Line Immunoblot Assay for Tick-Borne Relapsing Fever and Findings in Patient Sera from Australia, Ukraine and the USA.

Ranjan Ramasamy,Jyotsna S Shah,Iris Du Cruz,Akhila Poruri,Rajan Maynard,Stepan Zaporozhan,Ivan Klishch,Raphael B Stricker,Mykhaylo Korda,Song Liu,Mykhaylo Andreychyn,Mariia Shkilna,Kateryna Shtokailo

doi:10.3390/healthcare7040121

Abstract

Tick-borne relapsing fever (TBRF) is caused by spirochete bacteria of the genus Borrelia termed relapsing fever Borreliae (RFB). TBRF shares symptoms with Lyme disease (LD) caused by related Lyme disease Borreliae (LDB). TBRF and LD are transmitted by ticks and occur in overlapping localities worldwide. Serological detection of antibodies used for laboratory confirmation of LD is not established for TBRF. A line immunoblot assay using recombinant proteins from different RFB species, termed TBRF IB, was developed and its diagnostic utility investigated. The TBRF IBs were able to differentiate between antibodies to RFB and LDB and had estimated sensitivity, specificity, and positive and negative predictive values of 70.5%, 99.5%, 97.3%, and 93.4%, respectively, based on results with reference sera from patients known to be positive and negative for TBRF. The use of TBRF IBs and analogous immunoblots for LD to test sera of patients from Australia, Ukraine, and the USA with LD symptoms revealed infection with TBRF alone, LD alone, and both TBRF and LD. Diagnosis by clinical criteria alone can, therefore, underestimate the incidence of TBRF. TBRF IBs will be useful for laboratory confirmation of TBRF and understanding its epidemiology worldwide.

Highlights

Relapsing fever (RF) and Lyme disease (LD) in humans are caused by two related groups of spirochete bacteria of the genus Borrelia known as relapsing fever Borreliae (RFB) and Lyme diseaseBorreliae (LDB), respectively
Possible antigenic cross-reactivity between Lyme disease Borreliae (LDB) and RFB proteins that could give false positive reactions in Tick-borne relapsing fever (TBRF) IBs was investigated with rabbit antisera raised against whole cell lysates of different
The results show that antisera against different LDB species, including two different Borrelia burgdorferi sensu stricto (Bbss) strains B31 and 297, reacted only with the flagellin B (FlaB) derived from RFB and none of the other test RFB antigens in TBRF IBs (Figure 1)

Summary

Introduction

Relapsing fever (RF) and Lyme disease (LD) in humans are caused by two related groups of spirochete bacteria of the genus Borrelia known as relapsing fever Borreliae (RFB) and Lyme disease. Both groups of Borreliae are transmitted by arthropod vectors. New species continue to be discovered and added to the greater than 20 species of Borreliae in each group [1,2]. LD is considered to be the most prevalent tick-borne disease in North America and Western Europe, and the disease has been reported on every continent except Antarctica [1,2,3]. Borrelia bissettii [6] and B. mayonii [7] cause

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Conclusion