Reversal of digital clubbing after lung transplantation in cystic fibrosis patients: a clue to the pathogenesis of clubbing

Elexacaftor-Tezacaftor-Ivacaftor: A Life-Changing Triple Combination of CFTR Modulator Drugs for Cystic Fibrosis

Cystic fibrosis (CF) is a potentially fatal monogenic disease that causes a progressive multisystemic pathology. Over the last decade, the introduction of CF transmembrane conductance regulator (CFTR) modulator drugs into clinical practice has profoundly modified the lives of many people with CF (PwCF) by targeting the fundamental cause of the disease. These drugs consist of the potentiator ivacaftor (VX-770) and the correctors lumacaftor (VX-809), tezacaftor (VX-661), and elexacaftor (VX-445). In particular, the triple combination of CFTR modulators composed of elexacaftor, tezacaftor, and ivacaftor (ETI) represents a life-changing therapy for the majority of PwCF worldwide. A growing number of clinical studies have demonstrated the safety and efficacy of ETI therapy in both short- and long-term (up to two years of follow-up to date) and its ability to significantly reduce pulmonary and gastrointestinal manifestations, sweat chloride concentration, exocrine pancreatic dysfunction, and infertility/subfertility, among other disease signs and symptoms. Nevertheless, ETI therapy-related adverse effects have also been reported, and close monitoring by a multidisciplinary healthcare team remains vital. This review aims to address and discuss the major therapeutic benefits and adverse effects reported by the clinical use of ETI therapy for PwCF.

Can we identify cystic fibrosis from skeletal remains? A proposed differential diagnosis

Cystic fibrosis (CF) is the most common genetic disease within populations with European ancestry and affects approximately 60,000 individuals living in North America and Europe. With recent medical advancement, the life span of CF patients has been extended by decades and bone disease has been observed as a common complication of long-term survivors. In addition to bone disease and associated bone fracturing, living CF patients have a unique etiology of chronic sinusitis, which manifests as a medial bulge in the lateral walls of the nasal aperture, distinct from non-CF chronic sinusitis. We suggest that available data from medical literature is sufficient evidence to indicate that CF can be identified during skeletal analysis, but future work is needed to quantify the sensitivity of the lesions for confirming a CF diagnosis.

Hypertrophic osteoarthropathy: what a rheumatologist should know about this uncommon condition

This article presents an updated overview of hypertrophic osteoarthropathy and digital clubbing for the practicing rheumatologist. Discussion includes a brief historical perspective, its definition, incidence and prevalence, classification, pathology and pathophysiology, clinical manifestations, demographics, findings on physical examination, imaging techniques for its detection, differential diagnosis, and treatment modalities.

Review of current therapies for secondary hypertrophic pulmonary osteoarthropathy

Hypertrophic osteoarthropathy (HOA) is a disabling condition that may occur secondarily to primary lung cancer. It is characterized by digital clubbing, arthralgia/arthritis, and periostosis of the tubular bones. The pain associated with HOA can be disabling and often refractory to conventional analgesics. We performed a comprehensive review of the literature using the PubMed database on treatment modalities available for HOA. We found 52 relevant articles-40 case reports, six case series, two review papers, and four combined case series and review papers. There were no randomized controlled trials reported. We then classified treatments used for HOA into two categories: (1) treatment of primary cause (i.e., resection of tumor, chemotherapy, radiotherapy, treatment of infection, etc.) and (2) symptomatic treatments (i.e., bisphosphonates, octreotide, NSAIDs, vagotomy, etc.). Subsequently, we summarized the main findings for each treatment. Although the clinical diagnosis of HOA has existed for over 100 years, the pathogenesis mechanism has not yet been elucidated, and treatment options for this condition remain experimental. Primary treatment is the most widely reported modality to be efficacious. In cases which primary therapy is not possible, several symptomatic treatment modalities are suggested, with various degree of success. Further research is needed to clarify the pathophysiological mechanism of HOA as to appropriately direct therapy.

Periostitis and hypertrophic pulmonary osteoarthropathy: report of 2 cases and review of the literature

OBJECTIVES

To demonstrate the clinical spectrum of hypertrophic osteoarthropathy (HOA).

METHODS

We report 2 cases of HOA and performed a computer-assisted search of Medline/PubMed for the medical literature from 1960 to June 2008 using the keywords HOA, periostitis, and clubbing. These were also combined with the text words cancer, rheumatic disease, etiology, pathogenesis, hypothesis, transplant, and treatment. Only the English language literature, with pertinent information, was included.

RESULTS

Our 2 cases include 1 HOA case with clubbing, in a patient with a right to left shunt from cryptogenic cirrhosis and interstitial lung disease, and 1 HOA case without apparent clubbing, in a patient with chronic lung transplant rejection secondary to tobacco smoking and related emphysema. Review of the literature has shown that HOA is associated with a wide variety of disorders, approximately 80% are found with primary or metastatic pulmonary malignancies. Various rheumatic diseases, such as systemic vasculitis, can also be associated with HOA. With respect to the pathogenesis, vascular endothelial growth factor, platelet-derived growth factor, and platelets may play crucial roles. Therapeutically, bisphosphonates, such as pamidronade or octreotide, may be tried to relieve symptoms in refractory cases.

CONCLUSIONS

HOA, especially periostitis without clubbing, may go unrecognized. Involvement of vascular endothelial growth factor, platelet-derived growth factor, and platelets in the pathogenesis of HOA has been postulated and supported by recent data. HOA may present as a partial syndrome without clubbing and about 20% of cases have HOA without detectable malignancy. One of our cases represents the first report of the association of HOA with lung transplantation.

