The first autopsy performed on a victim of Middle East respiratory syndrome (MERS) has shown the extent of the infection’s impact on the lungs and lower respiratory tract. 

The post-mortem examination — on a 45-year-old man who died of MERS at a hospital in the United Arab Emirates — yields new insights into how the coronavirus responsible for the disease attacks the body, and offers clues for how to treat the illness. 

“This investigation can be used for a host of applications ranging from diagnosis and prevention, to treatment and determination of pathogenesis,” says Sherif Zaki, chief of the Infectious Diseases Pathology Branch at the US Centers for Disease Control and Prevention.  

MERS was first identified in Saudi Arabia in 2012 and has since spread throughout the Arabian Peninsula and into 27 countries worldwide. Of the 1,700-plus confirmed cases, more than a third have died. Yet, it wasn’t until earlier this year that pathologists described the first autopsy on a MERS victim, outlining the microscopic details of diseased tissues that help explain how the infection kills. 

Zaki led the team that performed the autopsy in April 2014, ten days after the patient died. They documented widespread damage to the air sacs of the lungs and lower airways. Staining assays showed that the MERS coronavirus targeted cells in these damaged regions, but not other tissues outside the respiratory tract. 

The infected cells expressed a protein on their surface called dipeptidyl peptidase 4, or DPP4, supporting earlier evidence from lab experiments that the MERS coronavirus hijacks this protein to enter and infect cells. “This implies,” says Zaki, “that DPP4 inhibitors could have therapeutic value,” although more research is needed to confirm the potential of this drug target. 

Some doctors had previously suggested the MERS coronavirus might infect the kidneys. But, no virus was detected in the kidneys in the post-mortem exam. Zaki suspects that any kidney damage associated with MERS is not due to direct viral attack in these organs, but a consequence of general immune dysfunction following lung infection. 

“One must be cautious when analyzing and making recommendations from the findings of a single autopsy report,” Zaki says. And “much more data is needed from studies of other infected MERS patients [and mortalities] to better understand the pathogenesis and optimal treatment for these patients.” But, he adds, this first autopsy does provide “critical insights” into this new and emerging infectious disease.

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