patients received a median of five cycles (IQR 5-5). Hypotension and hydroelectrolytic disorders were the main complications. After TPE, 99 patients (52.9%) showed improvement in the mRS scores and a statistical significance (p < 0.05) was seen between the admission score and after TPE for every diagnosis except for CIDP. CONCLUSION: TPE has an adequate safety profile, and improvement in functionality in treated patients reflects its effectiveness.