Conundrums in nosology: synovitis, acne, pustulosis, hyperostosis, and osteitis syndrome and spondylarthritis

Chronic Recurrent Multifocal Osteomyelitis (CRMO) and Juvenile Spondyloarthritis (JSpA): To What Extent Are They Related?

Chronic recurrent multifocal osteomyelitis (CRMO) is an autoinflammatory disease occurring mainly in the pediatric age group (before 16 years) and generally presents as a separate entity. Synovitis, acne, pustulosis, hyperostosis and osteitis (SAPHO) syndrome combines osteoarticular and cutaneous involvement, similar to CRMO, and falls into the spectrum of spondyloarthritis (SpA). The fact that a patient can progress from one disease to another raises the question of whether CRMO, like SAPHO, could fall within the spectrum of SpA, ranging from a predominantly osteoarticular form to an enthesitic form with more or less marked skin involvement. In this review, we set out to discuss this hypothesis by highlighting the differences and similarities between CRMO and juvenile SpA in clinical, radiological and pathophysiological aspects. A common hypothesis could potentially consider intestinal dysbiosis as the origin of these different inflammatory diseases. Interindividual factors such as gender, environment, genetics and/or epigenetic background could act as combined disease modifiers. This is why we suggest that pathophysiology, rather than clinical phenotype, be used to reclassify these diseases.

A case of synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome with isolated lesions of the thoracic spine

We report a case of isolated lesions of the thoracic spine attributed to synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome. A 55-year-old woman who suffered from 6 months of back pain had vertebral osteomyelitis on magnetic resonance imaging (MRI). There were no laboratory findings suggestive of infection, malignancy, or autoimmune disease. Radiography, computed tomography (CT), and MRI of the thoracic spine showed mixed lesions of sclerosis and erosion, whereas bone scintigraphy did not show accumulation at any site except the thoracic spine. No lesions in the anterior chest wall or sacroiliac joints were apparent from CT and MRI. No lesions other than at the thoracic spine were observed. As the isolated lesions of the thoracic spine were considered not to have resulted from infection, malignancy, or autoimmune disease, the patient was referred to our department for differential diagnosis. Given that isolated sterile hyperostosis/osteitis among adults is included in the modified diagnostic criteria for SAPHO syndrome, we suspected that the mixed lesions of sclerosis and erosion of the thoracic spine in this case may reflect SAPHO syndrome with chronic non-bacterial osteitis (CNO) of the thoracic spine. Treatment with non-steroidal anti-inflammatory drugs (NSAIDs) was initiated and led to alleviation of her back pain, although the thoracic spine lesions remained on the 6-month MRI. Based on the CNO of the thoracic spine and the rapid response to NSAIDs, the final diagnosis was SAPHO syndrome with isolated lesions of the thoracic spine.

Pro and contra: is synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) a spondyloarthritis variant?

PURPOSE OF REVIEW

The purpose of this review is to present the up-to-date evidence on the epidemiology, pathogenesis, musculoskeletal manifestations, and imaging of the synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome and to discuss its relationship with spondyloarthritis (SpA).

RECENT FINDINGS

SAPHO is a rare inflammatory disorder of bone, joints, and skin, with a worldwide distribution that predominantly affects the middle-age adults. The hallmark of the syndrome is a constellation of sterile inflammatory osteitis, hyperostosis, and synovitis involving the anterior chest wall, associated with acneiform and neutrophilic dermatoses, such as palmoplantar pustulosis and severe acne. The axial skeleton, sacroiliac, and peripheral joints can be involved in a similar fashion to SpA. The pathogenesis of the syndrome is multifactorial. The diagnosis is mainly based on the clinical and typical radiological features. The treatment approach is based on the off-label use of antibiotics, bisphosphonates, disease-modifying antirheumatic drugs, and anticytokine biologics.

SUMMARY

The SAPHO syndrome shares common features with SpA-related diseases, yet also shows some unique pathogenetic and clinical features. The nosology of SAPHO remains a subject of controversy, awaiting further research into the pathogenetic and clinical aspects of this syndrome. A better understanding of these aspects will improve the diagnostics and clinical care of patients with SAPHO.

SAPHO Syndrome Presenting With Atlo-Epistrophic Synovitis and Left Vocal Cord Paresis: A Challenging Diagnosis

SAPHO (synovitis, acne, pustulosis, hyperostosis, and osteitis) is a rare syndrome mainly characterized by cutaneous and osteoarticular manifestations. The most typical osteoarticular manifestations are localized to the anterior chest wall and include a usually noninfectious osteitis, hyperostosis, and synovitis of the sternoclavicular joints. However, clinical presentation of SAPHO syndrome can be quite heterogeneous. Several clinical and radiological features are shared with other well-defined pathological entities, and clinical signs and symptoms often occur at different timepoints. Mainly due to this complexity and its rarity, there are currently no validated diagnostic criteria for SAPHO syndrome. Inflammation of the soft tissues around the bones and possible nerve compression could contribute to dysphagia, hypophonia, or obstruction of the airways. Neurologic manifestations could therefore be part of this multiorgan involvement. Here, we present a case of SAPHO syndrome with atypical onset symptoms, characterized by left vocal cord paralysis, acute neck pain due to osteolytic atlantoepistrophic lesion, and an unusual cutaneous manifestation, diagnosed as mid-dermal elastolysis. The latest two, to the best of our knowledge, have been here first described in a case of SAPHO syndrome.

SAPHO Syndrome and Pustulotic Arthro-Osteitis (PAO)

Synovitis, Acne, Pustulosis, Hyperostosis and Osteitis (SAPHO) syndrome is a rare inflammatory osteo-articular disorder, which encompassed many diseases, including pustulotic arthro-osteitis (PAO). Bone and joint manifestations, including osteitis, synovitis and hyperostosis, are the hallmark of the SAPHO syndrome and affect a variety of regions of the body. Recent GRAPPA survey indicated that more than 80 percent of cases of SAPHO syndrome in Japan were thought to be PAO, originally proposed by Sonozaki et al. in 1981, whereas severe acne was the most commonly reported skin ailment amongst participants with SAPHO syndrome in Israel. SAPHO syndrome is a rare disease and adequate data regarding its prevalence remains unavailable, whereas prevalence of PPP was reported to be 0.12 % in Japan and 10-30% of patients with PPP had PAO. SAPHO syndrome and PAO are predominantly found in patients in the third through fifth decades of life, and a female predominance are seen in both groups. The diagnosis of SAPHO syndrome/PAO is typically made by a rheumatologist or dermatologist. Identification of a variety of the clinical, radiological, and laboratory features outlined, as well as diagnostic criteria, are used to make the diagnosis. Goals for treating patients with SAPHO syndrome/PAO seek to maximize health-related quality of life by improving skin and articular symptoms, preventing structural changes and destruction, and normalizing physical function and social participation. Finally, we review the non-pharmacological (ie: smoking cessation and controlling focal infections) and pharmacological managements including NSAIDs, bisphosphonates, cs DMARDs, bDMARDs, and other treatments for SAPHO syndrome/PAO.

