Plasma Exchange, Artificial Lung May Boost Survival in Severe AAV
Plasma exchange and extracorporeal membrane oxygenation or ECMO — the use of an artificial lung — are two interventions that may benefit patients with severe ANCA-associated vasculitis (AAV) linked with pulmonary hemorrhage, a potentially life-threatening condition in which blood starts to build up in the lungs, a case study reports.
For a 56-year-old white man in the U.K., such interventions “provided time for life-saving treatments,” his team wrote.
Following nine days on ECMO, the patient “has since made a remarkable recovery,” the researchers wrote.
The study, “Extracorporeal membrane oxygenation for life-threatening ANCA-associated vasculitis with pulmonary haemorrhage,” was published in the journal Rheumatology.
AAV is characterized by inflammation in the blood vessels due to the body’s production of self-reacting antibodies, known as autoantibodies. These antibodies wrongly target and attack a person’s own cells and tissues, leading to blood vessel inflammation and tissue damage.
Plasma exchange is often recommended for people with severe AAV accompanied by respiratory failure due to diffuse alveolar hemorrhage (DAH). This procedure involves removing and replacing a person’s plasma, the liquid portion of blood that contains water, salts, and proteins. This technique can remove certain disease-causing proteins, including anti-neutrophil cytoplasmic autoantibodies, or ANCAs.
However, the usefulness of plasma exchange as a possible treatment for AAV remains controversial.
Now, clinicians at Cambridge University Hospitals, in the U.K., described the case of man admitted to the hospital following three months of experiencing a general feeling of discomfort (malaise), muscle pain, and night sweats. Symptoms were mild and resembled flu, and during this period, the patient made a short trip to Mexico.
Upon returning to the U.K., he developed fever, progressive shortness of breath associated with a dry cough, and the coughing up of blood.
The man’s respiratory rate was greater than normal, a condition called tachypnea, and he had chest crepitations, in which clinicians could hear bubbling or crackling sounds.
Further tests revealed the patient had type 1 respiratory failure, a stage in which oxygen levels are low but carbon dioxide levels remain within the normal range. This type of respiratory failure is often indicative of damage to lung tissue.
Additionally, the patient was diagnosed with severe acute kidney injury, and high levels of inflammation markers, specifically C-reactive protein (CRP). He also was found to have a low number of red blood cells — despite their size remaining normal; this condition is called normocytic anemia.
Despite his urine volume being, at this stage, normal, it contained blood and high levels of albumin, a marker of kidney damage.
Chest CT scans showed the presence of shadows in the lungs, which could have been indicative of pneumonia.
The patient was hospitalized and given intravenous (into-the-vein) antibiotics for presumed atypical pneumonia.
Within one day, however, his respiratory function declined significantly and the patient required oxygen. Further CT scans revealed the accumulation of blood in the lungs, but no blocked artery.
The man was moved to the intensive care unit since he required assistance with a ventilator at maximum capacity, along with renal and heart support.
Even that assistance proved not enough, and the patient was given ECMO, with his blood pumped out of the body into an artificial lung before being infused back into the body.
The patient was maintained on ECMO for nine days. During this period, lab tests confirmed AAV as shown by the abnormally high levels of autoantibodies targeting proteinase 3 (PR3).
At that point, he then was given into-the-vein methylprednisolone followed by oral prednisolone.
Once his respiratory parameters stabilized, he enrolled in the Phase 3 PEXIVAS trial (NCT00987389), a study assessing the effectiveness of plasma exchange and glucocorticoid therapy in patients with ANCA-associated vasculitis.
The patient received seven sessions of plasma exchange in addition to into-the-vein cyclophosphamide, given over three months, followed by oral immunosuppressive treatment with azathioprine. During this period, he underwent a gradual weaning of oral prednisolone. Due to a mild intolerance to azathioprine, this medication was replaced by mycophenolate mofetil.
The patient had a long period of rehabilitation, which was complicated by critical muscle disease (myopathy) and periods of delirium. However, his recovery was “remarkable,” according to the team wrote.
He didn’t depend on dialysis and remained in remission for a long period without any respiratory sequelae and restrictions on exercise.
Overall, “plasma exchange remains an intervention that should be considered in patients with respiratory failure secondary to ANCA-associated pulmonary haemorrhage,” the researchers wrote.
“ECMO may also be life-saving in patients with life-threatening ANCA-associated pulmonary haemorrhage,” they added. “The key role of ECMO in this case is that it provided time for life-saving treatments to be instituted.”
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