The case of a Gaucher disease patient who received a lung transplant to treat pulmonary hypertension calls into question assumptions about how Gaucher affects blood pressure in the lungs, researchers say.
Titled “Lessons from lung transplantation: Cause for redefining the pathophysiology of pulmonary hypertension in gaucher disease,” the case report was published in the journal Respiratory Medicine Case Reports.
Pulmonary hypertension — high blood pressure in the vessels in the lungs — affects as many as a third of people with untreated type 1 Gaucher disease, and around 7% of people on enzyme replacement therapy (ERT).
Although usually mild, the disease can be severe, requiring drastic interventions like transplantation — although lung transplants in Gaucher disease patients have only been described in two other case reports in the existing medical literature.
This case report details the story of a female patient who was diagnosed with Gaucher disease at the age of 14. After diagnosis, treatment included spleen removal, which is noteworthy because pulmonary hypertension in Gaucher disease patients is most common in women who don’t have spleens.
After being diagnosed, the patient was lost to follow-up for some time. Then, at age 33, she presented with shortness of breath and had severe pulmonary hypertension. Treatment with the ERT Cerezyme (imiglucerase), as well as blood thinners and blood pressure medication, initially was helpful. However, the woman’s condition eventually worsened, leading to her being listed for lung transplantation in 2016, when she was 49.
After two years and several additional hospitalizations, a donor was found, and the woman underwent a lung transplant in 2018. The surgery was complicated by significant bleeding, and post-transplant, she required significant lung and kidney support. However, eight months after the transplant, lung function continued to improve.
What was interesting about this case, though, was what was actually going on in the patient’s lungs, which were examined after removal.
Pulmonary hypertension is classified into different types, and pulmonary hypertension in Gaucher disease is usually classified as type 5. That is basically a catch-all category for when there is pulmonary hypertension that doesn’t fit neatly into one of the other four categories. The classical assumption is that such hypertension is caused by the accumulation of Gaucher cells in the lungs, which obstruct blood flow and, in so doing, increase blood pressure.
However, there were hardly any Gaucher cells in the patient’s lungs. Instead, the lungs looked a lot like what happens in pulmonary hypertension type 1, in which the blood vessels in the lungs get too narrow.
This raises the question of whether pulmonary hypertension in people with Gaucher disease has been misclassified. Given the current dearth of studies, however — this made only the third case report in the medical literature — it’s hard to say with certainty how broadly applicable these findings are. The investigators say further research is warranted.