Role of the F-BAR Family Member PSTPIP2 in Autoinflammatory Diseases

Proline-serine-threonine-phosphatase-interacting protein 2 (PSTPIP2) belongs to the Fes/CIP4 homology-Bin/Amphiphysin/Rvs (F-BAR) domain family. It exhibits lipid-binding, membrane deformation, and F-actin binding activity, suggesting broader roles at the membrane–cytoskeleton interface. PSTPIP2 is known to participate in macrophage activation, neutrophil migration, cytokine production, and osteoclast differentiation. In recent years, it has been observed to play important roles in innate immune diseases and autoinflammatory diseases (AIDs). Current research indicates that the protein tyrosine phosphatase PTP-PEST, Src homology domain-containing inositol 5’-phosphatase 1 (SHIP1), and C‐terminal Src kinase (CSK) can bind to PSTPIP2 and inhibit the development of AIDs. However, the mechanisms underlying the function of PSTPIP2 have not been fully elucidated. This article reviews the research progress and mechanisms of PSTPIP2 in AIDs. PSTPIP2 also provides a new therapeutic target for the treatment of AIDs.

Chronic Nonbacterial Osteomyelitis of the Sternocostoclavicular Region in Adults: A Single-Center Dutch Cohort Study

Sternocostoclavicular hyperostosis (SCCH) is a rare autoinflammatory bone disorder caused by chronic nonbacterial osteomyelitis (CNO), which is associated with sclerosis and hyperostosis primarily affecting the sternum, the medial end of the clavicles, and the first ribs. Other areas of the axial skeleton may also be affected. The more severe synovitis–acne–pustulosis–hyperostosis–osteitis (SAPHO) syndrome is additionally associated with dermatoses and joint manifestations. This Dutch retrospective cross‐sectional single‐center cohort study characterizes the spectrum of clinical features in adult CNO/SCCH patients at the time of diagnosis. The only inclusion criteria was the availability of complete sets of clinical and imaging data systematically collected over three decades using in‐house protocols. Data from 213 predominantly female patients (88%) with a median age of 36 years at presentation were studied. The mean diagnostic delay was 5 ± 5 years. The main symptoms were chronic pain (92%), bony swelling (61%), and restricted shoulder girdle function (46%); 32% had palmoplantar pustulosis and 22% had autoimmune disease. The majority (73%) had isolated SCCH; 59 (27%) had additional localizations in vertebrae (19%), the mandible (9%), or both (2%); 4 had SAPHO. The prevalence of current or past smoking was high (58%), particularly for patients with palmoplantar pustulosis (76%). There was a significant relationship between delay in diagnosis and both the extent of affected skeletal sites (p = 0.036) and erythrocyte sedimentation rate levels (p = 0.023). Adult‐onset CNO is characterized by distinctive clinical and radiological features, but diverse aspects of its spectrum are currently not fully captured by a comprehensive classification. Delayed diagnosis is still common and potentially associated with irreversible structural changes and debilitating chronic symptoms, increasing the burden of illness and negatively impacting on quality of life. It is hoped that findings from this study will dispel confusion about nomenclature and classification of adult‐onset CNO and increase awareness of its distinctive clinical and radiological features, and thus facilitate early diagnosis and referral for treatment, which should positively impact prognosis by preventing disease progression, although this remains to be established. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Coexistence of Sjögren syndrome in patients with synovitis, acne, pustulosis, hyperostosis, and osteitis syndrome: A retrospective observational study

To identify the prevalence and clinical characteristics of Sjögren syndrome (SS) in a Chinese single-center cohort of synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome.Patients diagnosed with SS were screened out from a cohort of 164 cases of SAHPO syndrome. Information regarding the patients' gender, age at onset, clinical features, laboratory tests, bone scintigraphy, and treatment was reviewed.Five patients were screened out. The prevalence of SS in SAPHO patients was 3.05% The mean onset age of SS was 48.0 ± 12.0 years old and no apparent time order in the occurrence of SAPHO and SS was observed. Compared with the general SAPHO cohort, the 5 SS patients exhibited no significant difference in the SAPHO related clinical features or inflammatory markers, except for a higher prevalence of peripheral joints and bones involvement in bone scintigraphy. Objective evidence of dryness and positive salivary gland biopsy were found in all the patients. However, the positive rates of SSA and SSB antibody were only 20%. Anti-inflammatory treatment for SS was recorded in 3 patients (ESSDAI score: 3 in 2 patients; 12 in 1 patient) with extra-glandular manifestations, severe complications or poor response to the basic treatment.The prevalence of SS is higher in the SAPHO cohort than in the general Chinese population. Objective tests or biopsy might be more indicative than the antibody detection for SS diagnosis. Anti-inflammatory treatment should be prescribed in consideration of both the severity of SS and the demand for disease activity control of SAPHO.

Comparative analysis and differentiation between SAPHO syndrome and spondyloarthropathies using whole-spine MRI

AIM

To determine the imaging characteristics of SAPHO (synovitis, acne, pustulosis, hyperostosis, and osteitis) syndrome and seronegative spondyloarthropathies (SpAs) on whole-spine magnetic resonance imaging (WS-MRI) and evaluate the role of WS-MRI in the diagnosis and differentiation of the two diseases.

MATERIALS AND METHODS

Twenty-eight patients with SAPHO and 44 with SpAs were included. All patients were symptomatic and clinically diagnosed with SAPHO or SpAs, and all underwent WS-MRI for comparison of imaging characteristics.

RESULTS

The mean age of the SAPHO patients was 48.7 ± 12.7 years, while that of the SpA patients was 34.7 ± 12.3 years (p<0.001). WS-MRI showed that the frequency of cervical, thoracic, and lumbar spine involvement was 53.6% versus 52.3%, 75% versus 88.6%, and 60.7% versus 63.6%, respectively (p=0.70, 0.13, and 0.80). The frequency of sacroiliac joint involvement was 7.1% and 100% (p<0.001). Continuous spinal involvement accounted for 50% versus 43.2%, 60.7% versus 84.1%, and 39.3% versus 40.9% in the cervical, thoracic, and lumbar vertebrae, respectively (p=0.03). WS-MRI showed that bone marrow oedema of spinal anterior corner was observed in 50% versus 75% (p=0.03). Vertebral body and posterior attachment involvement accounted for 85.7% versus 93.2% and 14.3% versus 34.1% (p=0.3, 0.06). The frequency of bone erosion in mobile spine was 75% and 36.4%, respectively (p=0.02). The frequency of intervertebral disc, endplate, anterior thoracic wall, and paraspinal soft-tissue swelling was 42.9% versus 18.2%, 53.6% versus 22.7%, 85.7% versus 42.2%, and 50% versus 11.4% (p=0.02, 0.00).

CONCLUSIONS

Factors differentiating the two groups at WS-MRI were bone marrow oedema of the spinal anterior corner, bone erosion, and swelling of the intervertebral disc, endplate, anterior thoracic wall, and paraspinal soft-tissue.

Tripterygium wilfordii Hook F. in the treatment of synovitis, acne, pustulosis, hyperostosis, and osteitis syndrome: a clinical trial

OBJECTIVE

This study aimed to investigate the efficacy and safety of Tripterygium wilfordii Hook F. (TwHF) in the treatment of osteoarticular lesions in synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome.

METHODS

Eligible SAPHO patients were recruited to this single-center trial to receive 12-week TwHF treatment. Two dose groups (1.0-mg/kg/day group and 1.5-mg/kg/day group) were designed and patients were allocated (1:1) to these two groups. The primary endpoint was the change from baseline in Ankylosing Spondylitis Disease Activity Score on the basis of C-reactive protein level (ASDAS) at week 12.

