An unusual presentation of purine nucleoside phosphorylase deficiency mimicking systemic juvenile idiopathic arthritis complicated by macrophage activation syndrome

Pediatric Rheumatology

Manuela Pardeo¹  Ivan Caiello¹  Claudia Bracaglia¹  Emiliano Marasco¹  Fabrizio De Benedetti¹  Gian Marco Moneta¹  Giusi Prencipe¹  Giulia Marucci¹  Antonella Insalaco¹  Alessia Arduini² 

[1] 0000 0001 0727 6809, grid.414125.7, Division of Rheumatology, IRCCS Ospedale Pediatrico Bambino Gesù, Piazza S. Onofrio 4, 00165, Rome, Italy;grid.7841.a, Pediatric Department, La Sapienza University of Rome, Rome, Italy;

关键词: Macrophage activation syndrome;    Juvenile idiopathic arthritis;    Interferons;    Interleukins;    Chemokines;   

DOI  :  10.1186/s12969-019-0328-3

来源: publisher

【 摘 要 】

BackgroundSystemic juvenile idiopathic arthritis (sJIA) is an inflammatory condition that presents with fever, rash and arthritis. At onset systemic features are predominant and the diagnosis may be a challenge. Secondary hemophagocytic lymphohistiocytosis (sHLH) forms may be associated with different disorders, including rheumatic diseases, and this form is called macrophage activation syndrome (MAS). CXCL9 levels, a chemokine induced by IFNγ, are significantly elevated in patients with sHLH or MAS and are correlated with laboratory features of disease activity. High levels of IL-18 have been reported in patients with MAS during sJIA, as well as in some patients with sHLH and IL-18 is indeed known to induce IFNγ production.FindingsWe report a patient with a clinical presentation highly suggestive for systemic juvenile idiopathic arthritis (sJIA) onset complicated by MAS, and was later diagnosed with purine nucleoside phosphorylase (PNP)-deficiency with HLH. Some unusual features appeared when HLH was controlled and further investigations provided the correct diagnosis. Serum CXCL9 and IL-18 levels were found markedly elevated at disease onset, during the active phase of MAS and decreased progressively during the course.ConclusionThe reported case underlines the potential difficulties in discriminating sJIA from other causes of systemic inflammation. Furthermore, this supports the notion that especially in young children with a sJIA-like disease other mimicking conditions should be actively sought for. CXCL9 and IL-18 levels suggested that patients with PNP-deficiency may have a subclinical activation of the IFNγ pathway and indeed they are predisposed to develop sHLH.

【 授权许可】

CC BY