Rapid Lymphopenia Recovery Predicts Better Outcome

Major Finding: Trauma patients who developed lymphopenia within hours of their injury, followed by recovery of their blood lymphocyte level within 4 days of an injury, had a significantly lower mortality rate, 13%, than did patients who did not have a quick blood lymphocyte recovery (22%) or did not have the early drop in blood lymphocytes (18%).

Data Source: Review of prospectively collected data from 2,448 trauma patients at a U.S. trauma center September 2003-September 2008.

Disclosures: Dr. Heffernan said that he and his associates had no disclosures.

LAS VEGAS — Trauma patients who developed lymphopenia within hours of an injury but recovered their lymphocyte counts over the next 4 days had a better survival rate than patients whose blood lymphocyte levels followed different patterns, a review of more than 2,400 trauma patients treated at one U.S. center found.

“Lymphocytes are not just bystanders following trauma. Persistent lymphopenia [without recovery] was associated with higher mortality and shorter time to death,” Dr. Daithi S. Heffernan said at the annual meeting.

The findings, derived from what he called “the first report detailing the lymphocyte profile in a large trauma population,” suggest that intervention may help patients who fail to recover quickly from lymphopenia. The results also raise the possibility that measuring lymphopenia might be a quick and easy way for physicians to assess trauma patients and predict their acute course.

Dr. Heffernan, a trauma surgeon at Rhode Island Hospital and Brown University, Providence, and his colleagues reviewed data prospectively collected from 2,448 patients seen at the Rhode Island Hospital trauma center from September 2003 to September 2008 who survived for at least 3 days and had an Injury Severity Score (ISS) of at least 15 but not as high as 75. Their average age was 52 years, their average ISS was 23, and their average head Abbreviated Injury Scale (AIS) score was 3.8. Two-thirds of the patients were men.

The researchers divided the patients into three groups: 792 who developed early lymphopenia that resolved back to normal over the first 4 days following injury, 817 patients who developed early lymphopenia that did not resolve during those days, and 839 patients who did not have early lymphopenia. The patients with early lymphopenia that then resolved were significantly younger (average age 46 years) and had higher ISS (average 25) and lower head AIS scores (average 3.5) than did the other patients.

Poorer survival extended not only to patients whose lymphocyte counts failed to recover in 4 days but also to those whose lymphocyte counts never dipped in the hours following traumatic injury. Mortality rates were 13% for patients with early lymphopenia that resolved quickly, 22% for those whose lymphopenia never recovered, and 18% for those who didn't experience lymphocyte declines. The group whose lymphopenia resolved also had a significantly longer time to death than did the other patients.

“I don't think that failure to recover the lymphocyte count is just a marker. It's a contributing factor” to a poor outcome, Dr. Heffernan said. Lymphocyte concentration in blood usually falls after trauma because the cells “are doing their job,” leaving the bloodstream and entering damaged tissues, he explained. The normal response is for these cells to be quickly replaced by new lymphocytes from bone marrow. “If you can't get new cells, you can't fight infection,” Dr. Heffernan said.

“This may help physicians get patients to the ICU earlier. When lymphocyte counts fail to normalize, physicians could know the patient is in trouble.”

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Source Elsevier Global Medical News