RESULTS

All the 30 included patients completed the trial. At week 12, both dose groups showed significant change from baseline in ASDAS (1.0-mg/kg/day group: - 1.34 (1.10), p = 0.000; 1.5-mg/kg/day group: - 1.53 (1.19), p = 0.000). Similar improvement was also found in the Visual Analogue Scale in global osteoarticular pain, Bath Ankylosing Spondylitis Disease Activity Index, and other efficacy measures. The results showed a fast-acting characteristic of TwHF that the maximum efficacy was achieved within the first 2-4 weeks and maintained at a stable level for the rest of the study. No significant differences were observed between the two dose groups under the current sample size. TwHF was well tolerated that no severe adverse events or irregular menstruation were recorded, except for one patient who developed severe alanine aminotransferase elevation at the last follow-up and has stopped the TwHF treatment after the 12-week follow-up.

CONCLUSIONS

TwHF should be considered for the treatment of osteoarticular lesions in SAPHO syndrome in clinical practice because of significant efficacy, reliable safety, and high socioeconomic value.

TRIAL REGISTRATION

ChiCTR1900025912 Key points • This is the first clinical trial to evaluate Tripterygium wilfordii Hook F. (TwHF) in the treatment of synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome. • Twelve-week TwHF treatment in both dose groups designed (1.0-mg/kg/day group and 1.5-mg/kg/day group) was well tolerated and could lead to significant disease remission of SAPHO syndrome. • No significant differences were observed between the two dose groups under the current sample size. • TwHF should be considered for the treatment of osteoarticular lesions in SAPHO syndrome in clinical practice because of significant efficacy, reliable safety, and high socioeconomic value.

Current status of MR imaging of juvenile idiopathic arthritis

Juvenile idiopathic arthritis (JIA) is the most common chronic arthropathy in the pediatric population. Although the diagnosis is essentially clinical for many affected joints, MR imaging has become an important tool for the assessment of joints that are difficult to evaluate clinically, such as temporomandibular and sacroiliac joints, and for screening of inflammatory changes in the entire body by whole body MRI (WBMRI) assessment. The utilization of MR imaging is challenging in the pediatric population given the need for discrimination between pathological and physiological changes in the growing skeleton. Several multicentric multidisciplinary organizations have made major efforts over the past decades to standardize, quantify, and validate scoring systems to measure joint changes both cross-sectionally and longitudinally according to rigorous methodological standards. In this paper, we (1) discuss current trends for the diagnosis and management of JIA, (2) review challenges for detecting real pathological changes in growing joints, (3) summarize the current status of standardization of MRI protocols for data acquisition and the quantification of joint pathology in JIA by means of scoring systems, and (4) outline novel MR imaging techniques for the evaluation of anatomy and function of joints in JIA. Optimizing the role of MRI as a robust biomarker and outcome measure remains a priority of future research in this field.

The effectiveness of treatments for patients with SAPHO syndrome: a follow-up study of 24 cases from a single center and review of literature

OBJECTIVES

To evaluate the effectiveness of current treatments for SAPHO syndrome (synovitis, acne, pustulosis, hyperostosis, and osteitis) by delineating the therapeutic choices and the outcome of patients in a medical center of China and review of the literature.

METHOD

An observational study was performed on patients diagnosed as SAPHO syndrome in the Peking University First Hospital from 2009 to 2015. Clinical data including osteoarticular and cutaneous manifestations, laboratory and medical imaging findings, treatments, and outcomes were analyzed retrospectively. A literature detailing the usage of medicines and SAPHO syndrome patient responses to treatment were selected.

RESULTS

Clinical data of 24 patients were analyzed in this study. The mean age was 42.4 ± 15.5 years old at the time of diagnosis. Of a total of 17 patients that received the combination treatments of NSAIDs and DMARDs, 15 of them experienced an improvement in their symptoms. Bisphosphonates were given to 18 patients. Four patients were treated with TNF blockers, and one of them had adalimumab ineffective and then improved by add-on of DMARDs. The mean follow-up period was 2.5 years. Twenty-one patients (87.5%) had a favorable outcome and exhibited improved disease condition in the last follow-up.

CONCLUSIONS

The majority of patients with SAPHO syndrome respond well to combination therapy of NSAIDs, DMARDs, and bisphosphonates. TNF blockers are effective in a patient refractory to NSAID and DMARDs. However, in case TNF blockers are ineffective, add-on of DMARDs may be effective. Thus, the proper application of conventional DMARDs is still worth a position in the treatment of SAPHO syndrome. Key Points •NSAIDs and DMARDs and/or bisphosphonates can alleviate symptoms of the majority of patients with SAPHO syndrome. •TNF blockers are effective in patients who do not respond well to NSIADs and DMARDs. •In case TNF blockers are ineffective, add-on of conventional DMARDs may be effective.

New Insights into Adult and Paediatric Chronic Non-bacterial Osteomyelitis CNO

Purpose of Review

To describe in detail the clinical synopsis and pathophysiology of chronic non-bacterial osteomyelitis and SAPHO syndrome.

Recent Findings

Chronic non-bacterial osteomyelitis (CNO) has been identified as a disease entity for almost 50 years. This inflammatory bone disorder is characterized by osteolytic as well as hyperostotic/osteosclerotic lesions. It is chronic in nature, but it can present with episodic flairs and phases of remission, which have led to the denomination “chronic recurrent osteomyelitis”, with its severe multifocal form “chronic recurrent multifocal osteomyelitis” (CRMO). For almost three decades, an infectious aetiology had been considered, since especially Propionibacterium acnes had been isolated from bone lesions of individual patients. However, this concept has been challenged since long-term antibiotic therapy did not alter the course of disease and modern microbiological techniques (including PCR) failed to confirm bone infection as an underlying cause. Over recent years, a profound dysregulation of cytokine expression profiles has been demonstrated in innate immune cells of CNO patients. A hallmark of monocytes from CNO patients is the failure to produce immune regulatory cytokines interleukin-10 (IL-10) and IL-19, which have been linked with genetic and epigenetic alterations. Subsequently, a significant upregulation of pro-inflammatory, NLRP3 inflammasome-dependent cytokines (IL-1β and TNF-α), has been demonstrated.

Summary

The current knowledge on CNO, the underlying molecular pathophysiology, and modern imaging strategies are summarized; differential diagnoses, treatment options, outcome measures, as well as quality of life studies are discussed.

