@article{fdi:010075318,
  title = {{T}he separation of trypanosomes from blood by anion exchange chromatography : from {S}heila {L}anham's discovery 50 years ago to a gold standard for sleeping sickness diagnosis},
  author = {{L}ejon, {V}eerle and {B}uscher, {P}. and {N}zoumbou-{B}oko, {R}. and {B}ossard, {G}. and {J}amonneau, {V}incent and {B}ucheton, {B}runo and {T}ruc, {P}hilippe and {L}emesre, {J}ean-{L}oup and {S}olano, {P}hilippe and {V}incendeau, {P}.},
  editor = {},
  language = {{ENG}},
  abstract = {{H}uman {A}frican trypanosomiasis ({HAT}), or sleeping sickness, is a neglected tropical disease that is fatal if untreated, caused by {T}rypanosoma brucei gambiense and {T}. brucei rhodesiense. {I}n its 2012 roadmap, {WHO} targeted {HAT} for elimination as a public health problem in 2020 and for zero transmission in 2030. {D}iagnosis of {HAT} is a multistep procedure comprising of clinical suspicion, confirmation, and stage determination. {S}uspects are identified on clinical signs and/or on screening for specific antibodies. {P}arasitological confirmation of suspects remains mandatory to avoid unnecessary toxic drug administration. {T}he positive predictive value of the antibody detection tests is low. {S}imple parasite detection techniques, microscopic examination of lymph node aspirate, or stained thick blood films lack sensitivity, whereas in {T}. brucei gambiense patients, the number of blood trypanosomes may be very low. {P}arasite concentration techniques are therefore indispensable. {H}alf a century ago, {S}heila {L}anham discovered a technique to separate trypanosomes from the blood of infected rodents, based on anion exchange chromatography with diethyl amino ethyl ({DEAE}) cellulose, a weak anion exchanger. {B}etween p{H} 6-9, trypanosome surface is less negatively charged than that of blood cells. {W}hen blood is poured on top of a {DEAE} cellulose column, blood cells are retained, whereas parasites pass the column together with the elution buffer. {T}he result is a pure suspension of trypanosomes that retain their morphology and infectivity. {B}ecause cell surface charges vary among trypanosome and mammal species, the optimal buffer p{H} and ionic strength conditions for different combinations of host and trypanosome species were established. {L}anham's technique revolutionized the diagnosis of {HAT}. {I}t is indispensable in the production of the {C}ard {A}gglutination {T}est for {T}rypanosomiasis ({CATT}), the most used field test for screening in {T}. brucei gambiense {HAT} foci and essential to confirm the diagnosis in suspected people. {L}umsden and colleagues developed the mini anion exchange centrifugation technique (m{AECT}). {A}fter adaptation for field conditions, its superior diagnostic and analytical sensitivity compared to another concentration technique was demonstrated. {I}t was recommended as the most sensitive test for demonstrating trypanosomes in human blood. {A}t the beginning of the 21st century, the m{AECT} was redesigned, allowing examination of a larger volume of blood, up to 0.35 ml with whole blood and up to 10 ml with buffy coat. {T}he plastic collector tube in the new kit is also used for detection of trypanosomes in the cerebrospinal fluid. {U}nfortunately, m{AECT} also has some disadvantages, including its price, the need to centrifuge the collector tube, and the fact that it is manufactured on a noncommercial basis at only two research institutes. {I}n conclusion, 50 years after {S}heila {L}anham's discovery, {CATT} and m{AECT} have become essential elements in the elimination of {HAT}.},
  keywords = {},
  booktitle = {},
  journal = {{PL}o{S} {N}eglected {T}ropical {D}iseases},
  volume = {13},
  numero = {2},
  pages = {e0007051 [5 p.]},
  ISSN = {1935-2735},
  year = {2019},
  DOI = {10.1371/journal.pntd.0007051},
  URL = {https://www.documentation.ird.fr/hor/fdi:010075318},
}