A novel variant in the SLCO2A1 gene in a Chinese patient with chronic gastroenteropathy and primary hypertrophic osteoarthropathy.

BACKGROUND: Chronic enteropathy associated with SLCO2A1 gene (CEAS) results from loss-of-function variants in SLCO2A1, which encodes the prostaglandin transporter (PGT). CEAS follows an autosomal recessive inheritance pattern. To date, approximate 30 pathogenic variants have been reported in CEAS. METHODS: We performed whole exome sequencing (WES) to screen for potential pathogenic variants in a patient suspected of having CEAS, and confirmed a variant in SLCO2A1 using Sanger sequencing. We established an in vitro minigene model to compare splicing between wild type (WT) and mutant transcripts. Quantitative polymerase chain reaction (qPCR) was used to evaluate SLCO2A1 transcription in the stomach and colon tissues from the patient and a healthy control (HC). The transcripts were further cloned and sequenced. RESULTS: The patient had a novel, homozygous, recessive c.929A > G variant in exon 7 of SLCO2A1, which has not been previously reported in CEAS or PHO. This variant altered splicing, resulting in an exon 7-truncated transcript lacking 16 bases. No normal transcript was detected in the patient's stomach or colon tissue. qPCR also showed significantly decreased SLCO2A1 transcription compared to HC. CONCLUSION: A previously unreported variant caused defective SLCO2A1 splicing and reduced mRNA levels in a patient with CEAS and PHO. This research enhances understanding of CEAS and PHO pathophysiology and aids genetic counseling and diagnosis.

Role of bisphosphonates in hypertrophic osteoarthropathy: a systematic review.

BACKGROUND: The role of bisphosphonates (BP) in hypertrophic osteoarthropathy (HPOA) is unclear. We presented a case of primary HPOA and performed a systematic review of literature on the effect of BP on treatment response in primary and secondary HPOA. METHODS: The study was prospectively registered in PROSPERO (CRD42022343786). We performed a PubMed literature search that restricted to the English language. We included patients diagnosed with primary or secondary HPOA who received BP. The primary endpoint assessed was the effectiveness of BP on response to pain or arthritis. Secondary outcomes included timing, degree, and duration of response, comparison to other HPOA therapies, impact of BP on radiology, bone scan, bone turnover markers, and adverse effects of BP. RESULTS: Literature search retrieved only case reports. Forty-five patients (21 primary, 24 secondary HPOA) had received BP. Majority(88.3%) experienced improvement in pain or arthritis. Response was gradual for primary HPOA and within a median of 3 to 7 days for secondary HPOA after treatment with BP. Most patients had reduced bone scan uptake after BP. When other HPOA therapies were tried, half responded to BP after not having previously responded to other therapies, while a third received the treatments concurrently, making it difficult to attribute treatment response to a drug. Reporting of other secondary outcomes was very heterogenous and qualitative to draw conclusions. No major adverse effects have been reported for BP in HPOA. CONCLUSION: Bisphosphonates provide an effective and safe treatment option for primary and secondary HPOA. However, there is a lack of randomized controlled trials.

Genotype and phenotype characterization of primary hypertrophic osteoarthropathy type 2 and chronic enteropathy associated with SLCO2A1: Report of two cases and literature review.

Autosomal recessive type 2 primary hypertrophic osteoarthropathy (PHOAR2) and chronic enteropathy associated with SLCO2A1 (CEAS) are two entities caused by pathogenic variants (PVs) in the SLCO2A1 gene that can coexist or occur independently from one another. We report two cases of PHOAR2 in Mexico with concomitant CEAS and conducted a review of the literature of the reported cases of PHOAR2 and/or CEAS to analyze the relationship between their genotype and phenotype presentation. The patients from our Institution with classical PHOAR2 phenotype and CEAS, harbored SLCO2A1 c.547G > A and c.1768del variants. We reviewed 232 cases, of which 86.6% were of Asian origin, and identified 109 different variants in SLCO2A1. Intron 7, exon 13, and exon 4 were predominantly affected. The two most common PVs were c.940 + 1G > A and c.1807C > T. We found a statistically significant association between SLCO2A1 variants located in intron 7, exons 12, and 13 and the development of CEAS. Missense variants were more frequent in isolated PHOAR2, while a greater proportion of protein-truncating variants (PTVs) were found in CEAS. Further investigation is imperative to elucidate the underlying pathophysiological mechanisms associated with CEAS, thereby facilitating the identification of effective therapeutic interventions.

