Digital clubbing

Digital clubbing without hypoxia for lysinuric protein intolerance

Digital clubbing is characterized by bulbous enlargement of the terminal segments of the fingers. Hypotheses including hypoxia have been proposed for the pathogenesis of digital clubbing, but the exact pathogenesis of digital clubbing is still uncertain. Lysinuric protein intolerance (LPI) is caused by pathogenic variants in SLC7A7 and is often associated with interstitial lung disease. Previously two patients of LPI with digital clubbing but without hypoxia have been reported. It is unclear whether digital clubbing in LPI is secondary to hypoxia or directly related to SLC7A7 deficiency. Here we report a 6-year-old Japanese boy presented with digital clubbing without hypoxia. He had episodic vomiting, each episode consisting of a single vomiting event occurring once a month, and his growth had been delayed. He had interstitial lung disease and hepatomegaly. He had compound heterozygous pathogenic variants in the SLC7A7, leading to the diagnosis of LPI. Together with the two previously reported patients mentioned above, we conclude that digital clubbing can occur in the absence of hypoxia. Digital clubbing in the absence of hypoxia has been observed in two genetic disorders related to prostaglandin (PG) E2, HPGD and SLCO2A1. PGE2 synthesis is primarily regulated by the cyclooxygenase 2, which plays a critical role in the control of inflammation. A high urine PGE level in the patient was compatible with the notion that PGE2 production may be increased in LPI. The occurrence of digital clubbing in the absence of hypoxia in LPI patients with SLC7A7 may be attributed to the mechanism of increased PGE2 production.

HIV Versus the Human Body: A Case Report of an Immunity-Compromised Patient

The immune system is the body's defense system against infection, pathogenic organisms, or foreign bodies. Human immunodeficiency virus (HIV) infection significantly reduces the number of cells involved in the immune system making the infected person prone to a greater number of infections like tuberculosis (TB). HIV infection reduces the CD4 T helper cell count and further replicates within the body. HIV-TB is a major health concern as there is more chance of progression to acquired immunodeficiency syndrome (AIDS) and the emergence of drug-resistant TB. In this case report, we see how the HIV-TB infection affects the body, significantly affecting the morbidity and mortality of the patient.

Superficial acral fibromyxoma: insights from case management and comprehensive literature review

Superficial acral fibromyxoma, also known as digital fibromyxoma, is a slow-growing, benign, solitary soft tissue tumor. First described in 2001 by Fetsch et al., it is a condition that often occurs in middle-aged individuals. However, it has also been reported across a wide range of ages, ranging from 4 to 86 years, with males more commonly reported. The condition often presents as solitary soft tissue swelling over the periungual or subungual. We present the management experience of the rare presentation of this rare tumor and a detailed review of the past literature on this condition. Detailed management of the condition has been described, along with the outcome after 2 years of follow-up and treatment experience. Our detailed analysis shows that 2 years is the shortest duration of follow-up to rule out recurrence. Hence, most of the cases reported earlier had given the false sense of the recurrence rate of the tumor, which could lead to undertreatment of the condition. The purpose of this article is to allow the readers to understand better the tumor's characteristics with bone involvement and the tumor's diagnostic strategies and treatment options.

