RHEUMATOLOGY
Rheumatology 2014;53:732736 doi:10.1093/rheumatology/ket419 Advance Access publication 24 December 2013
Concise report Radiological thymus alterations in systemic sclerosis: our experience and a review of the literature Michele Colaci1, Dilia Giuggioli1, Andreina Manfredi1, Caterina Vacchi1, Giovanni Della Casa2 and Clodoveo Ferri1
Objective. Thymus alterations have been related to several autoimmune disorders. In particular, previous studies identified a significant frequency of gland abnormalities by chest high-resolution CT (HRCT) in SSc patients. In this study we aimed to investigate the prevalence of radiological thymic alterations and their correlation with clinical and serological features in a large SSc series. Methods. We retrospectively evaluated thymic shape on CT scans of 200 consecutive, unselected SSc patients aged over 30 years The presence of radiological abnormalities, i.e. enlarged gland >13 mm or nodular lesions >7 mm, was correlated with SSc clinico-serological features. Moreover, the patients were also classified using a second thickness cut-off of 7 mm in order to identify incomplete thymic involution.
CLINICAL SCIENCE
Results. Twenty-four of 200 (12%) SSc patients presented an abnormal thymus at HRCT, including hyperplasic (19/24) and nodular (5/24) glands. Otherwise, using the cut-off of 7 mm for gland thickness and excluding subjects with nodular thymus, 50/195 (25.6%) patients presented an incomplete thymic involution. Thymic radiological alterations are significantly correlated with younger age and diffuse cutaneous SSc. Moreover, an abnormally enlarged thymus tended to be more common in patients with shorter disease duration. Conclusion. The present report on a large series of SSc patients further reinforces previous data present in the literature that includes other cohort studies and a number of anecdotal observations. Even though the actual role of thymus radiological abnormalities remains unclear, possible involvement of the gland in the early phase of immune-mediated SSc pathogenesis might be supposed. Key words: scleroderma, systemic sclerosis, thymus, thymic hyperplasia.
Introduction SSc is an autoimmune disease characterized by endothelial dysfunction and fibrotic tissue overgrowth involving the skin and visceral organs [1]. The aetiology of SSc remains obscure, but a specific role for immunological abnormalities has been raised [1]. The thymus, a primary lymphoid organ, plays a crucial role in immune system homeostasis. In fact, development 1 Rheumatology Unit and 2Radiology Unit, University of Modena and Reggio Emilia, Medical School, Azienda Ospedaliero-Universitaria, Policlinico di Modena, Modena, Italy.
Submitted 21 May 2013; revised version accepted 30 October 2013. Correspondence to: Michele Colaci, Rheumatology Unit, University of Modena & Reggio Emilia, Policlinico di Modena, Via del Pozzo, 71, 41100 Modena, Italy. E-mail: [email protected]
of the functional repertoire of T cells by means of TCR specificity-based selections initiates in the thymus [2]. Autoimmune diseases such as SSc result from a loss of self-tolerance, possibly linked to defects in the thymic epithelial microenvironment [3], therefore thymic disorders might be potentially involved in the pathogenesis of different immune-mediated disorders [3], including SSc. In our preliminary report and in a few other studies [46], this hypothesis has been supported by the observation of thymic morphological alterations at CT evaluation. These findings are in keeping with several anecdotal reports on thymic abnormalities in scleroderma patients [715]. On this basis we further investigated the prevalence of radiological thymic alterations and their correlation with clinical and serological features in a larger SSc series.
