Splenic hypoperfusion as a sign of systemic amyloidosis.

BACKGROUND: The spleen is frequently involved in systemic amyloidosis; however, the computed tomographic (CT) or magnetic resonance (MR) pattern of splenic amyloidosis is not sufficiently described in the literature. This study evaluated the contrast-enhanced CT and MR findings of the spleen in patients with systemic amyloidosis. METHODS: Data were extracted by reviewing pathology and radiology department records of the teaching hospital of Naples over 10 years, from 1 January 1993 to 31 December 2002. Thirty-three patients with amyloidosis were identified, 10 of whom had a CT scan and two of whom had an MR study. The population-based study was composed of 12 patients with histologically proved amyloidosis who underwent contrast-enhanced CT or MR scan of the abdomen. The spleen and liver were evaluated for organ size and perfusion. RESULTS: The spleen was hypoperfused in nine of 12 patients. Mild splenomegaly was present in only one case. Hepatomegaly was associated with markedly acute left lobe margin in nine patients and with rounded anterior profile of segments 3 and 4 in four patients. Moreover, a large area of low attenuation with indefinite geographic margins involving the right hepatic lobe was observed in three patients. CONCLUSION: The finding of splenic hypoperfusion may be a marker of systemic amyloidosis, which represents a useful clue when clinical findings fail to suggest the proper diagnosis.

Endothelin-1 and NO2/NO3 circulating levels after short-term (1h) oxygen supplementation in patients with chronic respiratory failure during long-term oxygen treatment (LTOT).

The effect of acute oxygen administration on endothelin-1 (ET-1) and nitrates (NO.2/NO.3), the latter as stable end products of nitric oxide (NO), were evaluated in arterial and venous blood of chronic respiratory failure (CRF) patients underwent to a continuous long-term oxygen therapy (LTOT). After one hour of oxygen supplementation, ET-1 showed a marked and significant decrease more pronounced in venous blood whereas no statistical change in NO.2/NO.3 concentrations were observed in both arterial and venous blood. There are evidences for increased expression of ET-1 in several pulmonary diseases and for ET-1 plasma reduction in Adult Respiratory Distress Syndrome (ARDS) in patients which recovered. ET-1 is a potent human pulmonary vessel constrictor and may have other effects including plasma exudation, increased mucus secretion and a increased fibrinogenesis. Our data suggest that the improvement in air function, evaluated in part by the decreased release of inflammatory mediators and mainly by reduction in the pulmonary arterial resistance, may be a consequence of the decrease in ET-1 content in the lungs of CRF patients treated with LTOT.