Easy recognition and high autoimmune hepatitis specificity of smooth muscle antibodies giving an actin microfilament immunofluorescent pattern on embryonal vascular smooth muscle cells.
Clin Exp Immunol
; 217(3): 233-239, 2024 Aug 09.
Article
em En
| MEDLINE
| ID: mdl-38902849
ABSTRACT
Smooth muscle antibodies (SMA) with anti-microfilament actin (MF-SMA) specificity are regarded as highly specific markers of type 1 autoimmune hepatitis (AIH-1) but their recognition relying on immunofluorescence of vessel, glomeruli, and tubules (SMA-VGT pattern) in rodent kidney tissue, is restricted by operator-dependent interpretation. A gold standard method for their identification is not available. We assessed and compared the diagnostic accuracy for AIH-1 of an embryonal aorta vascular smooth muscle (VSM) cell line-based assay with those of the rodent tissue-based assay for the detection of MF-SMA pattern in AIH-1 patients and controls. Sera from 138 AIH-1 patients and 295 controls (105 primary biliary cholangitis, 40 primary sclerosing cholangitis, 50 chronic viral hepatitis, 20 alcohol-related liver disease, 40 steatotic liver disease, and 40 healthy controls) were assayed for MF-SMA and SMA-VGT using VSM-based and rodent tissue-based assays, respectively. MF-SMA and SMA-VGT were found in 96 (70%) and 87 (63%) AIH-1 patients, and 2 controls (Pâ
<â
0.0001). Compared with SMA-VGT, MF-SMA showed similar specificity (99%), higher sensitivity (70% vs 63%, Pâ
=â
ns) and likelihood ratio for a positive test (70 vs 65). Nine (7%) AIH-1 patients were MF-SMA positive despite being SMA-VGT negative. Overall agreement between SMA-VGT and MF-SMA was 87% (kappa coefficient 0.870, [0.789-0.952]). MF-SMA were associated with higher serum γ-globulin [26 (12-55) vs 20 g/l (13-34), Pâ
<â
0.005] and immunoglobulin G (IgG) levels [3155 (1296-7344) vs 2050 mg/dl (1377-3357), Pâ
<â
0.002]. The easily recognizable IFL MF-SMA pattern on VSM cells strongly correlated with SMA-VGT and has an equally high specificity for AIH-1. Confirmation of these results in other laboratories would support the clinical application of the VSM cell-based assay for reliable detection of AIH-specific SMA.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Autoanticorpos
/
Actinas
/
Hepatite Autoimune
/
Músculo Liso Vascular
Limite:
Adolescent
/
Adult
/
Aged
/
Animals
/
Female
/
Humans
/
Male
/
Middle aged
Idioma:
En
Revista:
Clin Exp Immunol
Ano de publicação:
2024
Tipo de documento:
Article