Mathematical models of cystic fibrosis as a systemic disease

Cystic fibrosis (CF) is widely known as a disease of the lung, even though it is in truth a systemic disease, whose symptoms typically manifest in gastrointestinal dysfunction first. CF ultimately impairs not only the pancreas and intestine but also the lungs, gonads, liver, kidneys, bones, and the cardiovascular system. It is caused by one of several mutations in the gene of the epithelial ion channel protein CFTR. Intense research and improved antimicrobial treatments during the past eight decades have steadily increased the predicted life expectancy of a person with CF (pwCF) from a few weeks to over 50 years. Moreover, several drugs ameliorating the sequelae of the disease have become available in recent years, and notable treatments of the root cause of the disease have recently generated substantial improvements in health for some but not all pwCF. Yet, numerous fundamental questions remain unanswered. Complicating CF, for instance in the lung, is the fact that the associated insufficient chloride secretion typically perturbs the electrochemical balance across epithelia and, in the airways, leads to the accumulation of thick, viscous mucus and mucus plaques that cannot be cleared effectively and provide a rich breeding ground for a spectrum of bacterial and fungal communities. The subsequent infections often become chronic and respond poorly to antibiotic treatments, with outcomes sometimes only weakly correlated with the drug susceptibility of the target pathogen. Furthermore, in contrast to rapidly resolved acute infections with a single target pathogen, chronic infections commonly involve multi-species bacterial communities, called "infection microbiomes," that develop their own ecological and evolutionary dynamics. It is presently impossible to devise mathematical models of CF in its entirety, but it is feasible to design models for many of the distinct drivers of the disease. Building upon these growing yet isolated modeling efforts, we discuss in the following the feasibility of a multi-scale modeling framework, known as template-and-anchor modeling, that allows the gradual integration of refined sub-models with different granularity. The article first reviews the most important biomedical aspects of CF and subsequently describes mathematical modeling approaches that already exist or have the potential to deepen our understanding of the multitude aspects of the disease and their interrelationships. The conceptual ideas behind the approaches proposed here do not only pertain to CF but are translatable to other systemic diseases. This article is categorized under: Congenital Diseases > Computational Models.

A case report of an extremely rare association of ankylosing spondylitis with pachydermoperiostosis

Key Clinical Message

We describe a case of a young man with features of pachydermoperiostosis and spondyloarthropathy. By describing this rarity, we aim to help build a database for future studies and construct a management plan that rheumatologists and clinicians can use.

Abstract

This is the first case report in Iraq describing the combination of pachydermoperiostosis and ankylosing spondylitis. We report this interesting association in a 23-year-old male who presented with inflammatory back pain, coarse facial features, clubbing, signs of enthesitis, limitation of spine movement, and clinical and radiographic signs of sacroiliitis.

An Overview of Clinical Manifestations of Dermatological Disorders in Intensive Care Units: What Should Intensivists Be Aware of?

Acute skin failure is rarely the primary diagnosis that necessitates admission to an intensive care unit. Dermatological manifestations in critically ill patients, on the other hand, are relatively common and can be used to make a key diagnosis of an adverse drug reaction or an underlying systemic illness, or they may be caused by factors related to a prolonged stay or invasive procedures. In intensive care units, their classification is based on the aetiopathogenesis of the cutaneous lesion and, in the meantime, distinguishes critical patients. When evaluating dermatological manifestations, several factors must be considered: onset, morphology, distribution, and associated symptoms and signs. This review depicts dermatological signs in critical patients in order to lay out better recognition.

Homozygous Missense Variant in the Solute Carrier Organic Anion Transporter 2A1 (SLCO2A1) Gene Underlies Isolated Nail Clubbing

BACKGROUND

Inherited isolated nail clubbing is a very rare Mendelian condition in humans, characterized by enlargement of the terminal segments of fingers and toes with thickened nails. Mutations in two genes have been reported to cause isolated nail clubbing in humans, which are the SLCO2A1 gene and the HPGD gene.

OBJECTIVES

An extended Pakistani family having two affected siblings born of unaffected consanguineous union was included in the study. Predominant isolated congenital nail clubbing (ICNC) without any other systemic abnormalities was observed, which we aimed to characterize at clinico-genetic level.

METHODS

Whole exome coupled with Sanger sequencing were employed to uncover the sequence variant as a cause of the disease. Furthermore, protein modeling was carried out to reveal the predicted possible effect of the mutation at the protein level.

RESULTS

Whole exome sequencing data analysis revealed a novel biallelic sequence variant (c.155T>A; p.Phe52Tyr) in the SLCO2A1 gene. Further, Sanger sequencing analysis validated and confirmed the segregation of the novel variant in the entire family. Subsequently, protein modeling of the wild-type and mutated SLCO2A1 revealed broad-scale change, which might compromise the proteins' secondary structure and function.