Exosomal proteome from the serum, bone marrow, and palm and toe pustular skin tissues of a single patient with SAPHO syndrome

Exosome proteomic analysis may reveal differentially abundant proteins that are of significance for clarifying the pathogenesis of SAPHO (Synovitis, Acne, Pustulosis, Hyperostosis and Osteitis) syndrome. Exosomes were isolated from the serum, bone marrow and skin tissue of the palm and toe pustular areas in a unique patient with SAPHO syndrome. The exosomes were not different from those of healthy subjects in size (114.1 ± 73.7 nm) or morphology. Label-free exosome proteomic analysis identified 198 more abundant proteins and 183 less abundant compared with those of healthy subjects. Gene ontology enrichment analysis revealed that these proteins were involved in binding with a variety of biological molecules and participated in biological processes related to autoimmunity or inflammation. A total of 243 KEGG (Kyoto Encyclopedia of Gene and Genomes) pathways were enriched, of which 43 were related to immune function. It was speculated that five differentially abundant proteins, Mitogen-activated protein kinase 1 (MAPK1/MK01), Tyrosine protein kinase (SYK), Integrin beta-3 (ITB3), Serine/threonine-protein phosphatase 2a catalytic subunit alpha isoform (PP2AA) and Serine/threonine-protein phosphatase 2a 65 kDa regulatory subunit A beta isoform (2AAB), associated with multiple KEGG pathways, forms an interaction network that may be involved in the occurrence, development and prognosis of SAPHO syndrome. SIGNIFICANCE: Exosomes of SAPHO syndrome patient were not significantly different from those of healthy subjects in size and morphology. Label-free proteomic analysis of exosomal proteins in patient with SAPHO syndrome speculated 5 proteins MAPK1, SYK, ITB3, PP2AA and 2AAB, which may be involved in the occurrence, development and prognosis of SAPHO syndrome by binding with other biological molecules. It is speculated for the first time that proteins Histone H2A type 1-J and Histone H4 were related to SAPHO syndrome. Clinic relevance. Exosome proteomics can suggest novel pathological data in patients with SAPHO.

Demographic, clinical, and scintigraphic comparison of patients affected by palmoplantar pustulosis and severe acne: a retrospective study

OBJECTIVE

Synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome encompasses heterogeneous dermatological manifestations, mainly palmoplantar pustulosis (PPP) and severe acne (SA). This study aims to explore the necessity of stratified management according to skin lesions.

METHODS

In a cohort of SAPHO patients, we compared the demographic, clinical, and scintigraphic characteristics of the SAPHO patients whose skin lesion was PPP or SA.

RESULTS

A total of 249 patients were included (227 affected by PPP and 22 affected by SA). Patients with SA were younger at onset (20, interquartile ranges (IQR) 15-30 vs. 37, IQR 30-46 years old; p < 0.001) and enrollment (35, IQR 25-38 vs. 41, IQR 33-50 years old; p = 0.001), and they had a prolonged disease duration (88.5 months, IQR 18.7-216.0 vs. 16.0, IQR 7.0-48.0 months; p < 0.001) and time needed for diagnosis (7.5, IQR 2.0-19.0 vs. 1.0, IQR 1.0-4.0 years; p < 0.001). Adjusted by age, sex, and disease duration, SA was significantly associated with more disease-modifying anti-rheumatic drug (DMARD) use (adjusted odds ratio (OR) 3.72; 95% confidence interval (CI) 1.23, 12.62; p = 0.019) and more sternoclavicular joint involvement (adjusted OR 5.91; 95% CI 1.17, 61.3; p = 0.030) in two separate Firth's logistic regression models.

CONCLUSION

SAPHO patients affected by PPP or SA as the only skin lesion may have different epidemiologic features, osteoarticular manifestations, and treatment history.Key Points• SAPHO patients with PPP or SA were heterogenous in both demographic, clinical, and imaging features.• SAPHO patients with SA were mainly male and had a significantly younger age and longer duration of symptoms before diagnosis.• SA in SAPHO patients was significantly associated with more sternoclavicular involvement and more DMARD use history.

A retrospective study of bone scintigraphy in the follow-up of patients with synovitis, acne, pustulosis, hyperostosis, and osteitis syndrome: is it useful to repeat bone scintigraphy for disease assessment?

OBJECTIVES

To investigate the value of repeated bone scintigraphy in the follow-up of patients with synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome and to characterize the changing pattern of osteoarticular lesions revealed by bone scintigraphy.

METHOD

Twenty-four patients with SAPHO syndrome who had repetitively undergone bone scintigraphy and tests of inflammatory markers (erythrocyte sedimentation rate (ESR) and/or C-reactive protein (CRP)) were included in this retrospective study. The change in accumulation number was recorded as the difference in the number of accumulation sites between consecutive bone scintigraphy. The visual analog scale (VAS) for pain and medications prescribed were also reviewed. The relationships of the change in accumulation number with medication prescribed and change in ESR or CRP were analyzed.

RESULTS

Twenty-four and 23 patients had follow-up tests of ESR and CRP, from which 30 and 28 follow-up data were obtained, containing the corresponding changes in ESR and CRP, respectively. A decrease in total accumulation number observed by bone scintigraphy was rarely observed, while decreases in ESR, CRP, and VAS were predominant. The accumulation number had significantly increased over time (follow-up with ESR: r = 0.389, p = 0.034; follow-up with CRP: r = 0.438, p = 0.020), in accordance with an "imprinting" pattern, while the inflammatory markers and VAS for pain predominantly decreased. There was no significant association between the change in accumulation number (local/total) and the change in ESR or CRP values (p > 0.05) or medications used for SAPHO (p > 0.05).

CONCLUSIONS

This retrospective cohort study of 24 SAPHO patients demonstrated an "imprinting" pattern on bone scintigraphy, without a correlation to the decrease in inflammatory markers, patient disease assessment, or treatment type. Thus, repeated bone scintigraphy did not contribute an additional clinical value for the follow-up of patients with SAPHO.Key Points• In a cohort of 24 SAPHO patients, repeated bone scintigraphy revealed a continuous increase in tracer accumulation number, indicating an "imprinting" pattern.• The change in tracer accumulation number, defined as the difference in the number of accumulation sites between consecutive bone scintigraphy measurements, was inconsistent with the change in ESR, CRP, or VAS for pain.• The medications prescribed for SAPHO did not seem to contribute to a decrease in accumulation number.• Repeated bone scintigraphy did not seem to be useful for the assessment of disease activity in patients with SAPHO.

Serum levels of proinflammatory, anti-inflammatory cytokines, and RANKL/OPG in synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome

OBJECTIVE

To measure the expression of proinflammatory, anti-inflammatory cytokines, and receptor activator NK-κB ligand (RANKL)/osteoprotegerin (OPG) in synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome, and to assess the relationship between those factors and disease activity.

METHODS

We studied 30 cases of SAPHO syndrome and 15 healthy controls. According to the Visual Analogue Scale (VAS) pain scores and Bath Ankylosing Spondylitis Activity Index (BASDAI), patients were divided into active group and stable group. The serum levels of IFN-γ, TNF-α, TGF-β1, IL-1β, IL-4, IL-6, IL-8, IL-17A, IL-22, RANKL, and OPG were determined by ELISA.

RESULTS

The active group IL-6 (2.34 ± 1.31 pg/ml), IL-8 (36.41 ± 12.93 pg/ml), and IL-17A (29.17 ± 4.01 pg/ml) levels were significantly higher than those in the stable group (p < .01) and healthy controls (p < .01). RANKL in active group (73.43 ± 57.07 pg/ml) was significantly higher than the ones in other groups (p < .0001), with increased RANKL/OPG ratio in the active group compared with other groups (p < .05). While the level of TGF-β1 in the active group was significantly lower than that in the stable and control groups (p < .0001). There was no significant difference with clinical significance were found in IFN-γ, TNF-α, IL-1β, IL-4, IL-22, and OPG.

CONCLUSION

In active SAPHO patients, there was an anomaly of proinflammatory and anti-inflammatory cytokines balance in SAPHO syndrome.

