Novel pathogenic variants in SLCO2A1 causing autosomal dominant primary hypertrophic osteoarthropathy.

Primary hypertrophic osteoarthropathy (PHO), or pachydermoperiostosis, is characterized by a clinical association including digital clubbing, periostosis and pachydermia. SLCO2A1 and HPGD genes are both responsible for PHO. The pathology is classically defined as an autosomal recessive disorder with clinical variability ranging from a mild to more severe phenotype. However, the hypothesis for an autosomal dominant form suggested for a long time was only demonstrated for the first time in 2021 for SLCO2A1. We aimed to detect a second pathogenic variant by a deep sequencing of the entire SLCO2A1 and HPGD genes, associated with functional transcription analysis in PHO patients harboring only one heterozygous variant. Among 10 PHO patients, 4 presented a single pathogenic or probably pathogenic novel variant in SLCO2A1 in heterozygous status (NM_005630.3: c.234+1G > A, c.1523_1524delCT, c.1625G > A and c.31delC), and the others carried homozygous pathogenic variants. For heterozygous forms, we found no additional pathogenic variant in HPGD or SLCO2A1. PHO can be a dominant form with age at disease onset later than that for the recessive form. This dominant form is not exceptional in young adults. In conclusion, both modes of inheritance of PHO explain the clinical variability and the difference in age at disease onset. Molecular analysis is especially required in the incomplete form to distinguish it from secondary hypertrophic osteoarthropathy.

Bone Geometry, Density, Microstructure, and Biomechanical Properties in the Distal Tibia in Patients With Primary Hypertrophic Osteoarthropathy Assessed by Second-Generation High-Resolution Peripheral Quantitative Computed Tomography.

Periosteosis refers to pathological woven bone formation beneath the cortical bone of the long bones. It is an imaging hallmark of primary hypertrophic osteoarthropathy (PHO) and also considered as one of the major diagnostic criteria of PHO patients. Up to date, detailed information on bone quality changes in long bones of PHO patients is still missing. This study aimed to evaluate bone microarchitecture and bone strength in PHO patients by using high-resolution peripheral quantitative computed tomography (HR-pQCT). The study comprised 20 male PHO patients with the average age of 27.0 years and 20 age- and sex-matched healthy controls. The areal bone mineral density (aBMD) was assessed at the lumbar spine (L1 -L4 ) and hip (total hip and femoral neck) by dual-energy X-ray absorptiometry (DXA). Bone geometry, volumetric bone mineral density (vBMD), and microstructure parameters at the distal tibia were evaluated by using HR-pQCT. Bone strength was evaluated by finite element analysis (FEA) based on HR-pQCT screening at distal tibia. Urinary prostaglandin E2 (PGE2 ), serum phosphatase (ALP), beta-C-telopeptides of type I collagen (ß-CTX), soluble receptor activator of nuclear factor-κB ligand (sRANKL), osteoprotegerin (OPG), and neuronal calcitonin gene-related peptide (CGRP) were investigated. As compared with healthy controls, PHO patients had larger bone cross-sectional areas; lower total, trabecular, and cortical vBMD; compromised bone microstructures with more porous cortices, thinned trabeculae, reduced trabecular connectivity, and relatively more significant resorption of rod-like trabeculae at distal tibia. The apparent Young's modulus was significantly lower in PHO patients. The concentration of PGE2 , biomarkers of bone resorption (ß-CTX and sRANKL/OPG ratio), and the neuropeptide CGRP were higher in PHO patients versus healthy controls. PGE2 level correlated negatively with vBMD and estimated bone strength and positively with bone geometry at distal tibia. The present HR-pQCT study is the first one illustrating the microarchitecture and bone strength features in long bones. © 2021 American Society for Bone and Mineral Research (ASBMR).

Complete form of pachydermoperiostosis

Abstract Pachydermoperiostosis (PDP) or primary hypertrophic osteoarthropathy (PHO) is a rare hereditary disease characterized by digital clubbing, pachydermia, and periostosis. Its pathogenesis is uncertain and the diagnosis is based on clinical and radiological data. A complete form of the syndrome is reported in a male patient with disease onset in adolescence, with compatible clinical and radiological findings, presenting the three cardinal findings as well as other associated manifestations, such as hyperhidrosis and acne.

Complete form of pachydermoperiostosis.

Pachydermoperiostosis (PDP) or primary hypertrophic osteoarthropathy (PHO) is a rare hereditary disease characterized by digital clubbing, pachydermia, and periostosis. Its pathogenesis is uncertain and the diagnosis is based on clinical and radiological data. A complete form of the syndrome is reported in a male patient with disease onset in adolescence, with compatible clinical and radiological findings, presenting the three cardinal findings as well as other associated manifestations, such as hyperhidrosis and acne.