Paraneoplastic Polyarthritis in a Patient with Synchronous Lung and Colorectal Malignancy.

Arthritis is an unusual manifestation of paraneoplastic syndrome, appearing in a variety of cancers, including pulmonary and colorectal. It can often pose a diagnostic challenge to physicians, since it may be difficult to distinguish from more commonly encountered rheumatic illnesses. Moreover, synchronous cancers are rare and unexpected in patients with symmetrical polyarthritis. Hypertrophic pulmonary osteoarthropathy is to be considered in patients with polyarthritis and lung neoplasia. The aim of this report is to highlight the case of a patient presenting with paraneoplastic polyarthritis, which led to identifying the presence of underlying synchronous lung and colorectal malignancies. Lymph node biopsy was performed raising suspicion of Caplan's syndrome but lung lobectomy confirmed adenocarcinoma. Rheumatologists should be reacquainted with rheumatic manifestations in malignant diseases.

Pachydermoperiostosis: a case report of initial improvement with etoricoxib.

Introduction and importance: Pachydermoperiostosis (PDP) is a syndrome characterised by the triad of pachydermia, digital clubbing and periostosis of long bones and its scarce incidence and similarity in clinical features with acromegaly makes the diagnosis challenging. The elevated PGE2 levels have been hypothesised as one of its mechanisms and therapies have been targeted to inhibit this prostaglandin. Case presentation: A 25-year-old man with no comorbidities presented to OPD with a 10-year history of bilateral pain and swelling of the hands and feets associated with hyperhidrosis, grade IV clubbing and marked skin thickening on his forehead. X-rays revealed hyperostosis of the metacarpals, proximal and middle phalanges and periosteal bone formation with cortical thickening of the ankle joint. Tests done to rule out differentials such as thyroid acropachy, acromegaly, psoriatic arthritis were normal and a clinical diagnosis of PDP, a rare genetic disease characterised by pachyderma, digital clubbing and periostosis was made. Clinical discussion: The patient was managed conservatively with etoricoxib for 6 months on a follow-up basis. The symptoms were improving and a repeat X-ray showed partial improvement of soft tissue thickening and periostosis. Conclusion: PDP is a rare diagnosis with no clear consensus on a management approach. Its management with selective COX-2 inhibitors such as etoricoxib should be considered but its long-term effects should be studied further.

Primary hypertrophic osteoarthropathy: genetics, clinical features and management.

Primary hypertrophic osteoarthropathy (PHO) is a genetic disorder mainly characterized by clubbing fingers, pachydermia and periostosis. Mutations in the HPGD or SLCO2A1 gene lead to impaired prostaglandin E2 (PGE2) degradation, thus elevating PGE2 levels. The identification of the causative genes has provided a better understanding of the underlying mechanisms. PHO can be divided into three subtypes according to its pathogenic gene and inheritance patterns. The onset age, sex ratio and clinical features differ among subtypes. The synthesis and signaling pathways of PGE2 are outlined in this review. Cyclooxygenase-2 (COX-2) is the key enzyme that acts as the rate-limiting step for prostaglandin production, thus COX-2 inhibitors have been used to treat this disease. Although this treatment showed effective results, it has side effects that restrain its use. Here, we reviewed the genetics, clinical features, differential diagnosis and current treatment options of PHO according to our many years of clinical research on the disease. We also discussed probable treatment that may be an option in the future.

Takayasu's arteritis after a prolonged course of hypertrophic osteoarthropathy.

A 71-year-old male with hypertrophic osteoarthropathy was referred to our hospital because of a nocturnal fever and tenderness stretching from the left parotid region to the left front neck, in which antibacterials were ineffective. He was diagnosed with Takayasu's arteritis following findings of contrast-enhanced computed tomography and neck ultrasound. This is the first report to describe the development of Takayasu's arteritis after a prolonged course of typical hypertrophic osteoarthropathy, and the proposed hypertrophic osteoarthropathy and Takayasu's arteritis have common underlying pathophysiological factors.

