Laboratory medicine experts and transplant physicians must work closely to identify patients and donors at risk of or harboring bacterial, viral, and parasitic infections, writes Ricardo M. La Hoz, MD, FACP, in the November issue of Clinical Laboratory News (CLN)

In his mini-review of laboratory screening tests performed during pre-transplant evaluations of asymptomatic transplant candidates and donors, La Hoz lists five goals: 

  1. Identify infections that may disqualify the recipient, including latent syphilis and tuberculosis (TB). 
  2. Facilitate transplants from donors infected with certain pathogens such as hepatitis B or C virus or HIV to recipients already infected with those agents. 
  3. Identify and treat active pre-transplant infections. 
  4. Define the risk of infection and determine strategies for preventing or mitigating post-transplant infections. 
  5. Implement prophylactic interventions, including updating vaccination status.

In his mini-review article, La Hoz delves into the many types of infections that require screening, including syphilis, TB, toxoplasmosis, strongyloidiasis, Chagas disease, endemic fungal infections, coccidioidomycosis, HIV, and hepatitis B and C viruses. 

In addition to providing comprehensive information on the screening tests, he highlights the challenges inherent with several. For instance, he writes, a current negative TB test—especially in patients with a well-documented prior positive test—is likely the result of immunosuppression associated with organ failure. Thus, he advises paying particular attention to transplant candidates who have negative results but who are at high risk for post-transplant TB. They may require chemoprophylaxis. 

He also warned that transplant candidates on dialysis may have false negative or false positive results for hepatitis C due to their immunosuppressed states. This is why some transplant centers opt for universal HCV RNA screening for these patients. 

La Hoz also addresses prophylactic strategies to prevent post-transplant infections, such as fluconazole for patients with prior or current coccidioidomycosis, chemoprophylaxis for transplant candidates who have had close contact with someone with active TB or radiographic prior TB (even if their own test is negative), and the importance of updating patient vaccination status. 

Infections remain a major complication of solid organ transplant, he concluded, so screening both donors and recipients is essential to positive clinical outcomes in these life-changing procedures. “For this reason, clinical laboratorians play a key role in the success of transplant programs.” 

Read more in the November issue of CLN.