In reply

We would like to make a contribution toward the recent publication in TRANSFUSION by Mestra and coworkers. Firstly, the authors said that this is the first report of transfusion-transmitted leishmaniasis in an immunocompromised patient in Colombia. However, identification of the Leishmania infection was demonstrated neither in transfused blood components nor in blood donors. Antibodies against Leishmania spp. were detected in the patient’s serum samples as part of a study to rule out renal transplant-transmitted visceral leishmaniasis. However, it is not clear if the serologic Leishmaniapositive result of the patient’s serum corresponded to a sample taken before or after receiving transfusions. To our understanding, if no data related to the patient’s infection status before the transfusions have been clearly provided and, additionally, as Leishmania infection in transfused blood components and/or blood donors has not been demonstrated by the authors, it is very difficult to agree that this certainly represents a case of transfusiontransmitted visceral leishmaniasis. From the transfusion point of view it would have been interesting to know whether or not the transfused blood components were leukoreduced and, if so, when the leukoreduction was performed, that is, before storage or at the bedside, since various studies have been published on the efficacy of whole blood, fresh plasma, and red blood cell filters used for leukoreduction in reducing the number of Leishmania spp. parasites in blood components and thereby minimizing the potential risk of Leishmania transmission through blood transfusions. This information could have thrown light on the probability of the parasite being transmitted to the patient through the transfusion of a contaminated blood component taken from an asymptomatic donor. This case was also published in 2006 as allograft kidney dysfunction associated with infection with amastigotes of Trypanosoma cruzi. However, neither polymerase chain reaction (PCR) nor any other antigen detection technique was performed to demonstrate that the amastigotes in the renal parenchymal corresponded to T. cruzi. To distinguish Chagas disease from Leishmania infection, it would have been helpful to perform Leishmaniaand T. cruzi– specific PCRs on the renal biopsy since it is difficult to differentiate the amastigotes from these two genera by direct microscopic examination. This observation has implications related to the article being commented on because it would explain the patient’s clinical symptoms showing after the renal transplant and immediately before initiating the transfusions. Nifurtimox was given to treat Chagas disease. This may have also contributed to delaying the diagnosis of visceral leishmaniasis, since this medication is partially effective against Leishmania spp. as in vivo studies have shown. All these aspects could also be compatible with the reactivation of a latent Leishmania infection by immunosuppression. We believe that this is a very interesting report concerning a case of visceral leishmaniasis caused by L. (L.) mexicana in an immunocompromised patient in Colombia. This is already in itself a very remarkable contribution made by the authors because, as mentioned in the article, L. (L.) mexicana is a species that has been associated mainly with cutaneous leishmaniasis. There are, however, various aspects that might support the fact that this case was due to the reactivation of a latent Leishmania infection, that is, the patient’s clinical symptoms, the lack of data related to the patient’s infection status before the transfusion, the blood components transfused, and their donors. Similarly, other aspects, which are primarily based on ruling out the transmission of visceral leishmaniasis through solid-organ transplantation, and the fact that the patient’s medical interview did not reveal any prior exposure to Leishmania, all support the hypothesis that the visceral leishmaniasis was transmitted through blood transfusion. Since there are arguments both for and against the two options, we would suggest that this report be considered as a possible case of transfusion-transmitted visceral leishmaniasis.