Touraine-Solente-Gole syndrome: pathogenic variant in SLCO2A1 presented with polyarthralgia and digital clubbing.

BACKGROUND: Primary Hypertrophic Osteoarthropathy (PHO), also known as Touraine-Solente-Gole Syndrome, is a rare, multisystemic autosomal recessive disorder caused by pathogenic variants in the 15-hydroxyprostaglandin dehydrogenase (HPGD) or Solute Carrier Organic Anion Transporter Family Member 2A1 (SLCO2A1) genes. However, autosomal dominant transmission has also been described in some families with incomplete penetrance. PHO usually starts in childhood or adolescence, presenting with digital clubbing, osteoarthropathy, and pachydermia. We described a complete form of the syndrome in a male patient with a homozygous variant in the SLCO2A1 gene (c.1259G > T). CASE PRESENTATION: A 20-year-old male was referred to our Pediatric Rheumatology Clinic with a five-year history of painful and swollen hands, knees, ankles and feet, prolonged morning stiffness and relief with non-steroidal antiinflammatory drugs. He also reported late onset facial acne and palmoplantar hyperhidrosis. Family history was irrelevant and parents were non-consanguineous. On clinical examination, he presented clubbing of the fingers and toes, moderate acne and marked facial skin thickening with prominent scalp folds. He had hand, knee, ankles and feet swelling. Laboratory investigations showed elevated inflammatory markers. Complete blood count, renal and hepatic function, bone biochemistry were normal, as well as immunological panel. Plain radiographs revealed soft tissue swelling, periosteal ossification and cortical thickening of the skull, phalanges, femur and toe acroosteolysis. Due to the absence of other clinical signs suggesting a secondary cause, we suspected PHO. A genetic study revealed a likely pathogenic variant, c.1259G > T(p.Cys420Phe), in homozygosity in the SLCO2A1 gene, thus confirming the diagnosis. The patient started oral naproxen with significant clinical improvement. CONCLUSIONS: PHO should be kept in the differential diagnosis of inflammatory arthritis affecting children, often misdiagnosed as Juvenile Idiopathic Arthritis (JIA). To the best of our knowledge, this is the second genetically confirmed case of PHO in a Portuguese patient (first variant c.644 C > T), both made at our department.

Hypertrophic osteoarthropathy associated with lung cancer: Possible links among hypoxia-inducible factor-1α, vascular endothelial growth factor, and hypervascularization.

Hypertrophic osteoarthropathy (HOA) is a paraneoplastic syndrome, the exact pathogenesis of which remains to be elucidated. The case of a 69-year-old man who developed intractably painful HOA secondary to lung cancer is presented. Contrast-enhanced computed tomography of the chest showed an 80-mm solid nodule with a large low-density area. The patient was diagnosed as having stage IIIA undifferentiated non-small cell lung cancer. The combination of carboplatin and paclitaxel with bevacizumab reduced tumor size and plasma vascular endothelial growth factor (VEGF) levels, relieving his leg pain. On immunohistochemical examination, lung cancer cells were positive for VEGF. A hypoxic tumor microenvironment may have caused some lung cancer cells to express hypoxia-inducible factor-1α, which contributed, at least in part, to the production of VEGF. The deep dermis vessels showed proliferation in the shin, with their thickened walls positive for VEGF. These findings may encourage investigators to explore novel management strategies for painful HOA.

Case report: Novel homozygous HPGD variant leads to primary hypertrophic osteoarthropathy with intussusception and acro-osteolysis in a Chinese family.

