Camptodactyly-Arthropathy-Coxa vara-Pericarditis (CACP) syndrome is a rare genetic disorder (prevalence <1/1 000 000)
characterized by early-onset camptodactyly, noninflammatory
arthropathy with synovial hyperplasia and occasionally progressive
coxa vara deformity or noninflammatory pericarditis. It is caused by
a mutation in the proteoglycan 4 (PRG 4) gene which encodes lubricin
that is the main lubricant in synovial fluid and cartilage surface.
Simultaneous autoimmune disease has never been described.
7-year old boy was admitted to Children's Clinical University
Hospital in January 2016 with a history of Juvenile idiopathic
arthritis (JIA), rheumatoid factor positive lasting for three years.
The patient has been under the doctor’s observation since the
neonatal period, he was born prematurely, had a delay of psychomotor
and language development, gait disturbances, and generalized muscle
weakness. Deformities of knee and wrist joints without pain or
morning stiffness were observed at the age of 4-year. As the
diagnosis of JIA was made, he received appropriate therapy with
NSAID, methotrexate, intra-articular glucocorticoid injections.
Despite the therapy clinical condition aggravated, he had
contractures of joints, hepatosplenomegaly, cardiomegaly, autoimmune
thyroiditis, miopathy approved histologically and in EMG. Overlap
syndrome was suspected with high ANA, ENA, anti-Ro, anti-La, Sm, RNP
antibodies. In collaboration with Hamburg Centre for Pediatric and
Adolescent Rheumatology biological therapy was initiated –
initially with TNF inhibitor Etanercept which was ineffective,
therefore was changed to Il-6 receptor inhibitor Tocilizumab. After
repeated metabolic and genetic investigations in October 2018
diagnosis of CACP was confirmed. Although biological therapy is not
effective in CACP syndrome, we observed significant clinical
improvement after initiation of Tocilizumab, therefore this therapy
is still ongoing. The CACP syndrome is very rare and commonly misdiagnosed as JIA. The efficacy of Tocilizumab may indicate that in our case there is an ongoing autoimmune process alongside.
- 3.4. Other publications in conference proceedings (including local)