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.

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.

Digital clubbing: forms, associations and pathophysiology.

Among proposed mechanisms to explain digital clubbing, the release of cytokines, specifically vascular endothelial growth factor and platelet-derived growth factor, from aggregated platelets and megakaryocytes has emerged as the most likely explanation. This review describes these and other contributory processes.

Pachydermoperiostosis, a unique entity with distinctive clinical features.

Pachydermoperiostosis, which occurs more frequently in men, is a rare entity with distinctive clinical features and an insidious onset.. We report the case of a 30-year-old man with a one-year history of acropachy, arthralgias, hiperhidrosis, and progressive skin thickening of the face and scalp. The radiological findings were consistent with periostosis and the histopathological analysis from a facial skin biopsy showed a pandermal increase in the thickness and number of collagen bundles. The pathogenesis of PDP is currently unknown, although an increased secretion of prostaglandin E2 (PGE2), which stimulates the overexpression of vascular endothelial growth factor (VEGF), has been suggested as a major factor. No specific treatment exists; however, in most cases, the disease tends to stabilize over time.

Aberrant CD200/CD200R1 expression contributes to painful synovium hyperplasia in a patient with primary hypertrophic osteoarthropathy.

We present a case of hypertrophic osteoarthropathy (PHO), with painful synovium hyperplasia involving both knees that was refractory to corticosteroid treatment. His rheumatoid factor and anti-CCP antibody was negative, and his serum ESR and CRP level was within normal range. Histological examination of the synovium obtained from his right knee revealed endothelial hyperplasia and vascular thickening without inflammation that was in association with aberrant expression of CD200/CD200R1, which highlighted the importance of aberrant CD200/CD200R1 in the regulation of the endothelial activation that contributed to the development of synovium hyperplasia in this PHO patient.

Mutations in the SLCO2A1 gene and primary hypertrophic osteoarthropathy: a clinical and biochemical characterization.

CONTEXT: We previously demonstrated that deficiency of the prostaglandin transporter (SLCO2A1) is a cause of primary hypertrophic osteoarthropathy (PHO). However, its clinical and metabolic characteristics have not been well defined. OBJECTIVE: The objective of the study was to expand this mutational spectrum to better delineate the SLCO2A1 deficiency phenotype and investigate the clinical and metabolic characteristics of a cohort of subjects with PHO. DESIGN, SETTING, PATIENTS, AND MAIN OUTCOME MEASURE: Eleven affected individuals and their available healthy family members from 9 unrelated Chinese families with PHO (7 of which were previously undescribed) were clinically studied. The SLCO2A1 gene was screened and analyzed. Urinary levels of prostaglandin E2 (PGE2) and prostaglandin E metabolite (PGE-M) were measured using competitive ELISAs. The serum levels of total T, estradiol, sex hormone-binding protein, LH, FSH, and fasting gastrin were detected. RESULTS: Nine different SLCO2A1 mutations were identified in affected individuals in the 7 previously undescribed families, 7 of which (Glu165X, Ala286GlnfsX35, Gln356AlafsX77, Gly369Asp, Gly379Glu, Glu465Lys, and c.861+2T>C) were novel. The urinary levels of PGE2 and PGE-M were much higher in the SLCO2A1-deficient individuals and decreased with age. There was no relationship between sex hormones and PGE2 or PGE-M. There was no significant difference in the levels of fasting serum gastrin between PHO patients with watery diarrhea and their relatives. CONCLUSIONS: The present findings broaden the allelic spectrum of SLCO2A1 mutations. The urinary levels of PGE2 and PGE-M in the SLCO2A1-deficient individuals decreased with age. The measurement of the excreted PGE2 and PGE-M may have implications in the differential diagnosis, treatment, and follow-up of PHO.

Primary hypertrophic osteoarthropathy: an update.

Digital clubbing, which has been recognized as a sign of systemic disease, is one of the most ancient diseases. However, the pathogenesis of clubbing and hypertrophic osteoarthropathy has hitherto been poorly understood. The study of a clinically indistinguishable idiopathic form (primary hypertrophic osteoarthropathy, PHO) provides an opportunity to understand the pathogenesis of hypertrophic osteoarthropathy. Current advances in the study of PHO are discussed. The impaired metabolism of prostaglandin E2 (PGE2) plays a central role in its pathogenesis.

Identification of mutations in the prostaglandin transporter gene SLCO2A1 and its phenotype-genotype correlation in Japanese patients with pachydermoperiostosis.

