Epidemiology and clinical impact of viral, atypical, and fungal respiratory pathogens in symptomatic immunocompromised patients: a two-center study using a multi-parameter customized respiratory Taqman® array card

Pulmonary co-infections by Pneumocystis jirovecii and Herpesviridae: a seven-year retrospective study

BACKGROUND

Pneumocystis jirovecii (P. jirovecii) is an opportunistic fungus responsible for Pneumocystis pneumonia (PCP) in deeply immunocompromised patients and for pulmonary colonization in individuals with mild immunosuppression or impaired respiratory function. PCP and Cytomegalovirus (CMV) co-infections have been widely described whereas those involving other Herpesviruses (HVs) such as Epstein-Barr virus (EBV), Herpes simplex virus type 1 and type 2 (HSV-1 and  -2), and Varicella zoster virus (VZV) remain scarce. To date, no data are available concerning HVs co-infections in P. jirovecii colonization.

METHODS

Our main objective was to evaluate the frequency of HVs in bronchoalveolar lavage fluid (BALF) samples from patients with PCP or with pulmonary colonization. The secondary objective was to assess the relationship between HVs and the mortality rate in PCP patients. A retrospective single-center study over a seven-year period was conducted. All patients with P. jirovecii detected using PCR in a BALF sample and for whom a PCR assay for HVs detection was performed were included in the study.

RESULTS

One hundred and twenty-five patients were included, corresponding to 77 patients with PCP and 48 colonized patients. At least one HV was detected in 54/77 (70.1%) PCP patients and in 28/48 (58.3%) colonized patients. EBV was the most frequent in both groups. Furthermore, the 30-day survival rate in PCP patients was significantly lower with [EBV + CMV] co-infection than that with EBV co-infection, [EBV + HSV-1] co-infection and without HV co-infection.

CONCLUSION

Our results show that the frequency of HV, alone or in combination is similar in PCP and colonization. They also suggest that [EBV + CMV] detection in BALF samples from PCP patients is associated with an increased mortality rate, underlying the significance to detect HVs in the course of PCP.

Design and evaluation of Taqman low density array for monitoring post-transplant viral infections

BACKGROUND

The majority of transplant recipients undergo immunosuppressive treatment to prevent organ or tissue rejection. Consequently, they are more susceptible to infection agents including a number of viruses causing a significant morbidity and mortality. Only a limited number of viruses are currently tested for in transplant donors and recipients due to the cost and complexity. Taqman low density array (TLDA) may provide a suitable format to address more systematic testing approach.

METHODS

One hundred and one liver transplant recipient samples were retrospectively tested for 48 viral targets including two controls (bovine viral diarrhea virus and MS2) and two common viruses (TTV and HPgV), using a custom designed TLDA. Eight samples were analysed simultaneously on 384-well TLDA. Samples giving a signal considered positive/indeterminant were re-tested by different individual confirmatory assays.

RESULTS

Infections with six previously untested for viruses-EBV, HPIV3, HuPuV9, KIV, HMPV and HPV-were detected in fourteen patients. Previously detected HCV infections were also confirmed. These infections did not seem have an effect on 5 year post-transplant outcome. 55 of 79 and 17 of 87 samples available for confirmatory assays were positive for TTV and HPgV, included for the evaluation of the TLDA performance.

CONCLUSIONS

The custom viral TLDA can be successfully used for simultaneous detection of a range of post-transplant viral infections. To fully exploit its potential for monitoring and intervention, a whole blood testing should be applied in a prospective setting.