CONCLUSION

The present study adds another mutation to the SLCO2A1-related pathophysiology. The involvement of SLCO2A1 in the pathogenesis of ICNC may open exciting perceptions of this gene in nail development/morphogenesis.

Unilateral digital clubbing in hemiplegia due to a putaminal hemorrhage

Digital clubbing usually occurs bilaterally; however, unilateral clubbing can be seen in hemiplegia and local vascular lesions. We highlight a case of unilateral digital clubbing due to putaminal hemorrhage. Further accumulation of cases will enable exploration of the mechanisms of clubbing.

Computer-Aided Drug Design (CADD) to De-Orphanize Marine Molecules: Finding Potential Therapeutic Agents for Neurodegenerative and Cardiovascular Diseases

Computer-aided drug design (CADD) techniques allow the identification of compounds capable of modulating protein functions in pathogenesis-related pathways, which is a promising line on drug discovery. Marine natural products (MNPs) are considered a rich source of bioactive compounds, as the oceans are home to much of the planet's biodiversity. Biodiversity is directly related to chemodiversity, which can inspire new drug discoveries. Therefore, natural products (NPs) in general, and MNPs in particular, have been used for decades as a source of inspiration for the design of new drugs. However, NPs present both opportunities and challenges. These difficulties can be technical, such as the need to dive or trawl to collect the organisms possessing the compounds, or biological, due to their particular marine habitats and the fact that they can be uncultivable in the laboratory. For all these difficulties, the contributions of CADD can play a very relevant role in simplifying their study, since, for example, no biological sample is needed to carry out an in-silico analysis. Therefore, the amount of natural product that needs to be used in the entire preclinical and clinical study is significantly reduced. Here, we exemplify how this combination between CADD and MNPs can help unlock their therapeutic potential. In this study, using a set of marine invertebrate molecules, we elucidate their possible molecular targets and associated therapeutic potential, establishing a pipeline that can be replicated in future studies.

Canine and Feline Parasitology: Analogies, Differences, and Relevance for Human Health

Cats and dogs are treated as family members by most pet owners. Therefore, a high quality of veterinary care and preventive medicine is imperative for animal health and welfare and for the protection of humans from zoonotic pathogens. There is a general perception of cats being treated as "small dogs," especially in the field of clinical parasitology. As a result, several important differences between the two animal species are not taken into proper consideration and are often overlooked. Dogs and cats are profoundly different under evolutionary, biological, ethological, behavioral, and immunological standpoints. These differences impact clinical features, diagnosis, and control of canine and feline parasites and transmission risk for humans. This review outlines the most common parasitoses and vector-borne diseases of dogs and cats, with a focus on major convergences and divergences, and discusses parasites that have (i) evolved based on different preys for dogs and cats, (ii) adapted due to different immunological or behavioral animal profiles, and (iii) developed more similarities than differences in canine and feline infections and associated diseases. Differences, similarities, and peculiarities of canine and feline parasitology are herein reviewed in three macrosections: (i) carnivorism, vegetarianism, anatomy, genetics, and parasites, (ii) evolutionary adaptation of nematodes, including veterinary reconsideration and zoonotic importance, and (iii) behavior and immune system driving ectoparasites and transmitted diseases. Emphasis is given to provide further steps toward a more accurate evaluation of canine and feline parasitology in a changing world in terms of public health relevance and One Health approach.

Finger clubbing in inflammatory bowel disease: association with upper small bowel lesions and need of surgery in Crohn's disease

OBJECTIVE

Finger clubbing has been associated with inflammatory bowel disease (IBD).

AIMS

In a prospective single-center study, we aimed to assess the frequency of finger clubbing in a cohort of IBD patients. Whether finger clubbing is associated with clinical characteristics of IBD was also investigated.

