Clinical Characteristics Of Seronegative Spondyloarthritis In Patients With Heberden Nodes

Objective: Heberden's node(HN)is widely used as a marker for diagnosis of osteoarthritis(OA).Multiple joints,but not sacroiliac joints(SIJ),have been reported to be affected by OA.In clinical practice,we have noted that the patients with HN often have heel,back and buttock pain and some of them also have positive family history of spondyloarthritis(Sp A).Furthermore,computed tomography(CT)of SIJ also shows radiographic sacroiliitis in these patients.All above are common clinical and imaging features of Sp A.However,coexistence of HN and Sp A has never been reported and often is neglected in clinical diagnosis and treatment.The aim of our study was to investigate the frequency of sacroiliitis and other features of spondyloarthritis in patients with HN and meeting the existing classification criteria for Sp A.Methods: We included 68 patients with HN who went to see a doctor in department of rheumatology at the Second Hospital of Shanxi Medical University from January 2015 to December 2016.At first,we retrospectively analyzed the medical records and diagnosis before visiting our hospital.Then,we collected a detailed medical history by using a standard questionnaire and examined routinely sacroiliac joints in each patient including CT in 68 patients with HN.Laboratory tests(including ESR,CRP,HLA-B27,RF)were ordered in all the patients.The ESSG criteria,Amor criteria and ASAS criteria were used to diagnose and classify Sp A.We also tested peripheral lymphocytes and T cell subsets of 61 HN patients and 51 healthy individuals with no symptoms of HN or spondyloarthritis as the control group.Results:Medical records before our study showed that 10 patients(14.71%)had IBP,3 patients(4.41%)had alternating buttock pain,4 patients(5.88%)had heel pain,2 patients(2.94%)had family history of Sp A.only a few patients performed lab tests before our study.3 cases(4.41%)with only ESR examination were higher than normal,4 cases(5.88%)with ESR and CRP examination were higher than normal,4 cases(5.88%)with RF examination were RF positive,and none of those 68 patients performed HLA-B27.Before our study,only 5 patients were examined by CT of SIJ and the results showed that 1 patient(1.47%)had bilateral grade 2 sacroiliitis and 4 patients(5.88%)had unilateral grade 3 sacroiliitis.According to medical records before starting our study,7 patients(10.29%)fulfilled the ESSG,Amor and ASAS criteria for the classification of Sp A,4 patients(5.88%)were diagnosed as rheumatoid arthritis(RA)and 57 patients(83.82%)were diagnosed as hand OA.After well-taken histories,lab and CT examination,most of the patients with HN diagnosed as OA showed Sp A features,especially sacroiliitis and enthesitis,with high prevalence(73.53% and 39.71%).The ESR and/or CRP were elevated in about 41.89% of these patients.We also found that 41 patients(60.29%)developed IBP,9 patients(13.24%)had alternating buttock pain,28 patients(41.18%)had family history of Sp A.In our study,because detailed medical history,lab examinations and CT of SIJ were obtained,the diagnoses of patients with HN were different.A total of 38 patients with HN(55.88%)fulfilled the ESSG,33(48.53%)Amor criteria and 50 ASAS(73.53%)criteria for the classification of Sp A.There patients(4.41%)fulfilled both Sp A criteria and the ACR 1987 revised criteria for RA.15 patients(22.06%)were diagnosis with hand OA.It is noteworthy that the absolute number and percentage of CD3+CD8+T cells were found to be significantly higher in the HN groups compared with the healthy controls.Conclusion: Most of the patients with HN showed Sp A features after our present examining but not before.Because the local pain and swelling of the hand in patients with HN are prominent,and systemic manifestations such as low back pain,heel pain and others are relatively milder,Sp A features including family history are often neglected by clinicians,not to mention further laboratory tests and CT for sacroiliac joints.Therefore,most of them were diagnosed as hand OA and some were misdiagnosed as RA,as well as only seven cases were diagnosed with Sp A.These facts suggest that HN accompanied by Sp A features should be a subtype of seronegative Sp A,which may be associated with autoimmune abnormalities.