Morphological and Transcriptional Changes in Human Bone Marrow During Natural Plasmodium vivax Malaria Infections.

18 Jun 2020
Brito MAM, Baro B, Raiol TC, Ayllon-Hermida A, Safe IP, Deroost K, Figueiredo EFG, Costa AG, Armengol MDP, Sumoy L, Almeida ACG, Hounkpe BW, De Paula EV, Fernandez-Becerra C, Monteiro WM, Del Portillo HA, Lacerda MVG

BACKGROUND

The presence of Plasmodium vivax malaria parasites in the human bone marrow (BM) is still controversial. However, recent data from a clinical case and experimental infections in splenectomized nonhuman primates unequivocally demonstrated the presence of parasites in this tissue.

METHODS

In the current study, we analyzed BM aspirates of 7 patients during the acute attack and 42 days after drug treatment. RNA extracted from CD71+ cell suspensions was used for sequencing and transcriptomic analysis.

RESULTS

We demonstrated the presence of parasites in all patients during acute infections. To provide further insights, we purified CD71+ BM cells and demonstrated dyserythropoiesis and inefficient erythropoiesis in all patients. In addition, RNA sequencing from 3 patients showed that genes related to erythroid maturation were down-regulated during acute infections, whereas immune response genes were up-regulated.

CONCLUSIONS

This study thus shows that during P. vivax infections, parasites are always present in the BM and that such infections induced dyserythropoiesis and ineffective erythropoiesis. Moreover, infections induce transcriptional changes associated with such altered erythropoietic response, thus highlighting the importance of this hidden niche during natural infections.