BACKGROUND: Pachydermoperiostosis (PDP) is a rare genetic disorder characterized by 3 major symptoms: pachydermia including cutis verticis gyrata (CVG), periostosis, and finger clubbing. Recently, a homozygous mutation in the gene HPGD, which encodes 15-hydroxyprostaglandin dehydrogenase (15-PGDH), was found to be associated with PDP. However, mutations in HPGD have not been identified in Japanese PDP patients. OBJECTIVE: We aimed to identify a novel responsible gene for PDP using whole exome sequencing by next-generation DNA sequencer (NGS). METHODS: Five patients, including 2 patient-parent trios were enrolled in this study. Entire coding regions were sequenced by NGS to identify candidate mutations associated with PDP. The candidate mutations were subsequently sequenced using the Sanger method. To determine clinical characteristics, we analyzed histological samples, as well as serum and urinary prostaglandin E2 (PGE2) levels for each of the 5 PDP patients, and 1 additional patient with idiopathic CVG. RESULTS: From initial analyses of whole exome sequencing data, we identified mutations in the solute carrier organic anion transporter family, member 2A1 (SLCO2A1) gene, encoding prostaglandin transporter, in 3 of the PDP patients. Follow-up Sanger sequencing showed 5 different SLCO2A1 mutations (c.940+1G>A, p.E427_P430del, p.G104*, p.T347I, p.Q556H) in 4 unrelated PDP patients. In addition, the splice-site mutation c.940+1G>A identified in 3 of 4 PDP patients was determined to be a founder mutation in the Japanese population. Furthermore, it is likely that the combination of these SLCO2A1 mutations in PDP patients is also associated with disease severity. CONCLUSION: We found that SLCO2A1 is a novel gene responsible for PDP. Although the SLCO2A1 gene is only the second gene discovered to be associated with PDP, it is likely to be a major cause of PDP in the Japanese population.

Prostaglandin transporter mutations cause pachydermoperiostosis with myelofibrosis.

Pachydermoperiostosis, or primary hypertrophic osteoarthropathy (PHO), is an inherited multisystem disorder, whose features closely mimic the reactive osteoarthropathy that commonly accompanies neoplastic and inflammatory pathologies. We previously described deficiency of the prostaglandin-degrading enzyme 15-hydroxyprostaglandin dehydrogenase (HPGD) as a cause of this condition, implicating elevated circulating prostaglandin E(2) (PGE(2)) as causative of PHO, and perhaps also as the principal mediator of secondary HO. However, PHO is genetically heterogeneous. Here, we use whole-exome sequencing to identify recessive mutations of the prostaglandin transporter SLCO2A1, in individuals lacking HPGD mutations. We performed exome sequencing of four probands with severe PHO, followed by conventional mutation analysis of SLCO2A1 in nine others. Biallelic SLCO2A1 mutations were identified in 12 of the 13 families. Affected individuals had elevated urinary PGE(2), but unlike HPGD-deficient patients, also excreted considerable quantities of the PGE(2) metabolite, PGE-M. Clinical differences between the two groups were also identified, notably that SLCO2A1-deficient individuals have a high frequency of severe anemia due to myelofibrosis. These findings reinforce the key role of systemic or local prostaglandin excess as the stimulus to HO. They also suggest that the induction or maintenance of hematopoietic stem cells by prostaglandin may depend upon transporter activity.

Involvement of Wnt signaling in dermal fibroblasts.

Pachydermoperiostosis (PDP) is a rare disease characterized by unique phenotypes of the skin and bone, such as thick skin, implying that it may be caused by dysregulation of mesenchymal cells. The aim of this study is to examine the roles of dermal fibroblasts in the pathogenesis of pachydermia in association with Wnt signaling. The numbers of cultured fibroblasts were compared between healthy donors and PDP patients, and mRNA expression profiles in cultured dermal fibroblasts were examined by DNA microarray analysis and real-time reverse transcription-PCR. DKK1 and beta-catenin protein expressions were also evaluated by immunohistochemistry in the skin. To evaluate the in vivo roles of DKK1 in mice, DKK1 small interfering RNA was injected to the ears. We found that PDP fibroblasts proliferated more than control fibroblasts and that mRNA expression of a Wnt signaling antagonist, DKK1, was much lower in PDP fibroblasts than in normal ones. Consistently, decreased expression of DKK1 in fibroblasts and enhanced expression of beta-catenin were noted in PDP patients. Moreover, recombinant human DKK1 protein decreased the proliferation of dermal fibroblasts. In accord with the above human studies, intradermal injections of DKK1 small interfering RNA into mouse ears increased ear thickness as seen in PDP. Our findings suggest that enhanced Wnt signaling contributes to the development of pachydermia by enhancing dermal fibroblast functions.