Chronic recurrent multifocal osteomyelitis: a case report

Background

Chronic recurrent multifocal osteomyelitis (CRMO), also known as chronic nonbacterial osteomyelitis, is a rare, noninfectious inflammatory disorder that causes multifocal bone lesions with swelling and pain. Lytic and sclerotic bone lesions could be found on X-ray. Short tau inversion recovery magnetic resonance imaging (STIR MRI) shows bone marrow oedema, bone expansion, lytic areas and periosteal reaction. CRMO is characterized by periodic exacerbations and remissions of unclear/unknown pathogenesis.

Case presentation

A 10 years old girl, suffering from pain in her right shoulder since the age of 9 years presented to our Department. Thanks to clinical data, laboratoristic and radiological findings and bone biopsy CRMO was diagnosed. So patient started anti-inflammatory treatment and her conditions improved.

Conclusions

In a child with bone pain should be considered also rare condition as CRMO to perform a correct diagnosis and start an adequate treatment avoiding complications such as bone damage. This condition should be suspected in a child with recurrent bone pain, modest increase of inflammatory indices, lytic or sclerotic bone lesion on X Ray. Typical CRMO localizations are metaphyses of long bones, pelvis, clavicle, vertebral column, sternum, ribs, jaw, but any bone can be involved. The most common CRMO differential diagnosis is represented by infections, malignant bone tumors, Langerhans Cells Histiocytosis (LCH).

Neutrophilic dermatoses: Kids are not just little people

Neutrophilic dermatoses are a group of inflammatory skin disorders characterized by an overactive innate immune system with dysregulation of neutrophils without underlying infectious etiology. The major representative conditions discussed are Sweet syndrome; pyoderma gangrenosum; neutrophilic eccrine hidradenitis; palmoplantar eccrine hidradenitis; subcorneal pustular dermatoses; bowel-associated dermatosis arthritis syndrome; and synovitis, acne, pustulosis, hyperostosis, and osteitis. We will also discuss other neutrophilic conditions present almost exclusively in the pediatric population, including congenital erosive and vesicular dermatosis with reticulated supple scarring and the recently described group of autoinflammatory diseases. The clinical characteristics, diagnostic approach, and treatment management in the pediatric and adult population are discussed.

Clinical heterogeneity of SAPHO syndrome: challenging diagnose and treatment

Synovitis, acne, pustulosis, hyperostosis and osteitis (SAPHO) syndrome is a rare disease which is often misdiagnosed and under-recognized, because of its peculiar and heterogeneous clinical presentation. Its main features consist of cutaneous and osteoarticular manifestations, the latter affecting more often the anterior chest wall and having typical radiologic findings. There are no validated diagnostic criteria for SAPHO and no guidelines for treatment, due mainly to its rarity; as a consequence, therapy is empirical and aimed to control pain and modifying inflammatory process. To date, the use of anti-TNF agents has been proved to be a valid alternative for patients unresponsive to conventional treatments, such as NSAIDs, corticosteroids, DMARDs and biphosphonates. The clinical heterogeneity of the disease, possibly due to differences in pathogenic mechanism of different manifestations, is challenging for both diagnosis and treatment, which should aim to control both skin and bone involvement in different clinical subsets. Here, we summarize the current status of knowledge about the SAPHO syndrome and present two cases of patients with very different disease manifestations, suggesting the need for personalized treatment.

SAPHO Syndrome: Current Developments and Approaches to Clinical Treatment

SAPHO syndrome (synovitis, acne, pustulosis, hyperostosis, and osteitis) is a rare autoimmune disease which, due to its clinical presentation and symptoms, is often misdiagnosed and unrecognized. Its main features are prominent inflammatory cutaneous and articular manifestations. Treatments with immunosuppressive drugs have been used for the management of SAPHO with variable results. To date, the use of anti-TNF-α agents has proved to be an effective alternative to conventional treatment for unresponsive or refractory SAPHO cases. TNF-α is a pro-inflammatory cytokine and pivotal regulator of other cytokines, including IL-1 β, IL-6, and IL-8, involved in inflammation, acute-phase response induction, and chemotaxis. IL-1 inhibition strategies with anakinra have shown efficacy as first and second lines of treatment. In this review, we will describe the main characteristics of biological drugs currently used for SAPHO syndrome. We also describe some of the promising therapeutic effects of ustekinumab, an antibody against the p40 subunit of IL-12 and IL-23, after failure of multiple drugs including anti-TNF-α and anakinra. We discuss the use and impact of the new anti-IL-1 antagonists involved in the IL-17 blockade, in particular for the most difficult-to-treat SAPHO cases.

Different Contributions of CDKAL1, KIF21B, and LRRK2/MUC19 Polymorphisms to SAPHO Syndrome, Rheumatoid Arthritis, Ankylosing Spondylitis, and Seronegative Spondyloarthropathy

OBJECTIVES

Synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome, rheumatoid arthritis (RA), ankylosing spondylitis (AS), and seronegative spondyloarthropathy (SPA) are autoimmune diseases of unknown etiology, which share some clinical manifestations in common. Previous family-based investigations support genetic contributions to the susceptibility of these diseases. The current study evaluated whether three previously reported AS-associated single-nucleotide polymorphisms (SNPs), rs6908425 T>C in CDKAL1, rs11584383 T>C near KIF21B, and rs11175593 C>T near LRRK2/MUC19, have any genetic overlap across multiple autoimmune diseases including SAPHO syndrome, RA, AS, and SPA.

MATERIALS AND METHODS

Genomic DNA was obtained from 71 SAPHO, 125 RA, 67 AS, and 35 SPA Han Chinese patients, as well as 104 healthy controls. SNPs were genotyped by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Genotype and allele frequencies were analyzed using chi-square test.

RESULTS

rs6908425 T>C in CDKAL1 was significantly different between SAPHO cases and healthy controls (odds ratios = 2.056, 95% confidence intervals: 1.211-3.490; p = 0.007), but no SNPs were associated with the risk of developing RA, AS, or SPA (p > 0.05). Analysis of genotype distributions showed similar results. A significant difference was only found in the genotype frequency of rs6908425 in SAPHO cases (p = 0.004); no significant differences were detected among patients with RA, AS, and SPA (p > 0.05).

CONCLUSIONS

Our results suggest that rs6908425 in CDKAL1 is associated with the risk of developing SAPHO in Han Chinese populations. People who carry the risk allele T of rs6908425 might be more prone to developing SAPHO syndrome.

A case report of severely damaged hip joint caused by SAPHO syndrome treated with 2-stage total hip arthroplasty

INTRODUCTION

Synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome is an increasingly recognized entity. The hip joint is known as a less frequently affected site in SAPHO syndrome, and there has been limited reports about hip joint diseases caused by SAPHO syndrome, and as such adequate treatment for this disease spectrum is still not fully elucidated.

CASE

We describe the case of a 52-year-old man admitted for SAPHO syndrome who went on to be diagnosed with advanced secondary hip arthritis associated with disabling right hip pain. The diagnosis of SAPHO syndrome was delayed; the patient was given a clinical diagnosis of osteomyelitis and treated with prolonged courses of antibiotics and open surgical debridement at previous tertiary health facility. The patient underwent 2-stage joint replacement surgery in our hospital. At 1 year after the surgery, he is well, with minimal right hip pain and the prosthesis is functioning well.

