Identification and specificity of a 38�kDa Loa loa antigenic fraction in sera from high-microfilaraemic Gabonese patients

Walker-Deemin, A.; Ferrer, Adelaida; Gauthier, France; Kombila, Maryvonne; Richard-Lenoble, D

doi:10.1007/s00436-003-1024-1

Cited by 9 publications

(6 citation statements)

References 20 publications

(14 reference statements)

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“…Loa loa -specific antibodies were detected in serum samples from patients by indirect immunofluorescence (IIF) with homologous antigens from L. loa microfilariae prepared in the department, as described elsewhere (Walker-Deemin et al , 2004). The antibody– L. loa specificity threshold was a titre above 1:200.…”

Section: Methodsmentioning

confidence: 99%

The relationship between microfilaraemic and amicrofilaraemic loiasis involving co-infection with Mansonella perstans and clinical symptoms in an exposed population from Gabon

et al. 2015

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The relationship between the frequency of loiasis objective symptoms and microfilaraemic or amicrofilaraemic infection was assessed in 1148 exposed patients also infected, or not, with Mansonella perstans. Filarial infections were detected by direct microscopy, leucoconcentration and serology, with prevalence values of 39.5% Loa loa, 5.6% M. perstans and 3.4% co-infection with both filarial species. Amicrofilaraemic or occult loiasis (OL) predominated among L. loa-infected individuals, with a prevalence of 58.2%. Hypermicrofilaraemia (>8000 microfilariae (mf)/ml) was found in 18.4% of L. loa microfilaraemic patients, with 25.7% of them harbouring more than 30,000 mf/ml. Up to 34% of patients with OL showed evidence of Calabar swelling, compared with 26.3% of microfilaraemic patients (P= 0.03). Overall 5.3% of patients presented with adult worm migration across the eye, representing 16.3% of microfilaraemic individuals and 11.4% of amicrofilaraemic patients (P= 0.13). This symptom was similarly found in patients with more than 30,000 mf/ml (22%), those with microfilaraemia between 8 and 30,000 mf/ml (15.4%) and also in individuals with low or without microfilaraemia (16.1%) (P= 0.7). Five (14.3%) hypermicrofilaraemic patients did not present any L. loa-specific objective symptoms, as well as all the patients with single M. perstans infection. The presence of adult eye worm migration as a strong predictor of high microfilaraemia density would obscure the real burden of L. loa hypermicrofilaraemia in exposed individuals. For epidemiological purposes and control strategies, the mapping of L. loa in endemic areas should also take into account the group of patients with occult loiasis.

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Section: Methodsmentioning

confidence: 99%

The relationship between microfilaraemic and amicrofilaraemic loiasis involving co-infection with Mansonella perstans and clinical symptoms in an exposed population from Gabon

et al. 2015

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“…The measurement of Loaspecific IgG 4 in an ELISA may be used to detect an occult infection (Akué et al, 1994) but this technique is not very sensitive (Touré et al, 1999a;Klion et al, 2003). Although circulating Loa antigens have been detected in some patients, no diagnostic tests based on antigen detection are currently available (Walker-Deemin et al, 2004). The best technique currently available for the diagnosis of loiasis, especially occult infection, is based on a PCR for the detection of the species-specific sequences of the repeat-3 region of the gene encoding a 15-kDa protein (Touré et al, 1997(Touré et al, , 1998.…”

Section: Diagnosismentioning

confidence: 99%

Loiasis

Boussinesq

2006

Annals of Tropical Medicine & Parasitology

175

145

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Loiasis affects millions of individuals living in the forest and savannah regions of Central Africa. In some areas, this disease constitutes one of the most common reasons for medical consultation. The burden posed by loiasis is probably under-estimated and, in addition, individuals harbouring high Loa microfilarial loads are at risk of developing serious neurological reactions after treatment with diethylcarbamazine or ivermectin. These events are currently significantly hampering the development of the African Programme for Onchocerciasis Control, and operational research is required to address the issue. The results of recent studies, involving either human populations from endemic areas or monkey models, have provided much more detail of the mechanisms associated with amicrofilaraemic or so-called 'occult' loiasis. New diagnostic tools have also been developed in the last decade, and various protocols are now available for the risk-free treatment of loiasis cases.

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“…Several prior studies have reported circulating L . loa antigens in the blood [32–34] and urine [35] of persons with loiasis. Our study differed in that we sought to specifically capture the antigens responsible for W .…”

Section: Discussionmentioning

confidence: 99%

Identification and characterization of Loa loa antigens responsible for cross-reactivity with rapid diagnostic tests for lymphatic filariasis

Hertz

Nana-Djeunga²,

Kamgno

et al. 2018

PLoS Negl Trop Dis

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The Global Program to Eliminate Lymphatic Filariasis (LF) relies on rapid diagnostic tests (RDTs) to determine where annual mass drug administration for LF is required and when it can be stopped. These tests detect a Wuchereria bancrofti glycoprotein in the blood of infected persons via a carbohydrate moiety recognized by the monoclonal antibodies AD12 and DH6.5. Loiasis cross-reactivity with LF RDTs has recently been recognized as a serious obstacle to LF elimination in loiasis-endemic areas. To better understand the nature of this cross-reactivity, we used the DH6.5 antibody to immunoaffinity purify Loa loa antigens from the sera of individuals with a positive RDT due to loiasis. Immunoblot analysis revealed many circulating AD12/DH6.5-reactive antigens, and proteomic analysis identified multiple L. loa proteins in LF RDT-positive loiasis sera. These included both secreted and somatic proteins, suggesting that they may be released by dying L. loa adult worms and/or microfilariae. Unlike the single high molecular weight W. bancrofti circulating filarial antigen that is reliably present in the blood of persons with bancroftian filariasis, reactive L. loa antigens appeared to be only transiently present in the blood of a subset of persons with loiasis. These key differences between the circulating antigens of W. bancrofti and L. loa can be used to differentiate positive results generated by both species and may lead to improved diagnostic tests for LF and loiasis.

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Identification and specificity of a 38�kDa Loa loa antigenic fraction in sera from high-microfilaraemic Gabonese patients

Cited by 9 publications

References 20 publications

The relationship between microfilaraemic and amicrofilaraemic loiasis involving co-infection with Mansonella perstans and clinical symptoms in an exposed population from Gabon

The relationship between microfilaraemic and amicrofilaraemic loiasis involving co-infection with Mansonella perstans and clinical symptoms in an exposed population from Gabon

Loiasis

Identification and characterization of Loa loa antigens responsible for cross-reactivity with rapid diagnostic tests for lymphatic filariasis

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