METHODS

IBD patients with a detailed clinical history were enrolled. Finger clubbing was assessed by visual inspection. Data were expressed as median (range), chi-square, t-test. Multivariate logistic regression analysis was used to assess risk factors for finger clubbing, when considering demographic and clinical characteristics, smoking habits and chronic pulmonary diseases (CPD).

RESULTS

Finger clubbing was searched in 470 IBD patients: 267 Crohn's disease and 203 ulcerative colitis. Finger clubbing was more frequent in Crohn's disease than in ulcerative colitis: 45/267 (16.8%) vs. 15/203 (7.3%) [odds ratio (OR), 2.54 (1.37-4.70); P = 0.003]. Crohn's disease involved the ileum (59.9%), colon (4.5%), ileum-colon (25.8%) and upper gastrointestinal (GI) (9.8%). Ulcerative colitis extent included proctitis (E1) (13.4%), left-sided (E2) (43.3%) and pancolitis (E3) (43.3%). Upper GI lesions, but not other Crohn's disease localizations, were more frequent in patients with finger clubbing [9/45 (20%) vs. 17/222 (7.7%); P = 0.032]. Crohn's disease-related surgery was more frequent in patients with finger clubbing [36/45 (80%) vs. 107/222 (48.1%); P < 0.001]. In Crohn's disease, the only risk factors for finger clubbing were upper GI lesions and Crohn's disease-related surgery [OR, 2.58 (1.03-6.46), P = 0.04; OR, 4.07 (1.86-8.91), P = 0.006]. Ulcerative colitis extent was not associated with finger clubbing [E1: OR, 0.27 (0.02-3.44), P = 0.33; E2: OR, 0.93 (0.24-3.60), P = 0.92; E3:OR, 0.64 (0.22-1.86), P = 0.59]. In ulcerative colitis, but not in Crohn's disease, finger clubbing was more frequent in smokers [13/15 (86.6%) vs. 99/188 (52.6%); P = 0.01] and in patients with CPD [5/15 (33.3%) vs. 16/188 (8.5%); P = 0.002]. Smoking and CPD were the only risk factors for finger clubbing in ulcerative colitis [OR, 7.18 (1.44-35.78), P = 0.01; OR, 10.93 (2.51-47.45), P = 0.001].

CONCLUSION

In the tested IBD population, finger clubbing was more frequent in Crohn's disease than in ulcerative colitis. In Crohn's disease, upper GI lesions and history of Crohn's disease-related surgery were risk factors for finger clubbing, suggesting the possible role of finger clubbing as a subclinical marker of Crohn's disease severity.

Idiopathic pulmonary fibrosis: a more common condition than you may think

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive incurable lung disease that affects a significant amount of people in the UK. Many health professionals have a limited understanding of IPF, which can result in a delayed diagnosis and inadequate care for individuals and their families. This article aims to provide an overview of IPF and help to enhance health professionals' understanding of the disease, thus contributing towards improving the care that IPF sufferers receive. This article provides a definition of IPF and explores its pathophysiology. It discusses the causes and risk factors for developing the condition, examines how IPF is diagnosed and details the treatment options available for IPF patients.

Osteoid osteoma: the great mimicker

Osteoid osteoma is a painful, benign and common bone tumor that is prevalent in young adults. The typical clinical presentation consists of pain that becomes worse at night and is relieved by nonsteroidal anti-inflammatory drugs. The most common imaging finding is a lytic lesion, known as a nidus, with variable intralesional mineralization, accompanied by bone sclerosis, cortical thickening and surrounding bone marrow edema, as well as marked enhancement with intravenous contrast injection. When the lesion is located in typical locations (intracortical bone and the diaphyses of long bones), both characteristic clinical and radiological features are diagnostic. However, osteoid osteoma is a multifaceted pathology that can have unusual presentations, such as intraarticular osteoid osteoma, epiphyseal location, lesions at the extremities and multicentric nidi, and frequently present atypical clinical and radiological manifestations. In addition, many conditions may mimic osteoid osteoma and vice versa, leading to misdiagnosis. Therefore, it is essential to understand these musculoskeletal diseases and their imaging findings to increase diagnostic accuracy, enable early treatment and prevent poor prognosis.