CONCLUSION

This case shows the safety and effectiveness of the 2-stage joint replacement in treating destructive hip disease caused by SAPHO syndrome mimicking infectious arthritis.

Synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome - A challenging diagnosis not to be missed

SAPHO syndrome manifests as chronic inflammation of bones and joints, which may or may not be accompanied by skin changes. The term SAPHO is an acronym that stands for synovitis, acne, pustulosis (usually palmoplantar), hyperostosis and osteitis. The bones most commonly affected are those in the anterior chest wall (mainly the sternum, clavicles and sternocostoclavicular joints), the vertebrae and the sacroiliac joints, but peripheral and flat bones may also be involved, especially in children. There are no validated diagnostic criteria for SAPHO, and diagnosis is based on clinical and radiological findings. One of the main challenges in diagnosis is that the clinical features may occur many years apart. Additionally, patients may not develop all manifestations. Delayed diagnosis, as a result of a lack of awareness of SAPHO, can lead to patients suffering ongoing pain and disfiguring skin manifestations. One theory is that Propionibacterium acnes (isolated from bone biopsies in many SAPHO patients) triggers an auto-immune mediated chronic inflammation in genetically predisposed individuals. Treatment involves the use of nonsteroidal anti-inflammatory drugs, intra-articular steroids, bisphosphonates and biologicals. The course of SAPHO is often prolonged but, despite the challenges in diagnosis and treatment, the long-term prognosis is good.

SAPHO: Treatment options including bisphosphonates

INTRODUCTION

Both the diagnosis and treatment of the syndrome of synovitis, acne, pustulosis, hyperostosis, osteitis (SAPHO) remain difficult. We describe a case series of 21 patients with SAPHO and their response to several pharmacological treatments.

METHODS

Clinical and biochemical data, along with medical imaging, were collected from the medical records of 21 patients, diagnosed as SAPHO during follow-up between 2005 and 2013. Symptoms and inflammatory markers were recorded twice, once at first patient presentation, and once at the end of follow-up. Synovitis, acne, pustulosis, hyperostosis, and osteitis were labeled as defining features. All treatment options were categorized according to their respective responses (full remission, partial remission, and no disease control).

RESULTS

There was a female predominance and a median age of 32 years (range: 12-54 years). Median follow-up duration was 45 months (range: 0-188 months). Total prevalence of defining features in this cohort increased for each defining feature during follow-up, except for acne. All patients reached full or partial remission at the end of follow-up. A total of 14 patients were treated with bisphosphonates. Of which 8 of them went into full or partial remission.

DISCUSSION AND CONCLUSION

In our case series, none of the patients had the full presentation of SAPHO at the first consultation. Some presented with symptoms suggestive for psoriatic arthritis. This explains why diagnosis of SAPHO can be challenging. Full remission was induced in the majority of individuals. Bisphosphonates seem to be a noteworthy treatment option. We suggest a prospective placebo-controlled clinical trial with bisphosphonates to confirm this observation.

SAPHO Syndrome: Current Developments and Approaches to Clinical Treatment

SAPHO syndrome (synovitis, acne, pustulosis, hyperostosis, and osteitis) is a rare autoimmune disease which, due to its clinical presentation and symptoms, is often misdiagnosed and unrecognized. Its main features are prominent inflammatory cutaneous and articular manifestations. Treatments with immunosuppressive drugs have been used for the management of SAPHO with variable results. To date, the use of anti-TNF-α agents has proved to be an effective alternative to conventional treatment for unresponsive or refractory SAPHO cases. TNF-α is a pro-inflammatory cytokine and pivotal regulator of other cytokines, including IL-1 β, IL-6, and IL-8, involved in inflammation, acute-phase response induction, and chemotaxis. IL-1 inhibition strategies with anakinra have shown efficacy as first and second lines of treatment. In this review, we will describe the main characteristics of biological drugs currently used for SAPHO syndrome. We also describe some of the promising therapeutic effects of ustekinumab, an antibody against the p40 subunit of IL-12 and IL-23, after failure of multiple drugs including anti-TNF-α and anakinra. We discuss the use and impact of the new anti-IL-1 antagonists involved in the IL-17 blockade, in particular for the most difficult-to-treat SAPHO cases.

Synovitis, acne, pustulosis, hyperostosis and osteitis syndrome: a single centre study of a cohort of 164 patients

OBJECTIVE

The aim was to assess the clinical, laboratory and radiological features of SAPHO syndrome.

METHODS

We recruited all patients presenting to Peking Union Medical College Hospital from 2004 to 2015 diagnosed with SAPHO syndrome. The medical data, laboratory test results and imaging were collected for all patients.

RESULTS

One hundred and sixty-four patients (111 women and 53 men) were recruited to our cohort. The mean age of the patients was 40.71 years. Nine patients had osteoarticular symptoms without skin involvement. One hundred and forty-three and 25 patients had palmoplantar pustulosis and severe acne, respectively. Psoriasis vulgaris was accompanied by palmoplantar pustulosis or severe acne in 24 patients. One hundred and sixty-four patients suffered from pain in the anterior chest wall, followed by spine (12 in the cervical region, 36 in the thoracic region and 111 in the lumbosacral region) and peripheral joint (136 patients) involvement. None of the patients had IBD. The hs-CRP level was increased in 70.8% patients. Only 2.4% were HLA-B27 positive. CT scan indicated osteolysis, sclerosis and hyperostosis in the anterior chest wall and spine in SAPHO syndrome patients. The bull-horn sign was the typical characteristic of SAPHO syndrome seen in bone scintigraphy images. One hundred and thirty-one (79.9%), 85 (51.8%), 100 (61%) and 54 (32.9%) patients took NSAIDs, CSs, DMARDs and oral bisphosphonates, respectively.

CONCLUSION

SAPHO syndrome is predominant in middle-age women, characterized by dermatological and osteoarticular manifestations with unknown aetiology. CT scan and bone scintigraphy are useful for diagnosis. There is still no standard treatment to control the disease.

SAPHO syndrome: a review

INTRODUCTION

Synovitis-acne-pustulosis-hyperostosis-osteitis (SAPHO) is an acronym for various osteoarticular and dermatological manifestations that can appear in the same patient. It is a rare syndrome, but since its awareness has increased, there have been more and more such reports in the literature.

AIMS

The objectives of this review are to summarize the current state of knowledge on pediatric and adult-onset SAPHO syndrome, and to discuss treatment strategies that should be considered.

RESULTS

The SAPHO syndrome can affect patients of any age, and its etiology is still not known. The syndrome has its cognizable radiological characteristics that are most important in making the diagnosis. There are several diagnostic criteria as well, but they need further validation. No standard treatment protocols are available and current treatment options are not evidenced-based due to the rarity of the syndrome. Therapy is empirical and aimed at easing pain and modifying the inflammatory process. It includes nonsteroidal anti-inflammatory drugs (NSAIDs) as the first-line agents. Antibiotics, corticosteroids, disease-modifying anti-rheumatic drugs, biologicals targeting tumor necrosis factor alpha or interleukin-1, and bisphosphonates have all been used with variable success. Surgery is reserved to treat complications. Even though it is a disease with good long-term prognosis, its treatment remains a challenge and the results are known to be disappointing, especially with the skin component of the disease.

