Experimental infection and protection against ... - TI Pharma

Experimental infection and protection against ... - TI Pharma Experimental infection and protection against ... - TI Pharma

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NF135.C10: a new Plasmodium falciparum clone for controlled human malaria infections NF135.C10 Session # mosquitoes offered # mosquitoes with infected bites 1060-09 s1 5 5 total 5 5 1065-10 s1 5 3 s2 2 1 s3 1 1 total 8 5 1083-15 s1 5 4 s2 1 0 s3 1 1 total 7 5 1109-19 s1 5 4 s2 1 1 total 6 5 1114-21 s1 5 4 s2 1 1 total 6 5 NF54 1004-03 s1 5 5 total 5 5 1089-18 s1 5 5 total 5 5 1094-16 s1 5 4 s2 1 1 total 6 5 1095-25 s1 5 5 total 5 5 1100-26 s1 5 5 total 5 5 Supplementary Table 1. Feeding sessions on volunteers by mosquitoes infected with either NF135.C10 or NF54 parasites. Sessions for every individual volunteer are displayed for either NF135.C10 (upper panel) or NF54 (lower panel) groups. Sessions were repeated with a smaller number of mosquitoes until precisely five infected mosquitoes per volunteer had bitten. toxicology and pregnancy. Main exclusion criteria were residence in a malaria endemic area within the previous six months, positive Pf serology [22] or an estimated ten year risk of >5% of developing a cardiac event as estimated by the Systematic Coronary Evaluation system. All volunteers gave written informed consent prior to inclusion. Ten Dutch malaria-naïve volunteers were included and after randomization two groups of five volunteers each were exposed to bites of Anopheles stephensi mosquitoes infected with either NF54 or NF135.C10 for ten minutes at the 133

134 Chapter 7 insectary of the Radboud University Nijmegen Medical Centre. Feeding sessions were repeated when necessary, with a smaller number of mosquitoes until each volunteer had been exposed to exactly five mosquitoes that took a blood meal and had Pf sporozoites in their salivary glands. One feeding session was sufficient for one and four volunteers in the NF135.C10 and NF54 groups respectively, two and one volunteers required two sessions and three feeding sessions were needed in three volunteers of the NF135.C10 group (Supplementary Table 1). Starting from day five post-infection, volunteers were subjected to intensive follow-up with up to thrice daily visits to the LUMC outpatient clinical research department. All signs and symptoms (solicited and unsolicited) were recorded and graded by the attending physician as follows: mild (easily tolerated), moderate (interferes with normal activity), or severe (prevents normal activity), or in case of fever grade 1 (>37.5°C – 38.0°C), grade 2 (>38.0°C – 39.0°C) or grade 3 (>39.0°C). Haematological and biochemical parameters were monitored daily. Because of a previously reported serious cardiac adverse event after a malaria challenge infection in a separate study [23], particular attention was paid to markers of coagulation or cardiac damage with daily follow-up of highly sensitive troponin, platelets, d-dimer and lactate dehydrogenase during the period of expected blood stage parasitemia. Whenever abnormal, blood samples were checked for the presence of fragmentocytes and von Willebrand cleaving protease activity. Promptly after identification of a positive blood smear, volunteers were treated with a curative regimen of four tablets of 250/100mg atovaquone/proguanil once daily for three days. Volunteers whose blood smears remained free of parasites until day 21 after challenge presumptively received the same curative treatment with followup to the end of the study at day 28. Complete cure was always confirmed by two consecutive parasite-negative blood smears. The trial was performed in accordance with Good Clinical Practice and approved by the Central Committee for Research Involving Human Subjects of The Netherlands (CCMO NL30350.058.09). Clinicaltrials.gov identifier: NCT01002833. Parasitological Outcomes Thick blood smears were examined by microscopy twice daily on days five and six post-challenge, thrice daily on days seven to eleven, twice daily on days 12- 15 and once daily on days 16-21 post-challenge. 15µl of EDTA-anti-coagulated blood was spread over the standardised surface of one well of a 3-well glass slide (CEL-LINE Diagnostic Microscope Slides, 30-12A-black-CE24). After drying, wells were stained with Giemsa for 30 minutes. Slides were read at 1000x

NF135.C10: a new Plasmodium falciparum clone for controlled human malaria<br />

<strong>infection</strong>s<br />

NF135.C10<br />

Session<br />

# mosquitoes<br />

offered<br />

# mosquitoes<br />

with infected<br />

bites<br />

1060-09 s1 5 5<br />

total 5 5<br />

1065-10 s1 5 3<br />

s2 2 1<br />

s3 1 1<br />

total 8 5<br />

1083-15 s1 5 4<br />

s2 1 0<br />

s3 1 1<br />

total 7 5<br />

1109-19 s1 5 4<br />

s2 1 1<br />

total 6 5<br />

1114-21 s1 5 4<br />

s2 1 1<br />

total 6 5<br />

NF54<br />

1004-03 s1 5 5<br />

total 5 5<br />

1089-18 s1 5 5<br />

total 5 5<br />

1094-16 s1 5 4<br />

s2 1 1<br />

total 6 5<br />

1095-25 s1 5 5<br />

total 5 5<br />

1100-26 s1 5 5<br />

total 5 5<br />

Supplementary Table 1. Feeding sessions on volunteers by mosquitoes infected<br />

with either NF135.C10 or NF54 parasites. Sessions for every individual volunteer<br />

are displayed for either NF135.C10 (upper panel) or NF54 (lower panel) groups.<br />

Sessions were repeated with a smaller number of mosquitoes until precisely five<br />

infected mosquitoes per volunteer had bitten.<br />

toxicology <strong>and</strong> pregnancy. Main exclusion criteria were residence in a malaria<br />

endemic area within the previous six months, positive Pf serology [22] or an<br />

estimated ten year risk of >5% of developing a cardiac event as estimated by the<br />

Systematic Coronary Evaluation system. All volunteers gave written informed<br />

consent prior to inclusion.<br />

Ten Dutch malaria-naïve volunteers were included <strong>and</strong> after r<strong>and</strong>omization two<br />

groups of five volunteers each were exposed to bites of Anopheles stephensi<br />

mosquitoes infected with either NF54 or NF135.C10 for ten minutes at the<br />

133

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