Pulmonary involvement in progressive systemic sclerosis: a multidisciplinary approach

Avaliação da tomografia de alta resolução versus radiografia de tórax na doença intersticial pulmonar na esclerose sistêmica

OBJETIVO: Avaliar a acurácia da tomografia de alta resolução (TCAR) do tórax em relação à radiografia simples (RX) do tórax no diagnóstico de doença intersticial pulmonar relacionada à esclerose sistêmica (ES). MATERIAIS E MÉTODOS: Foram realizados TCAR e RX de tórax em póstero-anterior e perfil em 34 pacientes com diagnóstico de ES, segundo critérios do Colégio Americano de Reumatologia, e feita comparação entre as prevalências dos achados radiológicos sugestivos de doença intersticial pulmonar encontradas com estes dois métodos de imagem. RESULTADOS: Foram observadas alterações em 31 (91%) das TCAR, enquanto 16 (47%) dos RX de tórax se apresentavam alterados. Os achados mais freqüentes à TCAR foram: linhas septais (74%), faveolamento (56%) e bandas parenquimatosas (26%), localizados predominantemente nas bases pulmonares. Os RX de tórax demonstraram áreas de infiltrado reticular em 32% dos casos e distorção parenquimatosa em 12% dos pacientes. Em 18 (53%) pacientes com RX de tórax normal a TCAR revelou espessamento septal em 55%, vidro fosco em 44%, faveolamento em 38,5% e cistos em 33%. CONCLUSÃO: A TCAR é mais sensível que o RX de tórax para a investigação de envolvimento intersticial pulmonar inicial em pacientes com ES, justificando, em casos incipientes, tratamento com terapia imunossupressora.

Neuroadrenergic denervation of the lung in type I diabetes mellitus complicated by autonomic neuropathy

STUDY OBJECTIVE

To verify whether autonomic neuropathy (AN) complicating type I, insulin-dependent diabetes mellitus affected neuroadrenergic bronchopulmonary innervation.

PATIENTS

Twenty nonsmoking diabetic patients without respiratory diseases were studied: 11 patients with AN (group AN) and 9 patients without AN (control; group C) diagnosed by standardized criteria.

DESIGN

Patients underwent respiratory function tests and ventilatory scintigraphies with (123)I-metaiodobenzylguanidine (MIBG) and with (99m)Tc-diethylenetriaminepenta-acetic acid (DTPA) to assess both bronchopulmonary neuroadrenergic innervation and also permeability of the alveolar-capillary barrier to water-soluble tracers. Rates of pulmonary clearance of the two tracers were computed, and correlates were identified by nonparametric statistics.

SETTING

University hospital.

RESULTS

The AN and C groups had normal respiratory function test results and comparable duration of diabetes and quality of metabolic control. (99m)Tc-DTPA clearance did not distinguish the groups. (123)I-MIBG clearance was faster in the AN group than in the C group (mean +/- SD half-time of the radiotracer time-activity curve [T(1/2)], 116.1 +/- 22.8 min in the AN group vs 139.5 +/- 18.3 min in the C group, p = 0.022), which is consistent with neuroadrenergic denervation in the AN group. (123)I-MIBG clearance was independent from (99m)Tc-DTPA clearance. Faster (123)I-MIBG clearance was significantly associated with worse performance in three of the four autonomic tests.

CONCLUSIONS

Neuroadrenergic bronchopulmonary denervation may occur in diabetic patients with AN despite normal clinical and respiratory function findings. Further research is needed to identify clinical and prognostic implications of these findings.

Pulmonary function tests in interstitial lung disease: what role do they have?

Pulmonary function tests have been widely accepted and utilized in the management of interstitial lung diseases. Although the tests performed have changed little over the past several decades, extensive literature has been published highlighting their clinical role in the diagnosis, staging, prognostication, and follow-up of patients with a wide variety of interstitial lung diseases.

Manifestations of scleroderma pulmonary disease

Scleroderma is a multisystem disease of unknown cause characterized by synthesis and deposition of excessive extracellular matrix and vascular anti-GBM antibodies, leading to pulmonary hemorrhage and glomerulonephritis with rapidly progressive renal insufficiency. Recent advances in the understanding of disease pathogenesis and diagnosis and treatment have significantly improved our ability to recognize the syndrome, distinguish it from other similar disorders, and offer successful treatment. This article focuses on the pathogenetic features, clinical manifestations, diagnostic strategies, and therapeutic principles of anti-GBM disease.

99mTc SESTAMIBI scintigraphic evaluation of skeletal muscle disease in patients with systemic sclerosis: diagnostic reliability and comparison with cardiac function and perfusion

The diagnosis of skeletal muscle involvement in patients with systemic sclerosis (SSc) is usually based on clinical, laboratory, electromyographic, and bioptic evidence of muscle disorder, whereas SSc cardiac disease is well established by nuclear medicine techniques (radionuclide ventriculography and myocardial scintigraphy). Previous reports have retrospectively hypothesized a possible relationship between cardiac and muscle involvement in scleroderma patients. In order to improve overall diagnostic accuracy in the qualitative/quantitative assessment of skeletal muscle involvement in these patients and to compare these results with those obtained at the cardiac level, diethylenetriaminepentaacetic acid (DTPA)-99mTc radionuclide ventriculography and 99mTc SESTAMIBI myocardial and muscular scintigraphic examinations were performed in 10 SSc patients and in five healthy subjects. Muscular radioactivity, as assessed at thigh and calf levels by means of a segmental score, was significantly decreased in SSc patients in comparison with healthy subjects (global score value 15.6+/-2.2 vs 22.7+/-1.6, p<0.001), as well as right ventricular ejection fraction (RVEF, 34.3%+/-5.3 vs 53.6%+/-4.2, p<0.001) and myocardial segmental perfusion (global score value, 19.6+/-2 vs 25.9+/-1.1, p<0.01). The results show a high frequency of skeletal muscle involvement in patients with SSc. Moreover, scleroderma patients with muscle disorders, as evidenced by scintigraphy, show a comparable occurrence of cardiac involvement, even in the absence of clinical signs of cardiac dysfunction.

Cardiorespiratory responses to incremental exercise in patients with systemic sclerosis

Patients with systemic sclerosis are known to have histologic pulmonary abnormalities despite normal chest radiograph or conventional pulmonary function or both. In an attempt to detect early features of lung involvement in progressive systemic sclerosis, we investigated patients with systemic sclerosis using cardiopulmonary exercise testing. We have studied 78 patients who fulfilled the American Rheumatism Association criteria for the classification of systemic sclerosis, and according to the classification of LeRoy, 44 had limited cutaneous systemic sclerosis and 34 had diffuse cutaneous systemic sclerosis. A significantly decreased diffusing capacity (65 +/- 3% of that predicted) was present only in the group with diffuse cutaneous systemic sclerosis. The patients with lung involvement showed a significant reduction in exercise capacity (54 +/- 3% of that predicted) and in oxygen uptake (70 +/- 3% of that predicted). Additionally, we could demonstrate an increased functional dead space ventilation (0.34 +/- 0.02) and widened alveolar-arterial oxygen difference during exercise (44 +/- 3 mm Hg). By cardiopulmonary exercise testing, 12 of the 78 patients (15%) with normal single-breath diffusing capacity for carbon monoxide had increased dead space to tidal volume ratio. Our results suggest that occult pulmonary impairment may be present in patients with normal pulmonary function and that cardiopulmonary exercise testing enables detection of such impairment. Our study results show the limitations of resting data in predicting abnormalities during exercise in patients with systemic sclerosis.