Regressão do hipocratismo digital em pacientes com câncer de pulmão tratados cirurgicamente

OBJETIVO: Estudar, por meio de avaliações objetivas, a ocorrência de regressão do hipocratismo digital (HD) em pacientes com câncer de pulmão, tratados cirurgicamente, e revisar a literatura sobre o assunto. MÉTODOS: Sessenta e um pacientes com câncer de pulmão não-pequenas células-40 com e 21 sem HD-foram tratados por cirurgia de ressecção pulmonar. Onze deles (18%) também receberam radioterapia pós-operatória. No período pré-operatório e no 7º, no 18º e no 90º dia pós-operatório, o ângulo hiponiquial (AH) e a relação entre as espessuras falangeana distal e interfalangeana (EFD/EIF) foram determinados sobre imagens da sombra dos dedos indicadores em perfil. Uma revisão da literatura sobre regressão do HD (1954-2007) também foi efetuada. RESULTADOS: Do período pré-operatório ao 90º dia pós-operatório, o AH diminuiu de 200,5 ± 5,0º para 193,3 ± 6,8º (p < 0,001), e a relação EFD/EIF, de 1,014 ± 0,051 mm para 0,956 ± 0,045 mm (p < 0,001) no grupo de 40 pacientes com HD. Em 33 (82,5%), o AH e a relação EFD/EIF diminuíram, mas, em 7 (1,7%), 6 com evolução desfavorável, esses valores não se reduziram. Nos 21 pacientes sem HD, tanto o AH (184,5 ± 5,5º) como a relação EFD/EIF (0,937 ± 0,046 mm) permaneceram inalterados após a cirurgia. Na literatura (1954-2007) foram encontrados 52 casos em que a regressão do HD, observada em diversas condições clínicas, foi explicitamente referida, 5 dos quais eram casos de câncer de pulmão. CONCLUSÕES: O HD em pacientes com câncer de pulmão regride na maioria dos casos após tratamento cirúrgico efetivo do tumor, o que pode também ocorrer em pacientes com outras condições.

Clubbing: an update on diagnosis, differential diagnosis, pathophysiology, and clinical relevance

Finger clubbing can be a striking physical finding. At other times, the presence of clubbing is difficult to establish by subjective examination alone and the profile angle or distal phalangeal to interphalangeal depth ratio are needed to confirm the finding. Most microscopic and imaging studies of clubbed fingers reveal hypervascularization of the distal digits. Recent research shows that when platelet precursors fail to become fragmented into platelets within the pulmonary circulation, they are easily trapped in the peripheral vasculature, releasing platelet-derived growth factor and vascular endothelial growth factor, promoters of vascularity and, ultimately, clubbing. Clinically, clubbing is associated with a number of neoplastic, pulmonary, cardiac, gastrointestinal, infectious, endocrine, psychiatric, and multisystem diseases. In narrowing the differential diagnosis, we recommend a detailed history and physical examination accompanied by focused laboratory and imaging studies. An algorithm for the evaluation of newly diagnosed clubbing is suggested.

Influence of digital clubbing on oxygen saturation measurements by pulse-oximetry in cystic fibrosis patients

OBJECTIVE

To determine the influence of digital clubbing on oxygen saturation by pulse oximetry measurements (SpO2) in Cystic Fibrosis patients.

BACKGROUND

Measuring the arterial oxygen saturation at the fingertip by pulse-oximetry is commonly used in the management of CF patients. In these patients, clinical signs of hyperoxia are often observed with oxygen supplies based on digital oximetry readings. This suggests inaccuracies in the digital measurement method, which in its turn may be caused by digital clubbing. In order to study the influence of digital clubbing, measurements between fingertip and forehead sensor were compared in a clubbing and non-clubbing CF-population. The ear sensor measurements are used as a reference variable.

METHODS

Two groups were examined. Group 1 consisted of 50 CF patients without digital clubbing (DPD/IPD ratio<1.00). Group 2 consisted of 50 CF patients with digital clubbing (DPD/IPD ratio>1.00). Patients were measured at rest before any treatment and with their daily oxygen supply, if applicable. Saturation was simultaneously measured with three Criticare SpO2 T pulse oximeters, using a fingertip sensor at the right index (transmission oximetry), a forehead sensor at the forehead (reflectance oximetry) and an ear sensor at the right ear.

RESULTS

Using the Bland and Altman method no clear difference was found between the saturation measurements of right ear versus forehead sensor in the two groups. When the measurements of right ear versus fingertip sensor are compared there is still no difference for the non-clubbing group. On the contrary, for the clubbing group lower saturation scores were measured by the fingertip probe compared to the right ear measurement. The differences in saturation became greater as the saturation value at fingertip was lower.

CONCLUSION

Digital clubbing significantly influences the registrations of the SpO2 measurements by means of a fingertip probe, underestimating the saturation. It can be advised to use the ear sensor as good alternative for these patients.

Fingernail clubbing and chromonychia associated with the use of angiotensin II receptor blockers

Fingernail clubbing and discoloration frequently indicate serious pulmonary, cardiovascular, and gastrointestinal pathologies. A 76-year-old Caucasian man developed clubbing of the fingernails and discoloration of both the fingernails and toenails after 27 days of treatment with the angiotensin II receptor blocker (ARB) losartan 50 mg/day. Even though this therapy was switched to valsartan, the nail changes persisted for another 6 months. The patient's therapy then was changed to captopril, and the changes gradually subsided over 17 months. An extensive literature search revealed no reports of this effect in association with ARBs. However, one manufacturer had received spontaneous reports. Despite careful consideration of other possible causes of the patient's symptoms, the temporal association with the start and discontinuation of ARB therapy suggests a possible drug-related adverse event.