CONCLUSION

It is expected that these patients present at the time of diagnosis and the treatment should be as early, effective, and safe as possible in order to prevent osteoarticular progression and to limit the adverse events associated with pharmacological drugs.

Increased neutrophil infiltration, IL-1 production and a SAPHO syndrome-like phenotype in PSTPIP2-deficient mice

OBJECTIVE

Proline-serine-threonine-phosphatase-interacting protein 2 (PSTPIP2) is involved in macrophage activation, neutrophil motility and osteoclast differentiation. However, the role of PSTPIP2 in inflammation and autoinflammatory diseases is still not clear. In this study, we generated PSTPIP2 knockout (Pstpip2(-/-)) mice to investigate its phenotype and role in autoinflammatory diseases.

METHODS

We constructed a Pstpip2-targeting vector and generated Pstpip2(-/-) mice. The phenotype and immunopathology of Pstpip2(-/-) mice were analysed.

RESULTS

All Pstpip2(-/-) mice developed paw swelling, synovitis, hyperostosis and osteitis, resembling SAPHO syndrome, an inflammatory disorder of the bone, skin and joints. Multifocal osteomyelitis was found in inflamed paws, with increased macrophage and marked neutrophil infiltrations in the bone, joint and skin. Profound osteolytic lesions with markedly decreased bone volume density developed in paws and limbs. Neutrophil-attracting chemokines and IL-1β were markedly elevated in inflamed tissues.

CONCLUSION

Our study suggests that PSTPIP2 could play a role in innate immunity and development of autoinflammatory bone disorders, and may be associated with the pathogenesis of human SAPHO syndrome.

Severe inflammation associated with synovitis, acne, pustulosis, hyperostosis, osteitis (SAPHO) syndrome was markedly ameliorated by single use of minocycline

We describe the case of a 63-year-old female who presented with severe inflammatory spondylitis, refractory to various antibiotics. Mycobacterial and fungal osteomyelitis were unlikely. Although asymptomatic, she also had osteomyelitis in the sternocostoclavicular region, and was suspected of having synovitis, acne, pustulosis, hyperostosis, osteitis (SAPHO) syndrome, against which minocycline showed marked efficacy. The presence of severe inflammatory SAPHO, albeit rare, together with the marked efficacy of tetracycline, should be noted.

Diagnosing the SAPHO syndrome: a report of three cases and review of literature

SAPHO, an acronym for synovitis, acne, pustulosis, hyperostosis and osteitis, is a heterogeneous entity with myriad presentations and features overlapping with other entities. It is a differential in patients presenting with skin and bone symptoms, either singly or in combination. Often misdiagnosed radiologically as a malignancy or infection, the diagnosis is seldom thought of. We present three cases referred to us for evaluation of findings unrelated to the presenting symptoms. After evaluation, a (99)Tc bone scan was ordered, which showed the 'bull's head sign' in all the three cases, confirming the diagnosis. We review the literature for SAPHO. It has a few features which point to its diagnosis and can help us to distinguish it from other seronegative arthritis. The clinician should be aware of this entity and should not hesitate to order a (99)Tc bone scan. We conclude that SAPHO is not rare, but rather, it is underdiagnosed. High index of suspicion is necessary for diagnosis. A (99)Tc bone scan is diagnostic and should be ordered in patients having any of the presenting features of the syndrome. We put forward the suggestion of using (99)Tc bone scintigraphy to define a 'pre-MRI' stage of ankylosing spondylitis.

Reactive arthritis: developments and challenges in diagnosis and treatment

Reactive arthritis (ReA) has traditionally been described as a nonseptic arthritis occurring in the joint following an extra-articular bacterial infection. This concept became clinically associated with antecedent infections of either the gastrointestinal or genitourinary tract. Yet this operational definition of ReA has led to diagnostic uncertainty in different clinical settings. There are several scenarios in which the ReA has been complex. One is in the SAPHO syndrome, which shares many features with ReA. Another is the development of arthritis after infection with atypical organisms such as Clostridium difficile and Giardia lamblia. Treatment of ReA remains an area of ongoing investigation. There has been a randomized controlled trial of combination antibiotics in Chlamydia-induced ReA, which reported a positive result. There are several uncontrolled reports of anti-TNF agents being used successfully in refractory ReA. These studies in treatment modalities require validation on larger samples but do provide some encouraging preliminary findings from which to develop new therapeutic approaches.

The SAPHO syndrome--are microbes involved?

The syndrome of synovitis, acne, pustulosis, hyperostosis and osteitis (SAPHO) includes a rare group of chronic, relapsing, inflammatory osteoarticular disorders that is conventionally associated with manifestations in the skin. Diagnostic dilemmas can arise due to incomplete manifestations or confusion generated through mimicking of other conditions, such as osteomyelitis. The aetiology of this syndrome remains unclear, but probably involves genetic, immunological and infectious mechanisms. The possible pathogenetic role of infectious agents in genetically predisposed individuals, resulting in a 'reactive osteitis', has been suggested because microbes such as Propionibacterium acnes have been recovered from bone biopsy samples. However, this hypothesis has not been demonstrated as yet. Current knowledge with regard to treatment of this syndrome is based on results reported from small case studies and, thus, is still empiric. The use of antibiotics, instituted based on the isolation of Propionibacterium acnes, has been reported to show conflicting results. Promising results for potential future application have recently been reported for treatment of SAPHO with bisphosphonates and antagonists of tumour necrosis factor-α. This review aims to evaluate the existing knowledge on the SAPHO syndrome and to provide information on symptoms, diagnosis and treatment options for this disease.

Long-term treatment of severe SAPHO syndrome with adalimumab: case report and a review of the literature

SAPHO (synovitis, acne, pustulosis, hyperostosis, and osteitis) syndrome defines an association of inflammatory cutaneous disorders with osteoarticular manifestations and represents a clinical and therapeutic challenge. We report a case of severe SAPHO syndrome with acne conglobata and a diffuse involvement of the anterior chest wall and sacroiliac joints that required treatment with isotretinoin and adalimumab, a new fully human anti-tumor necrosis factor (TNF)-α monoclonal antibody. Combination treatment determined a complete clinical remission of cutaneous and osteoarticular manifestations after 48 weeks. Despite maintenance of clinical remission, follow-up imaging studies after 24 months of adalimumab monotherapy revealed osteoarticular disease progression, with features of inflammatory osteitis. TNFα antagonists have been used as third-line therapy for SAPHO syndrome in single case reports or case series, but these lack consistent long-term follow-up. SAPHO syndrome can present an intermittent-favorable course in the majority of cases as well as a chronic-progressive course, the latter requiring aggressive combination treatment with TNFα antagonists and conventional systemic agents.

Clinical care of children with sterile bone inflammation

PURPOSE OF REVIEW

To review the current literature of sterile bone inflammation in childhood and to evaluate the evidence for clinical care including diagnostic methods and treatment.

RECENT FINDINGS

Chronic noninfectious osteomyelitis includes several different entities marked by sterile bone inflammation associated with histologic evidence of a predominant neutrophil infiltration in the absence of autoantibodies and autoreactive T cells, some of which are associated with a genetic mutation. Whole body MRI is helpful in detecting asymptomatic lesions. Initial treatment with NSAIDs is usually sufficient to control symptoms as the bone heals. However, if the lesions persist and do not respond to first-line treatment, or involve the spine or hip, treatment with bisphosphonate will usually lead to a resolution of symptoms. Rarely, treatment with anti-TNF agents is required.

