• Understanding the characteristics of Chronic Nonbacterial Osteomyelitis in the Irish population

    NCRC supported researchers at UCD Centre for Arthritis Research and the Department of Paediatric Rheumatology at Children’s Health Ireland have identified variable clinical presentations and treatment responses in children and adolescents with Chronic nonbacterial osteomyelitis.

    Chronic nonbacterial osteomyelitis (CNO) is an auto-inflammatory disease of childhood with an estimated prevalence of 1 case per 10e5–10e6.  It is also known as chronic recurrent multifocal osteomyelitis (CRMO). Auto-inflammatory diseases lead to recurrent episodes of inflammation with no obvious trigger. In CNO, this inflammation occurs in bones leading to localised pain, swelling, and loss of function. Although CNO associated inflammation can occur at any site, it predominantly affects the metaphyses (the section of the bone that grows during childhood) of long bones, clavicles, vertebrae, and pelvis. Long term inflammation within the bone can lead to serious complications such as unequal limb lengths or abnormal curvature of the spine (scoliosis).

    Numerous international studies have shown that CNO is a heterogenous condition, with a diverse range of clinical presentations seen across different patient cohorts. In their study, Dr Daire O’ Leary and colleagues aimed to describe the characteristics and outcomes of Irish CNO patients who attended paediatric rheumatology services at Children’s Health Ireland (Crumlin and Temple Street). The team performed a retrospective review of clinical notes, laboratory, radiology and histology results of Irish children and adolescents with CNO.

    They found that Irish children and adolescents with CNO were characterised by a low rate of unifocal disease (it was more common for patients to have bone Inflammation at multiple sites) and a low response to front line therapy with non-steroidal anti-inflammatories (medications such as Ibuprofen). Additionally, extraosseous (or non-bone) inflammatory conditions such as psoriasis (an inflammatory skin condition) and a family history of auto-inflammatory disease were extremely common in Irish CNO patients suggesting that this may represent a more inflammatory phenotype of the disease.

    On publication of the study results, Dr. Daire Leary said:

    “We know that CNO can behave differently in different people.  But it’s important to know how it behaves in the children and teenagers we’re looking after in Ireland.  It helps us to decide if research from other studies is relevant when we’re giving them information about CNO and its treatment.  This study shows that more work is needed to figure out if there are different types of this disease and if those different types need different treatments.  Comparing the children and teens who took part in this study with groups from other countries certainly suggests this”.

    This study was published in the journal “Pediatric Rheumatology”. The complete publication can be found through the following link.

    Daire O’Leary, Anthony G. Wilson, Emma-Jane MacDermott, Clodagh Lowry & Orla G. Killeen. Variability in phenotype and response to treatment in chronic nonbacterial osteomyelitis; the Irish experience of a national cohort. Pediatric Rheumatology. volume 19, Article number: 45 (2021).

    This study was funded by the NCRC, Children’s Health Foundation Crumlin, and UCD Foundation AbbVie SOBI Nordic Pharma Newman Fellowship in Rheumatology.