Prostaglandin E2 and bone turnover markers in the evaluation of primary hypertrophic osteoarthropathy (pachydermoperiostosis): a case report.

Primary hypertrophic osteoarthropathy, or pachydermoperiostosis (PDP), is an infrequent genetic condition characterized by digital clubbing, periostosis, and pachydermia and is distinct from a more common form, secondary hypertrophic osteoarthropathy, which always associates with an underlying cause (frequently pulmonary or cardiac disease). The diagnosis of this disorder as well as its clinical evaluation can be difficult. We report a 15-year-old boy presenting with intermittent arthralgias and clubbing of fingers and toes for the previous 2 years. The ankles and knees were enlarged, and X-rays showed periosteal apposition. The search for a secondary cause was negative. The skin appearance was normal, but a skin biopsy was indicative of pachydermia, further confirming the diagnosis of PDP. Bone turnover markers were increased at diagnosis and progressively decreased during follow-up; prostaglandin E(2), a recently implicated mediator of this disorder, was markedly elevated. In the present case, carrying out a skin biopsy helped us to diagnose this condition. In addition, bone turnover markers were useful for monitoring the disease activity; whereas, increased prostaglandin E(2) levels seems to confirm the role of this mediator in the etiopathogenesis of this disorder.

Alteration of matrix macromolecule synthesis by fibroblasts from a patient with pachydermoperiostosis.

Pachydermoperiostosis (primary hypertrophic osteoarthropathy) is a very rare genetic disease characterized by pachydermia, periostosis, arthralgia, and finger clubbing. Its pathophysiology is still unclear, but previous studies have reported connective tissue hypertrophy in the skin of these patients. We investigated the synthesis of collagen, fibronectin, and proteoglycans by fibroblasts from affected and unaffected skin from one patient with pachydermoperiostosis and four normal donors. We found that collagen synthesis was largely decreased in fibroblasts from the diseased skin, whereas the synthesis of the small dermatan-sulfate-containing proteoglycan decorin strongly increased. Fibroblasts from the unaffected skin of the patient exhibited syntheses of these macromolecules similar to control fibroblasts from healthy donors. Northern blot and dot blot analyses showed decreased pro alpha 1 (I) collagen in patient's affected and unaffected skin fibroblasts whereas increased decorin mRNA levels were found in fibroblasts from the patient's affected skin. No change in cell proliferation was observed. These data demonstrate an alteration of fibroblast biosynthetic activity in the skin lesions of pachydermoperiostosis, which may be responsible, at least in part, for the patient's phenotype.

Synthesis and degradation of connective tissue macromolecules in pachydermoperiostosis (PDP): evidence for altered processing of plasminogen activator inhibitor-1 (PAI-1).

Pachydermoperiostosis (PDP) is a hereditary disease with hyperostosis, clubbing of fingers, coarse skin and thickening of bones. Previous studies have disclosed some abnormality in the connective tissue in these patients. The purpose of the present study was to investigate connective tissue pathology in one family with PDP using fibroblast cultures. Fibroblastic cells were established from both the affected and healthy looking skin of 2 patients with PDP, and the expression of types I and III collagen, 92 kDa and 72 kDa gelatinases, metalloproteinase inhibitor (TIMP-1), human retinoic acid receptor and transforming growth factor beta (TGF beta) was analyzed. The modulation of glycoprotein synthesis, and of plasminogen activators and their inhibitors by TGF beta in vitro were also studied. The results indicated that collagen genes and gelatinases were similarly expressed in PDP and control cells, as well as the human retinoic acid receptor. TGF beta stimulated, both in PDP cells and normal cells, the synthesis of fibronectin, procollagen and plasminogen activator inhibitor-l (PAI-1), but qualitative differences could not be found. Proteolytically processed forms of PAI-1 were detected in PDP cell lines.

Pachydermoperiostosis: study of epidermal growth factor and steroid receptors.

Pachydermoperiostosis is a rare osteo-cutaneous disease characterized by hypertrophy of bones and surrounding soft tissues. The cutaneous manifestations include coarsening of facial features, cutis verticis gyrata, digital clubbing, hyperhidrosis and seborrhoea. The pathogenetic mechanism of the disease is still debated, and proposed aetiological factors include genetic influences, anomalies in fibroblast activity, or alteration in peripheral blood flow. We studied a patient with the incomplete form of pachydermoperiostosis, assessing epidermal growth factor receptor (EGF-R) and sex hormone steroid receptors (SR) in the affected skin, and also evaluating the urinary excretion of EGF. The results showed high levels of nuclear steroid receptors, increased cytosolic oestrogen receptors, and no detectable progesterone and androgen cytosolic receptors. EGF-R was also undetectable, and the urinary excretion of EGF was elevated. These findings suggest that the increased tissue sensitivity to circulating sex-steroids could induce enhanced tissue EGF/transforming growth factor alpha (TGF-alpha) production and utilization. The SR-EGF-R system could therefore be involved in determining hypertrophy of the affected tissues.