SUMMARY

This review summarizes recent information on diagnosis, treatment and prognosis of disorders involving sterile bone inflammation in childhood. It also addresses the evolving differential diagnosis for autoinflammatory disorders that include sterile bone inflammation and presents a treatment algorithm for management.

Tumor Necrosis Factor-α Blockers in SAPHO Syndrome: Table 1

Objective.

To analyze the clinical efficacy of anti-tumor necrosis factor-α (TNF-α) therapy in treatment of synovitis, acne, pustulosis, hyperostosis, osteitis (SAPHO) syndrome, we describe cases of refractory SAPHO syndrome and review cases treated with anti-TNF-α reported in the literature.

Methods.

We describe 6 cases of patients with SAPHO syndrome treated with anti-TNF-α between 2004 and 2008. Therapeutic response was evaluated according to improvement in pain score, amelioration of disease activity, and improvement in function. The efficacy of treatment was considered to be reduced need for analgesics and/or antiinflammatory therapy.

Results.

In our series, 4 patients received infliximab, 1 etanercept, and 1 adalimumab. These treatments brought clinical response in 4 patients (66.6%): response was sustained with infliximab in 1 case for 7 months; with adalimumab in another case for 22 months; and with etanercept in 2 cases for 1 and 42 months, respectively. In contrast, 2 other patients showed no response to infliximab. Improvement was initially temporary after infusions 1 and 2, then pain recurred at Week 14. Skin lesions were healed in 3 of 4 cases, but recurred or worsened in 2 cases, after infusion 2 of infliximab. Treatment was generally well tolerated. Paradoxical psoriasis was noted in 2 cases and urticaria in 1.

Conclusion.

Given our results and those from the literature, TNF-α blockers should be considered in the therapeutic strategy of refractory cases of SAPHO syndrome, despite their effect seeming less impressive than in other spondyloarthropathies.

Genetic Susceptibility Factors in a Cohort of 38 Patients with SAPHO Syndrome: A Study of PSTPIP2, NOD2, and LPIN2 Genes

Objective.

The SAPHO syndrome (synovitis, acne, pustulosis, hyperostosis, and osteitis) is a rare disorder that mainly affects bone and skin. Chronic multifocal osteitis is the main diagnostic feature. Genetic studies of HLA genes have shown no role for these class II antigens, whereas studies of 2 mouse models (cmo and Lupo) point to a role of the PSTPIP2 gene. We analyzed the PSTPIP2 gene in patients with SAPHO syndrome.

Methods.

In a cohort of 38 patients with SAPHO we analyzed PSTPIP2 and 2 other candidate genes, NOD2/CARD15 (Crohn's disease occurs in about 10% of SAPHO patients), and LPIN2 (clinical similarities of SAPHO with Majeed syndrome).

Results.

Rare variants of the 3 genes observed in patients with SAPHO were not specific or were not found more frequently compared to controls, suggesting no major pathogenetic role of these genes in the SAPHO syndrome.

Conclusion.

We found no association between PSTPIP2, NOD2, and LPIN2 variants and the SAPHO syndrome.

Efficacy of antibiotic therapy for SAPHO syndrome is lost after its discontinuation: an interventional study

Introduction

The acronym SAPHO was introduced in 1987 to unify the various descriptions of a seronegative arthritis associated with skin manifestations and to show synovitis, acne, pustulosis, hyperostosis, and osteitis with and without sterile multifocal osteomyelitis. The etiology of SAPHO syndrome is unknown, but an association with infection by semipathogenic bacteria like Propionibacterium acnes has been suggested. We conducted an interventional study of SAPHO patients receiving antibiotics.

Methods

Thirty-seven patients met the clinical criteria of SAPHO syndrome, 21 of them underwent a needle biopsy of the osteitis lesion, and 14 of them showed positive bacteriological cultures for P. acnes. Thirty patients (14 bacteriological positive and 16 without biopsy) were treated with antibiotics for 16 weeks. The activity of skin disease and osteitis were assessed by a physician using a scoring model (from 0 to 6). In addition, patients completed a Health Assessment Score (HAS, from 0 to 6). The erythrocyte sedimentation rate was determined and a MRI (of the osteitis lesion, radiologic activity score from 0 to 2) was performed in week 1 (W1), week 16 (W16), and week 28 (W28, 12 weeks after antibiotics).

Results

Twenty-seven patients continued the medication (azithromycin, n = 25, 500 mg twice a week; clindamycin, n = 1, 300 mg daily; or doxycycline, n = 1, 100 mg daily) for 16 weeks. After W16 the scores for MRI (1.5 to 1.1, P = 0.01), skin activity (3.2 to 1.2, P = 0.01), osteitis activity (4.0 to 2.1, P = 0.02), and HAS (3.3 to 2.1, P = 0.01) decreased significantly. However, this was followed by increasing values for MRI scores (1.2 to 1.4, P = 0.08), skin activity (1.2 to 1.7, P = 0.11), osteitis activity (1.9 to 2.7, P = 0.01), and HAS (2.2 to 3.3, P = 0.02) from W16 to W28. The comparison of the scores in W1 and W28 in these 12 patients showed no significant differences.

Conclusions

For the period of application, the antibiotic therapy seems to have controlled the disease. After antibiotic discontinuation, however, disease relapse was observed. SAPHO syndrome thus groups with other chronic inflammatory arthropathies with a need for permanent therapy.

Clinical and radiologic evolution of synovitis, acne, pustulosis, hyperostosis, and osteitis syndrome: a single center study of a cohort of 71 subjects

OBJECTIVE

To assess the basic features and outcomes of synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome.

METHODS

We identified all patients seen in our unit between 1990 and 2008 diagnosed according to the proposed inclusion criteria with SAPHO syndrome, who had a followup of at least 2 years.

RESULTS

Seventy-one patients (48 women, 23 men) with SAPHO syndrome were identified. The median disease duration at the end of followup was 10 years (interquartile range [IQR] 7-15 years), and the median followup duration was 11 years (IQR 6-11.5 years). Six patients were diagnosed with Crohn's disease. Fourteen patients had never had cutaneous involvement, but 8 patients presented >1 skin manifestation. Nine patients (13%) presented a limited (<6 months) monophasic disease course, 25 cases (35%) had a relapsing-remitting course, and 37 patients (52%) had an acute painful phase with a prolonged course lasting >6 months. A total of 4% of the patients were HLA-B27 positive. Female sex (odds ratio [OR] 7.2, 95% confidence interval [95% CI] 2.2-22.9) and the presence at onset of anterior chest wall (ACW) involvement (OR 5.7, 95% CI 1.8-18.1), peripheral synovitis (P = 0.0036), skin involvement (OR 10.3, 95% CI 3.4-31.1), and high values of acute-phase reactants (OR 7.7, 95% CI 2.7-22) were correlated with a chronic disease course and involvement of new osteoarticular sites.

CONCLUSION

A chronic course is the more common evolution of SAPHO syndrome. Female sex, elevated erythrocyte sedimentation rate and C-reactive protein values, ACW involvement, peripheral synovitis, and skin involvement at the onset seem to be associated with a chronic course.