Primary hypertrophic osteoarthropathy related gastrointestinal complication has distinctive clinical and pathological characteristics: two cases report and review of the literature.

BACKGROUND: Primary hypertrophic osteoarthropathy (PHO) is a rare disease related to HPGD and SLCO2A1 gene mutation. Gastrointestinal involvement of PHO is even rarer with unknown pathogenesis. Clinical features of GI complication in PHO mimics other auto-immune based bowel entities, such as inflammatory bowel diseases and cryptogenic multifocal ulcerous stenosing enteritis (CMUSE). We aimed to analyze the clinical, genetic, radiological and pathological features of Chinese patients with PHO and determine the difference between PHO patients presenting with and without GI involvement. METHODS: We reported two PHO cases with gastrointestinal involvement and reviewed all the studies of PHO in Chinese population published from January 1, 2000, to April 30, 2018. Clinical and genetic presentations of PHO in Chinese patients were analyzed. We compared the characteristics of those patients with gastrointestinal involvement against those without. RESULTS: The two patients were both males with complete-form PHO for more than 10 years. GI related symptoms included diarrhea, chronic gastrointestinal hemorrhage, incomplete intestinal obstruction, anemia, and edema, which were unresponsive to etoricoxib treatment. Radiological examinations revealed segmental intestinal stenosis and thickened intestinal wall. Endoscopic findings included multiple ulcers and mucosal inflammation. Both patients had mutations of SLCO2A1 according to sequence analysis. The surgical pathology revealed chronic inflammation involving the intestinal mucosa and submucosa, similar to histological changes in CMUSE. According to the systemic review of 158 Chinese patients with PHO, 17.2% had gastrointestinal involvement, including peptic ulcer, gastric polyps, hypertrophic gastritis, and segmental intestinal stenosis. Patients with gastrointestinal involvement were more likely to have anemia (40.0% vs. 4.5%, P < 0.001), hypoalbuminemia (16.7% vs. 0.9%, P = 0.003), and myelofibrosis (19.0% vs. 0.9%, P = 0.002) than those without. Most patients with gastrointestinal complication had SLCO2A1 mutation (86.7%, 13 /15). CONCLUSIONS: Digestive tract involvement is uncommon in patients with PHO and often presents with anemia, and hypoalbuminemia resulted from intestinal inflammation. The intestinal pathologic characteristics are distinct from Crohn's disease but similar to CMUSE. Mutations in SLCO2A1 might be the pathogenic cause of GI involvement of PHO. NSAIDs may not be effective for PHO patients with gastrointestinal complications.

Hypertrophic osteoarthropathy in an adult macaque.

OBJECTIVE: To evaluate through differential diagnosis whether hypertrophic osteoarthropathy was present on an adult macaque skeleton. MATERIALS: Skeletal remains of a well-preserved adult macaque (Macaca) of unknown species curated by the archaeology department at University College London. METHODS: Macroscopic and radiographic evaluation of pathological lesions. RESULTS: Widespread bilateral and symmetrical periosteal new bone growth primarily affecting the limbs was observed. CONCLUSION: A careful differential diagnosis of the lesions and comparison with previously published cases of hypertrophic osteoarthropathy among humans and non-humans suggests this animal displays a case of Hypertrophic osteoarthropathy. SIGNIFICANCE: Only been three reported cases of HOA in non-human primates have been reported, and all were apes. This study serves as the first reported case of HOA among non-hominoid simians, providing a detailed description of the skeletal lesions to aid future with paleopathological analyses. LIMITATIONS: Small sample sizes for comparison and lack of context for this specimen limits discussion of the scope of this disease among non-human primates. SUGGESTIONS FOR FURTHER RESEARCH: Re-evaluate skeletal collections which have not been subject to recent osteological and pathological analysis.

Pachydermoperiostosis (Touraine-Solente-Gole syndrome): a case report.

BACKGROUND: Pachydermoperiostosis (PDP) is a rare disorder characterized by clubbing of the fingers, thickening of the skin (pachyderma), and excessive sweating (hyperhidrosis). It typically appears during childhood or adolescence, often around the time of puberty, and progresses slowly. Clinical presentations of PDP can be confused with secondary hypertrophic osteoarthropathy, psoriatic arthritis, rheumatoid arthritis, thyroid acropachy, and acromegaly. CASE PRESENTATION: A Mongolian male, aged 19 years, resident of a hilly district of Nepal, with history of consanguinity, presented to our outpatient department with chief complaints of pain and swelling in both hands and feet for 6 years. The pain was insidious in onset, throbbing in nature, and not relieved by over-the-counter medications. The patient also complained of profuse sweating, progressive enlargement of hands and feet, and gradual coarsening of facial features. On examination there were marked skin folds in the forehead, face, and eyelids. Clubbing and swelling of bilateral knee joints and ankle joints was also evident. He was subsequently investigated extensively for acromegaly. Insulin-like growth factor-1 level and oral glucose tolerance test were normal. Radiography of various bones showed periosteal hypertrophy with subperiosteal bone formation. CONCLUSIONS: PDP should be considered as a differential diagnosis when a patient presents with hypertrophic osteoarthropathy and acromegalic features.