! The Author 2013. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: [email protected]
Downloaded from http://rheumatology.oxfordjournals.org/ at University of North Dakota on May 24, 2015
Abstract
Thymic hyperplasia in scleroderma
TABLE 1 Correlation between SSc clinico-serological features and CT alterations of the thymus
All patients 200 57.5 (3087) 5 (038)
Patients with abnormal thymus
176 (88) 59 (3087)
24 (12) 45.5 (3275)
6 (028)
3 (038)
P-value
Patients with thymic hyperplasia
Patients with thymic nodules P-value
Rheumatology 2014;53:732736 doi:10.1093/rheumatology/ket419 Advance Access publication 24 December 2013
Concise report Radiological thymus alterations in systemic sclerosis: our experience and a review of the literature Michele Colaci1, Dilia Giuggioli1, Andreina Manfredi1, Caterina Vacchi1, Giovanni Della Casa2 and Clodoveo Ferri1
Objective. Thymus alterations have been related to several autoimmune disorders. In particular, previous studies identified a significant frequency of gland abnormalities by chest high-resolution CT (HRCT) in SSc patients. In this study we aimed to investigate the prevalence of radiological thymic alterations and their correlation with clinical and serological features in a large SSc series. Methods. We retrospectively evaluated thymic shape on CT scans of 200 consecutive, unselected SSc patients aged over 30 years The presence of radiological abnormalities, i.e. enlarged gland >13 mm or nodular lesions >7 mm, was correlated with SSc clinico-serological features. Moreover, the patients were also classified using a second thickness cut-off of 7 mm in order to identify incomplete thymic involution.
CLINICAL SCIENCE
Results. Twenty-four of 200 (12%) SSc patients presented an abnormal thymus at HRCT, including hyperplasic (19/24) and nodular (5/24) glands. Otherwise, using the cut-off of 7 mm for gland thickness and excluding subjects with nodular thymus, 50/195 (25.6%) patients presented an incomplete thymic involution. Thymic radiological alterations are significantly correlated with younger age and diffuse cutaneous SSc. Moreover, an abnormally enlarged thymus tended to be more common in patients with shorter disease duration. Conclusion. The present report on a large series of SSc patients further reinforces previous data present in the literature that includes other cohort studies and a number of anecdotal observations. Even though the actual role of thymus radiological abnormalities remains unclear, possible involvement of the gland in the early phase of immune-mediated SSc pathogenesis might be supposed. Key words: scleroderma, systemic sclerosis, thymus, thymic hyperplasia.
Introduction SSc is an autoimmune disease characterized by endothelial dysfunction and fibrotic tissue overgrowth involving the skin and visceral organs [1]. The aetiology of SSc remains obscure, but a specific role for immunological abnormalities has been raised [1]. The thymus, a primary lymphoid organ, plays a crucial role in immune system homeostasis. In fact, development 1 Rheumatology Unit and 2Radiology Unit, University of Modena and Reggio Emilia, Medical School, Azienda Ospedaliero-Universitaria, Policlinico di Modena, Modena, Italy.
Submitted 21 May 2013; revised version accepted 30 October 2013. Correspondence to: Michele Colaci, Rheumatology Unit, University of Modena & Reggio Emilia, Policlinico di Modena, Via del Pozzo, 71, 41100 Modena, Italy. E-mail: [email protected]
of the functional repertoire of T cells by means of TCR specificity-based selections initiates in the thymus [2]. Autoimmune diseases such as SSc result from a loss of self-tolerance, possibly linked to defects in the thymic epithelial microenvironment [3], therefore thymic disorders might be potentially involved in the pathogenesis of different immune-mediated disorders [3], including SSc. In our preliminary report and in a few other studies [46], this hypothesis has been supported by the observation of thymic morphological alterations at CT evaluation. These findings are in keeping with several anecdotal reports on thymic abnormalities in scleroderma patients [715]. On this basis we further investigated the prevalence of radiological thymic alterations and their correlation with clinical and serological features in a larger SSc series.
! The Author 2013. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: [email protected]
Downloaded from http://rheumatology.oxfordjournals.org/ at University of North Dakota on May 24, 2015
Abstract
Thymic hyperplasia in scleroderma
TABLE 1 Correlation between SSc clinico-serological features and CT alterations of the thymus
All patients 200 57.5 (3087) 5 (038)
Patients with abnormal thymus
176 (88) 59 (3087)
24 (12) 45.5 (3275)
6 (028)
3 (038)
P-value
Patients with thymic hyperplasia
Patients with thymic nodules P-value