A 58-Year-Old Man with a Painful Gluteal Mass as the First Presentation of Metastatic Adenocarcinoma of the Lung

Patient: Male, 58-year-old

Final Diagnosis: Metastatic lung adenocarcinoma

Symptoms: Gluteal mass

Medication:—

Clinical Procedure: —

Specialty: Oncology • Pulmonology

Sarcoidosis at the Pulmonary Medicine Department of a tertiary care hospital in Mumbai. Our experience and The New Modified Criteria Clinical Radiological Physiological (TNMC CRP) score for sarcoidosis: A novel proposition to assess the functional status

Sarcoidosis is a multisystemic granulomatous disease most commonly involving the pulmonary system and having a myriad of manifestations. However literature is scanty pertaining to the profile and scoring system in sarcoidosis. This study was undertaken to understand the profile of sarcoidosis and an endeavor to assess the functional status with a simplified scoring system. This was an observational study undertaken in the department of Pulmonary Medicine at a tertiary care. The profile of these patients was studied in terms of clinical features, radiological findings, the New Modified Criteria Clinical Radiological Physiological (TNMC CRP) score, six-minute walk distance (6MWD), spirometry, arterial blood gas parameters, serum angiotensin converting enzyme (ACE) levels and tissue biopsy histopathology. The 68 patients included 41 women and 27 men with a mean age of 42.7 years. They comprised of 18 (27%), 39 (57%), 4 (6%), 7 (10%) cases of stage 1, 2, 3, 4 sarcoidosis respectively. Most common presenting symptom and sign was progressive dyspnea 49 (72%), and peripheral lymphadenopathy 15 (22%). Serum ACE was elevated in 57 (83%). The average 6MWD was 360 meters. Most common high resolution computed tomography (HRCT) finding was mediastinal lymphadenopathy and peri-bronchovascular nodules. Spirometry was restrictive abnormality in 48 (96%) patients. Evidence of pulmonary hypertension (PH) was present in 32 (47%) patients. Tissue diagnosis revealed granulomatous inflammation in 51 biopsies with a transbronchial lung biopsy (TBLB) yield of 62%. The average TNMC CRP score was 5. There was a positive correlation between this score and 6MWD which was statistically significant. The score correlated with the functional status. Diagnosis of sarcoidosis warrants a comprehensive and multimodality approach. HRCT and tissue biopsy are the most important diagnostic armamentariums. Modified simplified scores help assess the functional status of the disease.

Clubbed Digits Presumably Caused by Lubiprostone

Digital clubbing has been regarded as an important sign in medicine. A 33-year-old woman with no history of hepatic, pulmonary, or malignant disease was referred to our hospital. She had been taking lubiprostone every day for three years for constipation. Clubbing in her upper and lower limb digits began gradually about two years ago. The results of laboratory investigations were almost normal. We suspected the clubbed digits were a side effect of lubiprostone and confirmed that the levels of urinary prostaglandin E2 (PGE2), which can cause clubbed digits, were elevated. Thus, we instructed the woman to stop taking lubiprostone and monitored this lab value. However, the value continued to rise over 2 months to 41.9 μg/g Cr. During that time, she had been taking sennoside A B calcium instead of lubiprostone for constipation. Since sennoside A B calcium also has the effect of increasing PGE2, we ordered the discontinuation. Her urinary PGE2 to creatinine level normalized, and the clubbing improved after the discontinuation of these two medications.

