Sustained low diffusing capacity in hepatopulmonary syndrome after liver transplantation

AIM： To study the presence of sustained low diffusing capacity （DLco） after liver transplantation （LT） in patients with hepatopulmonary syndrome （HPS）. METHODS： Six patients with mild-to-severe HPS and 24 without HPS who underwent LT were prospectively followed before and after LT at mid-term （median, 15 mo）. HPS patients were also assessed at Iong-tem （median, 86 mo）. RESULTS： Before LT, HPS patients showed lower PaO2 （71 ± 8 mmHg）, higher AaPO2 （43 ± 10 mmHg） and lower DLco （54% ± 9% predicted）, due to a combination of moderate-to-severe ventilation-perfusion （VA/Q） imbalance, mild shunt and diffusion limitation, than non- HPS patients （94 ± 4 mmHg and 19 ± 3 mmHg, and 85% ± 3% predicted, respectively） （P 〈 0.05 each）. Seven non-HPS patients had also reduced DLco （70% ± 4% predicted）. At mid- and long-term after LT, compared to pre- LT, HPS patients normalized PaO2 （91 ± 3 mmHg and 87 ± 5 mmHg）, AaPO2 （14 ± 3 mmHg and 23 ± 5 mmHg） and all VA/Q descriptors （P 〈 0.05 each） without changes in DLco （53% ± 8% and 56% ± 7% predicted, respectively）. Post-LT DLco in non-HPS patients with pre- LT low DLco was unchanged （75% ± 6% predicted）. CONCLUSION： While complete VA/Q resolution in HPS indicates a reversible functional disturbance, sustained low DLco after LT also present in some non-HPS patients, points to persistence of sub-clinical liver-induced pulmonary vascular changes.

Whole Lung Lavage Treatment of Chinese Patients with Autoimmune Pulmonary Alveolar Proteinosis： A Retrospective Long-term Follow-up Study

Background： Pulmonary alveolar proteinosis （PAP） is a rare lung disease, the most common type of which is autoimmune PAP. The gold standard therapy for PAP is whole lung lavage （WLL）. Few studies have reported the optimal technique with which to evaluate the response to WLL. In this study, we aimed to identify parameters with which to assess the need for repeat WLL during a long-term 8-year follow-up. Methods： We conducted a retrospective analysis of 120 patients with autoimmune PAP with 80 of whom underwent WLL. Physiologic, serologic, and radiologic features of the patients were analyzed during an 8-year follow-up after the first WLL treatment. Results： Of the 40 patients without any intervention, 39 patients either achieved remission or remained stable and only one died of pulmonary infection. Of the 56 patients who underwent WLL for 1 time, 55 remained free from a second WLL and 1 patient died of cancer. Twenty-four required additional treatments after their first WLL. The baseline PaO2, （P = 0.000）, PA-aO2 （P = 0.000）, shunt fraction rate （P = 0.001）, percent of predicted normal diffusing capacity of the lung for carbon monoxide （DLCO%Pred） （P = 0.016）, 6-rain walk test （P = 0.013）, carcinoembryonic antigen （CEA） （P = 0.007）, and neuron-specific enolase （NSE） （P = 0.003） showed significant differences among the three groups. The need for a second WLL was significantly associated with PaO2 （P = 0.000）, CEA （P= 0.050）, the 6-minute walk test （P= 0.026）, and DLCO%Pred （P = 0.041 ）. The DLCO%Pred on admission with a cut-off value of42.1% （P = 0.001） may help to distinguish whether patients with PAP require a second WLL. Conclusions： WLL is the optimal treatment method for PAP and provides remarkable improvements for affected patients. The DLCO%Pred on admission with a cut-offvalue of 42.1% may distinguish whether patients with PAP require a second WLL.