Press Release

Wednesday, 07 March 2018

Organ Care System: MHH physicians treat diseased lung outside the body

The growing resistance of pathogens to antibiotics means that, in an increasing number of cases, doctors are out of alternative treatment options for severe pneumonia. Medics at Hannover Medical School (MHH) have, for the first time, used the Organ Care System for successful treatment, outside the body, of pneumonia caused by drug-resistant bacteria. The advantage: when the lung is removed for treatment purposes, physicians can use very high doses of antibiotics that would be toxic to the body, with severe side effects. The scientists published their findings in the journal PLoS One.

In this pilot study, the team led by Professor Axel Haverich, director of the Department of Cardiac, Thoracic, Transplantation and Vascular Surgery (HTTG), looked at whether the treatment of pigs that have severe pneumonia with high-dosage antibiotics in an Organ Care System (OCS) is a suitable new therapy for otherwise incurable drug-resistant lung infections. The investigators treated affected animals with a systemically tolerable dose of the antibiotic colistin and, using the OCS, also treated the explanted diseased lower left lung (LLL) with colistin at 100 times the strength. “Such a dose would not be tolerated by the patient, leading to kidney failure and damage to the central nervous system,” explains Dr Norman Zinne, a specialist at HTTG.

To treat the lung infection outside the body, the doctors first explanted the affected part of the lung and implanted it into an OCS, which is a mobile device for perfusing the lung ex vivo. This system enables donor organs to be transported at body temperature, perfused by donated blood and supplied with nutrients – or, as here, antibiotics. The lung is ventilated during treatment, enabling it to supply itself with oxygen.

After the two-hour procedure, the medics reimplanted the LLL in the animal. “Whereas only one-third of the pigs in the untreated control group and the conventionally treated group survived their pneumonia, two-thirds of the animals whose lungs we treated extracorporeally recovered from the disease,” Dr Zinne says. Furthermore, the clinical symptoms of the infection were less serious in the OCS group than in the other groups. “The results show that treatment of multi-resistant pneumonia using very high-dose antibiotics outside the body constitutes a new therapeutic strategy for severe infections where alternative treatments are now lacking,” adds Professor Haverich. “Before we can apply this method to people we will, for patient safety reasons, first carry out further studies using an animal model,” he stresses. “It is quite conceivable that this approach can be transferred to different organs such as the heart, or to other treatment options such as chemotherapy or cell therapies.”

The antibiotic colistin

Colistin is an antibiotic that has been known since the 1950s but has, since its properties are toxic to the body, hitherto been used only rarely. Due to the emergence of bacteria resistant to antibiotics, colistin has for some time now been seeing increasing use as a reserve antibiotic for treatment of pneumonia caused by the drug-resistant bacterium Pseudomonas aeruginosa.

The project received supported from two sources: the German Centre for Lung Research’s (DZL) local facility BREATH (Biomedical Research in Endstage and Obstructive Lung Disease), funded by Germany’s Federal Ministry of Education and Research (BMBF); and the REBIRTH Cluster of Excellence (REBIRTH: From Regenerative Biology to Reconstructive Therapy), funded by the German Research Foundation (DFG).

Download the press release (in German):
180307_Zinne_OCS.pdf
journals.plos.org/plosone/article