Granulomatosis with polyangiitis causing subglottic stenosis-two cases and their management.

Granulomatosis with polyangiitis (GPA) is characterised by vasculitis of small and medium sized blood vessels and granulomatous lesions of the respiratory tract. The aetiology is unclear, however it is thought to be due to an autoimmune process with about 92% of patients with the disease being antineutrophilic cytoplasmic antibodies (ANCA) positive. Patients normally present in early adulthood, more commonly in the winter months. Seventy percent of patients with GPA present with ear, nose or throat symptoms. These include nasal congestion, crusting, epistaxis, nasal septal perforation and nasal saddle deformity. Lesions in the airway can lead to subglottic stenosis with resultant airway obstruction. Treatment of the disease complicated by subglottic stenosis is not straightforward and the benefits and risks of options including medical and surgical management need to be weighed up and tailored to each individual case. We describe two cases of GPA complicated by airway obstruction due to subglottic stenosis and their management.

Complement membrane attack complex and hemodynamic changes during human orthotopic liver transplantation.

Hemodynamic changes and elevation of intracellular calcium following reperfusion in human liver transplantation occur rapidly and do not match the time course of cytokine expression, therefore, we postulate involvement of other, pre-formed substances, such as complement. We studied 40 adult patients undergoing liver transplantation. Blood was drawn for estimation of C3, C4, C3 degradation product, membrane attack complex, and CH100 levels and elastase (a marker of neutrophil activation) at induction of anesthesia, 5 minutes before reperfusion, 5 minutes and 60 minutes after reperfusion. Cardiac output was measured by thermodilution and systemic vascular resistance was calculated at these same time points. There was a significant rise in C5b-9 membrane attack complex (P =.0012) with a corresponding fall in C3 (P =.0013) and C4 (P =.0002) levels and a rise in C3 degradation product levels (P =.0006). There was no significant change in CH100. These changes very closely followed the hemodynamic changes of a significant fall in systemic vascular resistance index (P =.0024) and increase in cardiac index (P =.0005). Elastase rose from 356 +/- 53 to 557 +/- 40 microg/L (P <.0001). There is complement activation and neutrophil activation at reperfusion in liver transplantation. Dilution alone cannot explain the fall in C3 and C4 levels as there is a corresponding increase in membrane attack complex and C3 degradation product levels with time. As both C3 and C4 are consumed, the classical pathway must be active, though alternative and lectin activated pathways may also be involved. These findings may, at least in part, explain the hemodynamic changes typically seen at reperfusion in liver transplantation.