Progression of interstitial lung disease upon overlapping of systemic sclerosis with polymyositis

Clinical and laboratory features of overlap syndromes of idiopathic inflammatory myopathies associated with systemic lupus erythematosus, systemic sclerosis, or rheumatoid arthritis

Because overlap syndromes (OSs) are rarely described, we analyzed retrospectively their frequencies and correlations in Brazilian series of 31 patients with dermatomyositis (DM)/polymyositis (PM) associated with systemic lupus erythematosus (SLE), systemic sclerosis (SSc), or rheumatoid arthritis (RA) attended at a referral single center. Myositis-specific autoantibodies (MSAs: anti-Jo-1, anti-PL-7, anti-PL-12, anti-EJ, anti-OJ, anti-SRP, anti-Mi-2) and myositis-associated autoantibodies (MAAs: anti-PM-Scl75, anti-PM-Scl100, anti-Ku) as well as specific autoantibodies related to SLE, SSc, and RA were investigated. The mean age of the OS patients (9 DM and 22 PM) was 44.6 ± 15.4 years, with a predominance of women (83.9 %) and white ethnicity (58.1 %). PM was the most frequent inflammatory myopathy, and the clinical presentation of DM/PM was significantly different among the OS groups. Overlap was found with SSc (48.4 %), SLE (29.0 %), and RA (22.6 %). The clinical manifestations of DM/PM were identified simultaneously with SSc and RA in the majority of cases, in contrast to identification in the SLE group (p < 0.05). All patients were positive for antinuclear antibodies, and the prevalence of MSA and MAA was 38.8 % in all OS groups, mutually exclusive, and more frequent in the SSc group. Comparing the clinical and laboratory features, there was a higher frequency of vascular (skin ulcers, Raynaud's phenomenon) and pulmonary (interstitial lung disease) involvement in the SSc group (p < 0.05). Moreover, there were no differences among the groups in relation to disease relapse and deaths. Concluding, this is the first study to show the different characteristics of a series of patients with connective tissue disease (CTD)-OS in the heterogeneous Brazilian population.

Pulmonary Collectins in Diagnosis and Prevention of Lung Diseases

Pulmonary surfactant is a complex mixture of lipids and proteins, and is synthesized and secreted by alveolar type II epithelial cells and bronchiolar Clara cells. It acts to keep alveoli from collapsing during the expiratory phase of the respiratory cycle. After its secretion, lung surfactant forms a lattice structure on the alveolar surface, known as tubular myelin. Surfactant proteins (SP)-A, B, C and D make up to 10% of the total surfactant. SP-B and SPC are relatively small hydrophobic proteins, and are involved in the reduction of surface-tension at the air-liquid interface. SP-A and SP-D, on the other hand, are large oligomeric, hydrophilic proteins that belong to the collagenous Ca²⁺-dependent C-type lectin family (known as “Collectins”), and play an important role in host defense and in the recycling and transport of lung surfactant (Awasthi 2010) (Fig. 43.1). In particular, there is increasing evidence that surfactant-associated proteins A and -D (SP-A and SP-D, respectively) contribute to the host defense against inhaled microorganisms (see 10.1007/978-3-7091-1065_24 and 10.1007/978-3-7091-1065_25). Based on their ability to recognize pathogens and to regulate the host defense, SP-A and SP-D have been recently categorized as “Secretory Pathogen Recognition Receptors”. While SP-A and SP-D were first identified in the lung; the expression of these proteins has also been observed at other mucosal surfaces, such as lacrimal glands, gastrointestinal mucosa, genitourinary epithelium and periodontal surfaces. SP-A is the most prominent among four proteins in the pulmonary surfactant-system. The expression of SP-A is complexly regulated on the transcriptional and the chromosomal level. SP-A is a major player in the pulmonary cytokine-network and moreover has been described to act in the pulmonary host defense. This chapter gives an overview on the understanding of role of SP-A and SP-D in for human pulmonary disorders and points out the importance for pathology-orientated research to further elucidate the role of these molecules in adult lung diseases. As an outlook, it will become an issue of pulmonary pathology which might provide promising perspectives for applications in research, diagnosis and therapy (Awasthi 2010).