Whipworm and roundworm infections

Trichuriasis and ascariasis are neglected tropical diseases caused by the gastrointestinal dwelling nematodes Trichuris trichiura (a whipworm) and Ascaris lumbricoides (a roundworm), respectively. Both parasites are staggeringly prevalent, particularly in tropical and subtropical areas, and are associated with substantial morbidity. Infection is initiated by ingestion of infective eggs, which hatch in the intestine. Thereafter, T. trichiura larvae moult within intestinal epithelial cells, with adult worms embedded in a partially intracellular niche in the large intestine, whereas A. lumbricoides larvae penetrate the gut mucosa and migrate through the liver and lungs before returning to the lumen of the small intestine, where adult worms dwell. Both species elicit type 2 anti-parasite immunity. Diagnosis is typically based on clinical presentation (gastrointestinal symptoms and inflammation) and the detection of eggs or parasite DNA in the faeces. Prevention and treatment strategies rely on periodic mass drug administration (generally with albendazole or mebendazole) to at-risk populations and improvements in water, sanitation and hygiene. The effectiveness of drug treatment is very high for A. lumbricoides infections, whereas cure rates for T. trichiura infections are low. Novel anthelminthic drugs are needed, together with vaccine development and tools for diagnosis and assessment of parasite control in the field.

Diagnosis and management of idiopathic pulmonary fibrosis: Thoracic Society of Australia and New Zealand and Lung Foundation Australia position statements summary

INTRODUCTION

Idiopathic pulmonary fibrosis (IPF) is a fibrosing interstitial lung disease associated with debilitating symptoms of dyspnoea and cough, resulting in respiratory failure, impaired quality of life and ultimately death. Diagnosing IPF can be challenging, as it often shares many features with other interstitial lung diseases. In this article, we summarise recent joint position statements on the diagnosis and management of IPF from the Thoracic Society of Australia and New Zealand and Lung Foundation Australia, specifically tailored for physicians across Australia and New Zealand. Main suggestions: A comprehensive multidisciplinary team meeting is suggested to establish a prompt and precise IPF diagnosis. Antifibrotic therapies should be considered to slow disease progression. However, enthusiasm should be tempered by the lack of evidence in many IPF subgroups, particularly the broader disease severity spectrum. Non-pharmacological interventions including pulmonary rehabilitation, supplemental oxygen, appropriate treatment of comorbidities and disease-related symptoms remain crucial to optimal management. Despite recent advances, IPF remains a fatal disease and suitable patients should be referred for lung transplantation assessment.

Clubbing and hypertrophic osteoarthropathy: insights in diagnosis, pathophysiology, and clinical significance

BACKGROUND

Digital clubbing and hypertrophic osteoarthropathy (HOA) form a diagnostic challenge. Subtle presentations of clubbing are often missed. The underlying pathophysiology remains unclear. Establishing a differential diagnosis based on nonspecific signs can be cumbersome. Finally, the prognostic value of clubbing and HOA remains unclear.

OBJECTIVE

This article reviews clinical criteria and pathophysiology of clubbing and HOA. A diagnostic algorithm is proposed, based on etiology and current insights. The prognostic impact on associated diseases is discussed.

METHODS

The Internet databases Medline and Embase were searched. Articles were selected based on relevance of abstract, article type and impact of the journal.

RESULTS

Diagnostic criteria include Lovibond's profile sign, distal/interphalangeal depth ratio and Schamroth's sign. Three pathophysiological causes of clubbing can be distinguished: hypoxia, chronic inflammation and aberrant vascularization. A prominent role for vascular endothelial growth factor is suggested. Associated symptoms and clinical signs should guide the initial diagnostic evaluation. Finally, clubbing is a negative prognostic factor in certain pulmonary disorders, including cystic fibrosis.

[Pulmonary MALT lymphoma and paraneoplastic syndromes]

INTRODUCTION

Primary pulmonary lymphoma is a rare disease; diagnosis is often delayed because of atypical clinical presentation and slow progression.

OBSERVATION

A 42-year-old woman consulted because of haemoptysis. Chest CT-scan showed multiple nodular calcified masses. A lung biopsy led to the diagnosis of pulmonary amyloidosis with pulmonary MALT lymphoma (mucosa-associated lymphoid tissue). The patient developed two paraneoplastic syndromes: a hypertrophic osteoarthropathy and mucinosis.

