TY - JOUR
T1 - Mutations in the perforin gene can be linked to macrophage activation syndrome in patients with systemic onset juvenile idiopathic arthritis
AU - Vastert, Sebastiaan J.
AU - van Wijk, Richard
AU - D'Urbano, Leila E.
AU - de Vooght, Karen M K
AU - de Jager, Wilco
AU - Ravelli, Angelo
AU - Magni-Manzoni, Silvia
AU - Insalaco, Antonella
AU - Cortis, Elisabetta
AU - van Solinge, Wouter W.
AU - Prakken, Berent J.
AU - Wulffraat, Nico M.
AU - de Benedetti, Fabrizio
AU - Kuis, Wietse
PY - 2009/12/17
Y1 - 2009/12/17
N2 - Objective: Macrophage activation syndrome (MAS) in systemic onset juvenile idiopathic arthritis (SoJIA) is considered to be an acquired form of familial haemophagocytic lymphohistiocytosis (fHLH). FHLH is an autosomal recessive disorder, characterized by diminished NK cell function and caused by mutations in the perforin gene (PRF1) in 20-50% of patients. Interestingly, SoJIA patients display decreased levels of perforin in NK cells and diminished NK cell function as well. Here, we analysed PRF1 and its putative promoter in SoJIA patients with or without a history of MAS. Methods: DNA of 56 SoJIA patients (41 Italian and 15 Dutch) was isolated. Of these, 15 (27%) had a confirmed history of MAS. We sequenced PRF1 and 1.5 kb of the 50-upstream region. DNA sequence variations in the promoter region were functionally tested in transfection experiments using a human NK cell line. Results: We detected a previously undescribed sequence variation (-499 C > T) in the promoter of PRF1 in 18% of the SoJIA patients. However, transfection experiments did not show functional implications of this variation. Secondly, we found that 11 of 56 (20%) SoJIA patients were heterozygous for missense mutations in PRF1. In particular, we found a high prevalence of the Ala91Val mutation, a variant known to result in defective function of perforin. Interestingly, the prevalence of Ala91Val in SoJIA patients with a history of MAS (20%) was increased compared with SoJIA patients without MAS (9.8%). One SoJIA patient, heterozygous for Ala91Val, showed profound decreased perforin levels at the time of MAS. Conclusions: These findings suggest that PRF1 mutations play a role in the development of MAS in SoJIA patients.
AB - Objective: Macrophage activation syndrome (MAS) in systemic onset juvenile idiopathic arthritis (SoJIA) is considered to be an acquired form of familial haemophagocytic lymphohistiocytosis (fHLH). FHLH is an autosomal recessive disorder, characterized by diminished NK cell function and caused by mutations in the perforin gene (PRF1) in 20-50% of patients. Interestingly, SoJIA patients display decreased levels of perforin in NK cells and diminished NK cell function as well. Here, we analysed PRF1 and its putative promoter in SoJIA patients with or without a history of MAS. Methods: DNA of 56 SoJIA patients (41 Italian and 15 Dutch) was isolated. Of these, 15 (27%) had a confirmed history of MAS. We sequenced PRF1 and 1.5 kb of the 50-upstream region. DNA sequence variations in the promoter region were functionally tested in transfection experiments using a human NK cell line. Results: We detected a previously undescribed sequence variation (-499 C > T) in the promoter of PRF1 in 18% of the SoJIA patients. However, transfection experiments did not show functional implications of this variation. Secondly, we found that 11 of 56 (20%) SoJIA patients were heterozygous for missense mutations in PRF1. In particular, we found a high prevalence of the Ala91Val mutation, a variant known to result in defective function of perforin. Interestingly, the prevalence of Ala91Val in SoJIA patients with a history of MAS (20%) was increased compared with SoJIA patients without MAS (9.8%). One SoJIA patient, heterozygous for Ala91Val, showed profound decreased perforin levels at the time of MAS. Conclusions: These findings suggest that PRF1 mutations play a role in the development of MAS in SoJIA patients.
KW - Lymphocytes
KW - Macrophage activation syndrome
KW - NK cells
KW - Perforin
KW - Systemic JIA
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U2 - 10.1093/rheumatology/kep418
DO - 10.1093/rheumatology/kep418
M3 - Article
C2 - 20019066
AN - SCOPUS:77950531755
VL - 49
SP - 441
EP - 449
JO - Rheumatology
JF - Rheumatology
SN - 1462-0324
IS - 3
M1 - kep418
ER -