Objective: To perform molecular genetic analysis of a patient diagnosed with primary hypertrophic osteoarthropathy (PHO) with malnourishment, intussusception, and acro-osteolysis. Case presentation: At the age of 7 years, a boy born to a consanguineous couple was diagnosed with PHO attributed to delayed closure of the cranial suture, eczema, clubbing of fingers, and swelling of the knee and ankle. Clinical characteristics and follow-up data for 3 years were collected and analyzed. Trio whole-exome sequencing (WES) and copy number variant sequencing were used to screen for causative genetic variants. Candidate variants of the patient and his parents were confirmed by Sanger sequencing. When he was 7 years old, trio WES found that he had biallelic novel variants c.498 + 1G > A, inherited from his parents, in the HPGD gene. The patient was markedly malnourished. Ultrasonography and computed tomography showed intussusception with a gradual expansion of the duodenum, localized intestinal wall thickening, and acro-osteolysis. Cross-sectional blood tests showed that the patient had continuously decreased levels of serum 25-hydroxy vitamin D and serum ferritin at the age of 7and 10 years. Conclusion: PHO due to HPGD defects is rare in pediatric patients, and finding homozygous novel c.498 + 1G > A has expanded the spectrum of causative variants of HPGD and provided a clue for genotype-phenotype correlation analysis. Similar to mouse model results, human HPGD deficiency may also cause abnormal digestive tract development, and related secondary vitamin D deficiency and acro-osteolysis should be considered in HPGD-related PHO.

Paraneoplastic musculoskeletal disorders: review and update for radiologists.

Rheumatic paraneoplastic syndromes are rare syndromes that occur at distant sites from the underlying tumor and may involve the bones, joints, fasciae, muscles, or vessels. In the absence of a known tumor, early recognition of a rheumatic syndrome as paraneoplastic permits dedicated work-up for, and potentially early treatment of an occult malignancy. Although there is a continuously growing list of paraneoplastic rheumatic disorders, not all of these disorders have a well-established association with a neoplastic process. The goals of this article are to review the clinical characteristics, diagnostic work-up, and imaging findings of well-documented rheumatic paraneoplastic disorders.

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.

Hypertrophic Osteoarthropathy: A Case of an Undifferentiated Polyarthritis.

Hypertrophic osteoarthropathy is a paraneoplastic syndrome and is considered an important secondary cause of rheumatic disease. It typically manifests as tibial and femoral bone pain, with arthralgia or synovitis of adjacent joints also being common findings. Usually, musculoskeletal symptoms accompany the course of the disease, disappearing with treatment of the neoplasm and recurring coincidentally with the tumor relapse. The authors report a case of a patient with hypertrophic osteoarthropathy, whose etiological study allowed the diagnosis of a lung adenocarcinoma, particularly challenging due to the patient's young age and the absence of associated symptoms.

Etoricoxib as a treatment of choice for patients with SLCO2A1 mutation exhibiting autosomal recessive primary hypertrophic osteoarthropathy: A case report.

We reported a 22-year-old Emirati male with autosomal recessive primary hypertrophic osteoarthropathy caused by a possibly pathogenic homozygous non-synonymous variant in the SLCO2A1 gene (NM_005630.3: c.289C>T, p. Arg97Cys) presenting with joint swelling, forehead furrowing, and significant clubbing in all fingers and toes. Currently, no standard treatments are approved for this disease; medical care is palliative and includes non-steroidal anti-inflammatory drugs, corticosteroids, tamoxifen, retinoids, and risedronate. Colchicine may be helpful for the pain due to subperiosteal new bone formation. Our patient was treated with etoricoxib 60 mg once daily and showed a significant clinical improvement at the 6-month mark that was reversed upon the withdrawal of this medication. This case report highlights the importance of placing etoricoxib among first-line therapy recommendations for cases with confirmed primary hypertrophic osteoarthropathy diagnosis. To the best of our knowledge, this is the only case of primary hypertrophic osteoarthropathy from the Middle Eastern population of Arab ethnicity that has responded to non-steroidal anti-inflammatory drug therapy.

Impact of highly effective CFTR modulator therapy on digital clubbing in patients with cystic fibrosis.