CONCLUSION

Multiple nodular amyloidosis can be a mode of presentation for pulmonary lymphoma. Paraneoplastic syndromes must be systematically considered and can help in early diagnosis of the disease and its relapse.

A skeletal case of hypertrophic osteoarthropathy from the Canary Islands dating from 1000 BP

A left tibia, the distal right tibia, and the proximal four fifths of the right ulna and radius, probably belonging to an adult prehispanic man (antiquity of ≈1000 years BP) were found among commingled bone remains in a collective burial cave of the island of El Hierro, in the Canary Archipelago. All four bones show an intense periosteal bone formation, encrusting the preserved cortical bone of the diaphyses. Differential diagnosis include melorheostosis, syphilis, and leprosy, although the most likely diagnosis is hypertrophic osteoarthropathy, which is usually associated with lung neoplasm or non-malignant diseases leading to chronic hypoxemia. The marked bone proliferation, possibly due to a chronic condition, suggests that possibly the underlying illness was a non-malignant one.

Small lymphocytic lymphoma with florid perniosis-like features: a case report

BACKGROUND

Small lymphocytic lymphoma is a relatively rare B-cell non-Hodgkin lymphoma that is considered to be the tissue equivalent of the much more common entity chronic lymphocytic leukemia. Cutaneous manifestations of small lymphocytic lymphoma are infrequent and the literature regarding them sparse. We describe here a case of a patient with a history of small lymphocytic lymphoma who developed perniosis-like features of the digits.

CASE PRESENTATION

An 86-year old male patient with previously diagnosed small lymphocytic lymphoma developed painful erythematous swelling of the periungual area of his fingers and toes. This was associated with a dense dermal infiltration of CD5-positive B-lymphoid cells consistent with his low-grade B-cell lymphoma. Although partially refractory to local radiotherapy, the painful swelling of the fingers and toes resolved fully following systemic therapy with chlorambucil and rituximab.

CONCLUSIONS

This unusual cutaneous manifestation of a lymphoma and the favourable response to systemic therapy may be instructive for the management of other patients who develop similar perniosis-like features.

Inactivating mutation in the prostaglandin transporter gene, SLCO2A1, associated with familial digital clubbing, colon neoplasia, and NSAID resistance

HPGDand SLCO2A1 genes encode components of the prostaglandin catabolic pathway, with HPGD encoding the degradative enzyme 15-hydroxyprostaglandin dehydrogenase (15-PGDH), and SLCO2A1 encoding the prostaglandin transporter PGT that brings substrate to 15-PGDH. HPGD-null mice show increased prostaglandin E2 (PGE2), marked susceptibility to developing colon tumors, and resistance to colon tumor prevention by nonsteroidal anti-inflammatory drugs (NSAID). But in humans, HPGD and SLCO2A1 mutations have only been associated with familial digital clubbing. We, here, characterize a family with digital clubbing and early-onset colon neoplasia. Whole-exome sequencing identified a heterozygous nonsense mutation (G104X) in the SLCO2A1 gene segregating in 3 males with digital clubbing. Two of these males further demonstrated notably early-onset colon neoplasia, 1 with an early-onset colon cancer and another with an early-onset sessile serrated colon adenoma. Two females also carried the mutation, and both these women developed sessile serrated colon adenomas without any digital clubbing. Males with clubbing also showed marked elevations in the levels of urinary prostaglandin E2 metabolite, PGE-M, whereas, female mutation carriers were in the normal range. Furthermore, in the male proband, urinary PGE-M remained markedly elevated during NSAID treatment with either celecoxib or sulindac. Thus, in this human kindred, a null SLCO2A1 allele mimics the phenotype of the related HPGD-null mouse, with increased prostaglandin levels that cannot be normalized by NSAID therapy, plus with increased colon neoplasia. The development of early-onset colon neoplasia in male and female human SLCO2A1 mutation carriers suggests that disordered prostaglandin catabolism can mediate inherited susceptibility to colon neoplasia in man.