Effectiveness of non-steroidal anti-inflammatory drugs among patients with primary hypertrophic osteoarthropathy: A systematic review.

BACKGROUND: Primary hypertrophic osteoarthropathy (PHO), also known as pachydermoperiostosis is a rare genetic disease which predominantly affects skin, bone and soft connective tissue. It is characterized by the triad of pachydermia, digital clubbing and periostosis of long bones. Arthralgia or arthritis is also present in most of the cases. Genetic studies have identified the impaired PGE2 metabolism as a culprit for hypertrophic osteoarthropathy in PHO cases. We conducted a systematic review to examine the effectiveness of Non-Steroidal Anti-Inflammatory Drugs (NSAIDs), a PGE2 synthesis blocker to reduce the symptoms among PHO patients. METHODS: We searched the evidence in five databases; Cochrane Library, CINAHL, EMBASE, MEDLINE, and PubMed. We reported the evidence using narrative synthesis. RESULTS: Out of 238 identified studies, we selected 26 for the synthesis. All were case reports which included a total of 54 patients. Among them, 39 patients were treated with at least one type of NSAIDs. Around 70% of the patients treated with NSAIDs had clinical improvement for their symptoms, mostly arthritis or arthralgia symptoms. CONCLUSION: NSAIDs were effective in improving arthralgia or arthritis symptoms in majority of the PHO patients. Therefore, we recommend the use of NSAIDs in PHO patients to treat arthralgia or arthritis.

Interleukin-6, tumor necrosis factor-alpha and receptor activator of nuclear factor kappa ligand are elevated in hypertrophic gastric mucosa of pachydermoperiostosis.

Pachydermoperiostosis (PDP) is a rare inherited multisystem disease characterized with digital clubbing, pachydermia and periostosis. Variants in either HPGD or SLCO2A1 that interrupt the prostaglandin E2 (PGE2) pathway have been shown to be involved in PDP. Here, in addition to six confirmed variants in HPGD or SLCO2A1, we identified four novel SLCO2A1 variants in eight PDP patients from seven Chinese Han families. In addition, gastric mucosa hyperplasia was observed in all affected individuals and interleukin-6 (IL-6), tumor necrosis factor-alpha (TNFα) and receptor activator of nuclear factor kappa ligand (RANKL) expression were elevated in hypertrophic gastric mucosa. Two of eight patients who had severe arthralgia were treated with celecoxib. After three months, their arthralgia was partly relieved and IL-6, TNFα and RANKL expression were decreased in accordance with their relieved hypertrophic gastric mucosa. Our study broadens the variation spectrum of SLCO2A1 and suggests that the gastric mucosa hyperplasia might be a common characteristic of PDP. Moreover, celecoxib would be a considerable choice for PDP patients. We also revealed that IL-6, TNFα and RANKL may play important roles in the molecular mechanisms of gastric mucosa hyperplasia in PDP for the first time.

Clinical, Biochemical, and Genetic Features of 41 Han Chinese Families With Primary Hypertrophic Osteoarthropathy, and Their Therapeutic Response to Etoricoxib: Results From a Six-Month Prospective Clinical Intervention.

Primary hypertrophic osteoarthropathy (PHO) is a rare inherited disease caused by genetic defects in the prostaglandin metabolism pathway; disturbed prostaglandin E2 (PGE2 ) catabolism resulting in increased PGE2 level is suggested in the pathogenesis. Forty-three Han Chinese patients with PHO were studied and 41 of them were treated. Mutations in the HPGD gene, causing hypertrophic osteoarthropathy, primary, autosomal recessive 1 (PHOAR1; OMIM 259100), were identified in seven patients, and mutations in the SLCO2A1 gene, causing hypertrophic osteoarthropathy, primary, autosomal recessive 2 (PHOAR2; OMIM 614441), were identified in 36 patients. Clinical phenotypes of PHO varied, ranging from mild isolated finger clubbing to severe pachydermia and disabling joint swelling, even within families. Circulating PGE2 metabolism features of PHOAR2 were different from those of PHOAR1. Different frequency and severity of pachydermia between the subgroups were also indicated. A percentage of PHOAR2 patients suffered from gastrointestinal hemorrhage, but this symptom was not observed in the PHOAR1 subgroup. Clinical evidence highlighted the essential role of sex hormones in prostaglandin transporter regulation with respect to PHOAR2 onset, although no significant associations of urinary PGE2 or PGE-M with sex hormones were identified. Treatment with etoricoxib, a selective cyclooxygenase-2 inhibitor, was proved to be beneficial and safe. We detected its notable efficacy in decreasing urinary PGE2 levels in the majority of the enrolled patients during 6 months of intervention; clinical phenotypes assessed, including pachydermia, finger clubbing, and joint swelling, were improved. We found no visible evidence of a positive effect of etoricoxib on periostosis; however, significant links between urinary PGE2 and serum bone turnover markers indicated a potential role of decreased PGE2 in periostosis management. This is the largest reported cohort of subjects genetically diagnosed with PHO. For the first time, we systematically investigated the biochemical and clinical differences between PHOAR1 and PHOAR2, and prospectively showed the positive efficacy and safety of etoricoxib for PHO patients. © 2017 American Society for Bone and Mineral Research.