BACKGROUND: The association of certain disease processes with digital clubbing is well documented. Digital clubbing is often reversible after successful treatment of the underlying pathology, for example, after lung transplantation in patients with cystic fibrosis (CF). We examined the effect of highly effective Cystic Fibrosis Transmembrane Regulator (CFTR) modulators, defined for the purposes of this study as ivacaftor or the combination of ivacaftor, tezacaftor, and elexacaftor (ETI), on digital clubbing. MATERIALS AND METHODS: Clubbing index was measured on plaster of Paris casts of right index fingers obtained from 15 patients with cystic fibrosis, before and after initiation of CFTR modulator therapy. Similar measurements were made on casts for 9 cystic fibrosis patients who underwent lung transplantation. Measurements were made on the most recent casts available before treatment and the first cast available at least 3 months after initiation of treatment. The Wilcoxon signed-rank text was used to detect any significant difference in the pre- and post-treatment casts for each individual. RESULTS: A significant decrease in the clubbing index was found after both lung transplantation and treatment with highly effective CFTR modulator therapy. CONCLUSIONS: These results add to the body of evidence demonstrating the efficacy of highly effective CFTR modulator therapy, the first agents that act directly at the dysfunctional chloride channel responsible for CF. By demonstrating that CFTR modulator therapy is capable of reversing digital clubbing, this study suggests a beneficial effect on lung pathology aside from air flow and gas transfer.

[Bilateral periostitis and arthritis: about a case of hypertrophic osteoarthropathy]. / Périostite bilatérale et polyarthrite : à propos d'un cas d'ostéoarthropathie hypertrophique pneumique.

We report the case of a 67-year-old female patient presenting swelling of the hands and feet and pain in both legs. Clinical examination and bone scintigraphy identify the triad "digital clubbing - arthritis - bilateral periostitis of the long bones", leading to a diagnosis of hypertrophic osteoarthropathy, a syndrome usually associated with pulmonary neoplasia. The thoracic CT-scan, followed by a biopsy, effectively diagnosed a right upper lobe adenocarcinoma. Surgical treatment of the neoplasia allowed the resolution of the clinical complaints and the pathological scintigraphic findings.

Nous rapportons le cas d'une patiente de 67 ans présentant des gonflements des mains et des pieds ainsi que des douleurs des deux jambes. L'examen clinique et la scintigraphie osseuse identifient la triade «hippocratisme digital - arthrites - périostite bilatérale des os longs¼, permettant de poser un diagnostic d'ostéoarthropathie hypertrophique, un syndrome habituellement associé à une néoplasie pulmonaire. Le scanner thoracique, suivi d'une biopsie, ont en effet diagnostiqué un adénocarcinome localisé au niveau du lobe supérieur droit. La prise en charge chirurgicale de la néoplasie a permis la résolution des plaintes cliniques et de l'aspect scintigraphique pathologique.

Clinical and biochemical characteristics of 12 Chinese primary hypertrophic osteoarthropathy patients with HPGD mutations.

Primary hypertrophic osteoarthropathy (PHO) is a rare genetic disease mainly affecting the skeletal and skin. Two genes involved in prostaglandin degradation are known to be responsible for PHO: HPGD and SLCO2A1. HPGD gene mutation can cause PHO autosomal recessive 1 (PHOAR1). The purpose of the present study is to analyze the clinical and biochemical characteristics and HPGD gene mutations of 12 Chinese PHOAR1 patients. Twelve PHOAR1 patients from eleven families, including eleven males and one female, were enrolled in this study. Digital clubbing and periostosis came out to be the most common features, which always occur in the early childhood. We performed HPGD gene analysis and identified six novel (c.1A>G, c.34G>T, c.317T>A, c.475G>T, c.548C>T and c.421+1G>T) and one known (c.310_311delCT) HPGD mutations. The recurrent mutation c.310_311delCT were found in all eleven patients, suggesting it is a hotspot mutation. PHOAR1 patients are considered to have an autosomal recessive inheritance pattern. Here, in addition to nine compound heterozygous patients and two homozygous patients, we found one heterozygous patient and reviewed two heterozygous patients reported in other studies. In terms of biochemical characteristics, our PHOAR1 patients have elevated urinary prostaglandin E2 (PGE2) levels (P<0.001) and decreased urinary prostaglandin E metabolite (PGE-M) levels (P=0.04) compared with healthy controls. The patients' PGE2/PGE-M (E/M) ratio came out to be lower than normal subjects (P<0.001). This study provides a comprehensive description of the clinical phenotypes of Chinese PHOAR1 patients and expands the genotypic spectrum of the disease.