Pachydermoperiostosis: analysis of the connective tissue abnormality in one family.

BACKGROUND: Pachydermoperiostosis (PDP) is a rare hereditary disease characterized by hyperostosis, clubbing of fingers, coarse skin, and abnormalities in other organs, such as the gastrointestinal tract. Previous studies have disclosed several abnormalities in the connective tissue in these patients. OBJECTIVE: The purpose of the study was to investigate connective tissue abnormalities in one family with PDP. METHODS: Clinical features were evaluated; x-ray, immunohistochemical, and electronmicroscopic studies were performed; and markers of collagen metabolism and lysosomal enzymes were determined. RESULTS: Immunohistochemical and ultrastructural studies revealed accumulation of tenascin, glycosaminoglycans, and fibrillar material in apparently disorganized microfibrils of elastic fibers. Osteocalcin levels in the serum were increased, but synthesis and degradation markers of collagen in the serum were not altered. No evidence of a lysosomal enzyme deficiency was found. CONCLUSION: Acidic mucopolysaccharides and some fibrillar material accumulate in the dermis of patients with PDP. Increased levels of osteocalcin in serum indicate higher osteoblastic activity. Markers of synthesis and degradation of collagen were not altered.

Increased collagen synthesis in skin fibroblasts from patients with primary hypertrophic osteoarthropathy. Evidence for trans-activational regulation of collagen transcription.

OBJECTIVE: To investigate collagen synthesis in skin fibroblasts from patients with primary hypertrophic osteoarthropathy (HOA), a disorder characterized clinically by skin thickening. METHODS: Collagenase-digestible protein, messenger RNA (mRNA) levels, and transcriptional activity of the alpha 1(I) procollagen gene were assessed in skin-derived fibroblast lines. RESULTS: Compared with fibroblasts from uninvolved skin, fibroblasts from involved skin had elevated levels of collagen synthesis and alpha 1(I) procollagen mRNA, and increased transcriptional activity of the alpha 1(I) procollagen promoter. CONCLUSION: Abnormalities of collagen synthesis in fibroblasts from patients with primary HOA can be accounted for, at least in part, by a trans-activated up-regulation of collagen transcription.

Hypertrophic hepatic osteoarthropathy. Clinical, roentgenologic, biochemical, hormonal and cardiorespiratory studies, and review of the literature.

Twenty patients with biopsy proved liver disease, and roentgenologic features of hypertrophic osteoarthropathy have been studied, and the literature has been reviewed. The syndrome is a rare association of many chronic liver diseases, including primary biliary cirrhosis, bile duct carcinoma, benign bile duct stricture, chronic active hepatitis, posthepatitic cirrhosis and alcoholic cirrhosis. Patients may be asymptomatic, although bone pain, arthralgia or arthritis may be presenting symptoms. Ninety per cent of the patients are clinical jaundiced at the time of diagnosis, and 95 per cent have digital clubbing. The distal tibia and fibula are the first bones to become involved, although wrist, foot bones, femurs, hand bones and humeri may be affected in order of frequency. There is no correlation between the presence of esophageal varices or surgical portacaval shunts and the extent of the syndrome, neither is there a correlation with the degree of liver function impairment. Serum calcium and phosphate levels are normal, as is urinary hydroxyproline and estrogen excretion. There was no evidence to implicate elevated levels of growth hormone or overdosage of vitamin A. Although the majority of patients tested had mild arterial hypoxemia, increased cardiac output and evidence of right to left shunting, these were also present in disease-matched control subjects without osteoarthropathy. For screening purposes, patients with chronic liver disease and clubbing should have roentgenologic studies of the lower tibias and fibulas, to select those patients suitable for a more extensive skeletal survey.

Identification of hydroxyapatite crystals in synovial fluid.

A semiquantitative technique employing (14C) ethane-1-hydroxy 1, -1-diphosphonate (EHDP) binding has been used to detect crystals, presumably hydroxyapatite, in human synovial fluid samples which were handled to prevent the formation of artifactual mineral phase. Binding material was found in 29% of non-inflammatory and in none of inflammatory joint fluids. Nuclide binding material was strongly correlated with the presence of CPPD crystals and with radiographic evidence of cartilaginous degeneration.