[A boy with digital clubbing]. / Een jongen met trommelstokvingers.

A 4-year-old boy was referred because of pan-digital clubbing and watch-glass nails. Other remarkable findings were: surgical closure of a patent arterial duct, decreased knee-mobility and consanguineous parents. This combination is suggestive for primary hypertrophic osteoarthropathy (PHO; #OMIM 259100). PHO was proven by his homozygous mutation of the 15-hydroxyprostaglandine dehydroxygenase-gene.

Hypertrophic Osteoarthropathy: Clinical and Imaging Features.

Hypertrophic osteoarthropathy (HOA) is a medical condition characterized by abnormal proliferation of skin and periosteal tissues involving the extremities and characterized by three clinical features: digital clubbing (also termed Hippocratic fingers), periostosis of tubular bones, and synovial effusions. HOA can be a primary entity, known as pachydermoperiostosis, or can be secondary to extraskeletal conditions, with different prognoses and management implications for each. There is a high association between secondary HOA and malignancy, especially non-small cell lung cancer. In such cases, it can be considered a form of paraneoplastic syndrome. The most prevalent secondary causes of HOA are pulmonary in origin, which is why this condition was formerly referred to as hypertrophic pulmonary osteoarthropathy. HOA can also be associated with pleural, mediastinal, and cardiovascular causes, as well as extrathoracic conditions such as gastrointestinal tumors and infections, cirrhosis, and inflammatory bowel disease. Although the skeletal manifestations of HOA are most commonly detected with radiography, abnormalities can also be identified with other modalities such as computed tomography, magnetic resonance imaging, and bone scintigraphy. The authors summarize the pathogenesis, classification, causes, and symptoms and signs of HOA, including the genetics underlying the primary form (pachydermoperiostosis); describe key findings of HOA found at various imaging modalities, with examples of underlying causative conditions; and discuss features differentiating HOA from other causes of multifocal periostitis, such as thyroid acropachy, hypervitaminosis A, chronic venous insufficiency, voriconazole-induced periostitis, progressive diaphyseal dysplasia, and neoplastic causes such as lymphoma. ©RSNA, 2016.

Pachydermoperiostosis.

A case of Pachydermoperiostosis (PDP) presented to us in rheumatology clinic with complaints of enlargement and broadening of bilateral hands and feet, grade IV digital clubbing, coarsening of facial features, excessive sweating of the palms, soles during summers.

Identification of the Mutations in the Prostaglandin Transporter Gene, SLCO2A1 and Clinical Characterization in Korean Patients with Pachydermoperiostosis.

Pachydermoperiostosis (PDP), or primary hypertrophic osteoarthropathy, is a rare genetic disease affecting both skin and bones. Both autosomal dominant with incomplete penetrance and recessive inheritance of PDP have been previously confirmed. Recently, hydroxyprostaglandin dehydrogenase (HPGD) and solute carrier organic anion transporter family member 2A1 (SLCO2A1) were reported as pathogenic genes responsible for PDP. Both genes are involved in prostaglandin E2 (PGE2) degradation. We aimed to identify responsible genes for PDP and the clinical features in Korean patients with PDP. Six affected individuals and their available healthy family members from three unrelated Korean families with PDP were studied. All of the patients displayed complete phenotypes of PDP with finger clubbing, pachydermia, and periostosis. Mutation analysis revealed a novel heterozygous mutation in the SLCO2A1 gene at nucleotide 302 causing a substitution of the amino acid isoleucine to serine at codon 101 (p.IIe101Ser) in affected individuals. We also identified known SLCO2A1 mutations, one homozygous for c.940+1G>A, and another compound heterozygous for c.940+1G>A and c.1807C>T (p.Arg603*) from two PDP families. Genetic analyses of the PDP patients showed no abnormality in the HPGD gene. Our study further supports the role of mutations in the SLCO2A1 gene in the pathogenesis of PDP and could provide additional clues to the genotype-phenotype relations of PDP.