Article
Recombinant protein KR95 as an alternative for serological diagnosis of human visceral leishmaniasis in the Americas
Registro en:
FUJIMORI, Mahyumi et al. Recombinant protein KR95 as an alternative for serological diagnosis of human visceral leishmaniasis in the Americas. Plos One, v. 18, n. 3, e0282483, Mar. 2023.
1932-6203
10.1371/journal. pone.0282483
Autor
Fujimori, Mahyumi
Valencia-Portillo, Ruth Tamara
Lindoso, Jose´ Angelo Lauletta
Celeste, Beatriz Julieta
Almeida, Roque Pacheco de
Costa, Carlos Henrique Nery
Cruz, Alda Maria da
Druzian, Angelita Fernandes
Duthie, Malcolm Scott
Fortaleza, Carlos Magno Castelo Branco
Oliveira, Ana Lúcia Lyrio de
Paniago, Anamaria Mello Miranda
Queiroz, Igor Thiago
Reed, Steve
Vallur, Aarthy C.
Goto, Hiro
Sanchez, Maria Carmen Arroyo
Resumen
In the Americas, visceral leishmaniasis (VL) is caused by the protozoan Leishmania infantum,
leading to death if not promptly diagnosed and treated. In Brazil, the disease reaches
all regions, and in 2020, 1,933 VL cases were reported with 9.5% lethality. Thus, an accurate
diagnosis is essential to provide the appropriate treatment. Serological VL diagnosis is
based mainly on immunochromatographic tests, but their performance may vary by location,
and evaluation of diagnostic alternatives is necessary. In this study, we aimed to evaluate
the performance of ELISA with the scantily studied recombinant antigens, K18 and KR95,
comparing their performance with the already known rK28 and rK39. Sera from parasitologically
confirmed symptomatic VL patients (n = 90) and healthy endemic controls (n = 90)
were submitted to ELISA with rK18 and rKR95. Sensitivity (95% CI) was, respectively,
83.3% (74.2–89.7) and 95.6% (88.8–98.6), and specificity (95% CI) was 93.3% (85.9–97.2)
and 97.8% (91.8–99.9). For validation of ELISA with the recombinant antigens, we included
samples from 122 VL patients and 83 healthy controls collected in three regions in Brazil
(Northeast, Southeast, and Midwest). When comparing the results obtained with the VL
patients’ samples, significantly lower sensitivity was obtained by rK18-ELISA (88.5%, 95%
CI: 81.5–93.2) compared with rK28-ELISA (95.9%, 95% CI: 90.5–98.5), but the sensitivity was similar comparing rKR95-ELISA (95.1%, 95% CI: 89.5–98.0), rK28-ELISA (95.9%,
95% CI: 90.5–98.5), and rK39-ELISA (94.3%, 95% CI: 88.4–97.4). Analyzing the specificity,
it was lowest with rK18-ELISA (62.7%, 95% CI: 51.9–72.3) with 83 healthy control samples.
Conversely, higher and similar specificity was obtained by rKR95-ELISA (96.4%, 95% CI:
89.5–99.2), rK28-ELISA (95.2%, 95% CI: 87.9–98.5), and rK39-ELISA (95.2%, 95% CI:
87.9–98.5). There was no difference in sensitivity and specificity across localities. Crossreactivity
assessment, performed with sera of patients diagnosed with inflammatory disorders
and other infectious diseases, was 34.2% with rK18-ELISA and 3.1% with rKR95-
ELISA. Based on these data, we suggest using recombinant antigen KR95 in serological
assays for VL diagnosis.