A multicentre, prospective study comparing autoantibody diagnostic assays in myasthenia gravis

Laura DeGiglio

A multicentre, prospective study comparing autoantibody diagnostic assays in myasthenia gravis

Autori

LAURA DEGIGLIO (1. NEUROMUSCULAR AND RARE NEUROLOGICAL DISEASE CENTER, NEUROLOGY UNIT, SAN FILIPPO NERI HOSPITAL, ASLROMA1, ROME, ITALY – NEUROLOGIA)
LAURA CUOMO (2. CLINICAL PATHOLOGY UNIT, LABORATORY DEPARTMENT, SAN FILIPPO NERI HOSPITAL, ASLROMA1, ROME, ITALY – PATOLOGIA CLINICA)
MARINA VITILLO (2. CLINICAL PATHOLOGY UNIT, LABORATORY DEPARTMENT, SAN FILIPPO NERI HOSPITAL, ASLROMA1, ROME, ITALY – PATOLOGIA CLINICA)
FRANCESCA CORTESE (1. NEUROMUSCULAR AND RARE NEUROLOGICAL DISEASE CENTER, NEUROLOGY UNIT, SAN FILIPPO NERI HOSPITAL, ASLROMA1, ROME, ITALY – NEUROLOGIA)
MARIANNA BRIENZA (1. NEUROMUSCULAR AND RARE NEUROLOGICAL DISEASE CENTER, NEUROLOGY UNIT, SAN FILIPPO NERI HOSPITAL, ASLROMA1, ROME, ITALY – NEUROLOGIA)
STEFANIA MORINO (3. NESMOS DEPARTMENT, NEUROPHYSIOLOGICAL UNIT, SANT’ANDREA HOSPITAL, SAPIENZA UNIVERSITY, ROME, ITALY – NEUROLOGIA)
LAURA FIONDA (3. NESMOS DEPARTMENT, NEUROPHYSIOLOGICAL UNIT, SANT’ANDREA HOSPITAL, SAPIENZA UNIVERSITY, ROME, ITALY – NEUROLOGIA)
MATTEO GARIBALDI (3. NESMOS DEPARTMENT, NEUROPHYSIOLOGICAL UNIT, SANT’ANDREA HOSPITAL, SAPIENZA UNIVERSITY, ROME, ITALY – NEUROLOGIA)
GIOVANNI ANTONINI (3. NESMOS DEPARTMENT, NEUROPHYSIOLOGICAL UNIT, SANT’ANDREA HOSPITAL, SAPIENZA UNIVERSITY, ROME, ITALY – NEUROLOGIA)
FRANCESCA GRAGNANI (4. NEUROLOGICAL UNIT, SANDRO PERTINI HOSPITAL, ROME, ITALY – NEUROLOGIA)
ANTONIO PETRUCCI (5. CENTER FOR NEUROMUSCULAR AND NEUROLOGICAL RARE DISEASES, SAN CAMILLO FORLANINI HOSPITAL, ROME, ITALY – NEUROLOGIA)
CARLO PIANTADOSI (6. NEUROLOGICAL UNIT, SAN GIOVANNI HOSPITAL, ROME, ITALY – NEUROLOGIA)
MAURIZIO INGHILLERI (7. NEUROPHYSIOLOGICAL UNIT, POLICLINICO UMBERTO I, SAPIENZA UNIVERSITY, ROME, ITALY – NEUROLOGIA)
MARIA ANTONIETTA INSGRO’ (2. CLINICAL PATHOLOGY UNIT, LABORATORY DEPARTMENT, SAN FILIPPO NERI HOSPITAL, ASLROMA1, ROME, ITALY – NEUROLOGIA)
MATTEO PRATALI (8. SOD IMMUNOALLERGOLOGIA, AOU CAREGGI, FIRENZE, ITALY – PATOLOGIA CLINICA)
MARIA TOTARO (8. SOD IMMUNOALLERGOLOGIA, AOU CAREGGI, FIRENZE, ITALY – PATOLOGIA CLINICA)
ELENA MARIA PENNISI (1. NEUROMUSCULAR AND RARE NEUROLOGICAL DISEASE CENTER, NEUROLOGY UNIT, SAN FILIPPO NERI HOSPITAL, ASLROMA1, ROME, ITALY – NEUROLOGIA)

Presentatore

LAURA DEGIGLIO (NEUROMUSCULAR AND RARE NEUROLOGICAL DISEASE CENTER, NEUROLOGY UNIT, SAN FILIPPO NERI HOSPITAL, ASLROMA1, ROME, ITALY)

Modalità

Oral Communication

Abstract

“A mosaic biochip (fixed-cell based assay, F-CBA) based on detection by Indirect Immunofluorescence (IIF) of fetal (AChR-♑) and adult (AChR-♏) subunits of AChR and MuSK, transfected in human embryonic kidney cells together with the clustering protein rapsyn, has been recently commercialized for the laboratory diagnosis of myasthenia gravis. Radioimmunoprecipitation assay (RIPA) is considered the gold standard method for anti-AChR and anti-MuSK antibodies detection, but, employing radioactive isotopes, its use is very limited. Enzyme-Linked Immunosorbent Assay (ELISA) based on direct or competitive methods is largely utilized but his accuracy is discordant. Only one prospective study with these three methods on a large Chinese population has been published so far. We compared the three methods in a clinical setting on patients, recruited from 6 neuromuscular disease centers, suspected of myasthenia gravis.
Among 205 progressive samples (October 2022 and July 2023), we have selected 78 samples (48 females; mean age 62 ±16 years) with extensive clinical and neurophysiological data, to evaluate diagnostic accuracy of the three available methods in myasthenia diagnosis. Of the 78 patients, 54 had confirmed diagnosis of myasthenia (AchR+, MUSK+, doubleSeronegative).
The sensitivities, specificities and overall accuracies were calculated for RIPA, ELISA, and F-CBA: sensitivity (79.6%, 77.8%, 66.7%, respectively), specificity (75.0%, 70.8%, 83.3%, respectively), overall accuracy (78.2%, 75.6%, 71.8%, respectively).
Conclusions: We found that F-CBA has lower sensitivity but higher specificity in respect to ELISA and RIPA methods. However, studies on larger cohorts of patients are needed to better guide the use of available methods in serological diagnosis of myasthenia.”