The Clinical Significance of Procalcitonin Elevation in Patients over 75 Years Old Admitted for COVID-19 Pneumonia

Aim. To investigate the clinical significance of procalcitonin (PCT) elevation on hospital admission for coronavirus disease-19 (COVID-19) and its association with mortality in oldest old patients (age>75 years). Methods. The clinical records of 1074 patients with chest high-resolution computed-tomography (HRCT) positive for interstitial pneumonia and symptoms compatible for COVID-19, hospitalized in medical wards during the first pandemic wave in a single academic center in Northern Italy, were retrospectively analyzed. All patients had serum PCT testing performed within six hours from admission. Information on COVID-19-related symptoms, comorbidities, drugs, autonomy in daily activities, respiratory exchanges, other routine lab tests, and outcomes were collected. Clinical characteristics were compared across different admission PCT levels and ages. The association of admission PCT with mortality was tested separately in participants aged>75 and ≤75 years old by stepwise multivariate Cox regression model with forward selection. Results. With increasing classes of PCT levels (<0.05, 0.05-0.49, 0.5-1.99, and ≥2 ng/ml), there was a significant trend (P<0.0001) towards older age, male gender, wider extension of lung involvement on HRCT, worse respiratory exchanges, and several other laboratory abnormalities. Each incremental PCT class was associated with increased risk of hospital death at multivariate models in subjects older than 75 (hazard ratio for PCT≥2 vs. <0.05 ng/ml: 30.629, 95% confidence interval 4.176-224.645, P=0.001), but not in subjects aged 75 or younger. Conclusions. In patients admitted for COVID-19, PCT elevation was associated with several clinical, radiological, and laboratory characteristics of disease severity. However, PCT elevation was strongly associated with hospital mortality only in oldest old subjects (age>75)

A comparative study on the reliability of an automated system for the evaluation of cell-based indirect immunofluorescence.

Background: Automated interpretations systems for anti-nuclear antibody (ANA), anti-double stranded DNA antibody (dsDNAab), and anti-neutrophil cytoplasmic antibody (ANCA) assessment by indirect immunofluorescence (IIF) have been recently introduced. The aim of this study was to compare the diagnostic performance of the automated IIF reading system AKLIDES with both traditional visual interpretation of IIF by laboratory experts and confirmatory tests. Methods: Visual and automated autoantibody interpretations of IIF findings using AKLIDES pattern recognition algorithms were performed for ANA on HEp-2 cells (n = 182), dsDNAab on Crithidia luciliae (n = 44) and ANCA on human neutrophils (n = 46). All serum samples tested by IIF for ANCA and dsDNAab were also assessed with the corresponding enzyme-linked immunosorbent assays (ELISAs). Out of the 182 sera tested for ANA by IIF, 116 were also assessed for antibodies to extractable nuclear antigens (ENA) by ELISA and dot immunoassay (DIA). Results: ANA testing showed an excellent agreement between visual and AKLIDES reading (98.9%). The overall agreement of dsDNAab testing on C. luciliae substrate slides was 91.0%, whereas ANCA showed a concordance of 89.1%. There was a remarkable agreement of AKLIDES findings for dsDNAab with confirmatory tests. Conclusion: Visual and automated interpretations of IIF findings for ANA, ANCA, and dsDNAab demonstrated a good agreement when assessing patients with suspected autoimmune diseases. Automated interpretation systems such AKLIDES may improve laboratory efficiency and support standardization of IIF in clinical laboratories. © 2011 Elsevier B.V.

Autoimmune uveitis in children: clinical correlation between antinuclear antibody positivity and ocular recurrences.

OBJECTIVE: The aim of this study was to identify the correlation between antinuclear antibody (ANA) titre and the onset and clinical course of uveitis in children with juvenile idiopathic arthritis (JIA) or without any other systemic autoimmune disease, i.e., idiopathic uveitis (IU). METHODS: Twenty-two patients affected by uveitis were examined. Ten had JIA-associated uveitis, 12 had IU. Follow-up ranged from 7 to 101 months. The ANA were titrated three times per year and additionally in case of ocular recurrences. All patients were treated with immunosuppressive drug combination therapy (IDCT). RESULTS: JIA-associated uveitis: ocular recurrences were noted in three ANA-positive patients and in one ANA-negative patient. IU uveitis: ocular recurrences were noted in one ANA-positive and in one ANA-negative patient. No significant rise in ANA titre was noted in either group during uveitis recurrence

Interference by heterophilic antibodies in immunoassays: wrong increase of myoglobin values.

Abstract. Aim of this work is to illustrate how analytical interference in immunoassay may produce serious errors in clinical laboratory results. The sophisticated quality assurance schemes used in many laboratories do not identify erroneous results arising from aberrant samples. Recently attention has been focused on the incidence and implication of false-positive results arising from the presence of certain substances in a patient’s serum that interfere with one or more steps in immunoassays. In this paper, we present the case of a 92 yearold woman whose plasma myoglobin concentrations falsely increased when measured using the Beckman Access assay. We demonstrated that heterophilic antibodies accounted for the falsely increased myoglobin values, and we suggest how to resolve such situations. (www.actabiomedica.it) Key words: Heterophilic antibodies, immunoassays, myoglobin values, blocking tub

Autoimmune uveitis in children: clinical correlation between antinuclear antibody positivity and ocular recurrences.

OBJECTIVE: The aim of this study was to identify the correlation between antinuclear antibody (ANA) titre and the onset and clinical course of uveitis in children with juvenile idiopathic arthritis (JIA) or without any other systemic autoimmune disease, i.e., idiopathic uveitis (IU). METHODS: Twenty-two patients affected by uveitis were examined. Ten had JIA-associated uveitis, 12 had IU. Follow-up ranged from 7 to 101 months. The ANA were titrated three times per year and additionally in case of ocular recurrences. All patients were treated with immunosuppressive drug combination therapy (IDCT). RESULTS: JIA-associated uveitis: ocular recurrences were noted in three ANA-positive patients and in one ANA-negative patient. IU uveitis: ocular recurrences were noted in one ANA-positive and in one ANA-negative patient. No significant rise in ANA titre was noted in either group during uveitis recurrence