Tear secretory IgA: evaluation of usefulness as a diagnostic marker in herpetic keratitis

Abstract

In a South Indian study, an 'in-house' enzyme-linked immunosorbent assay (ELISA) was developed to evaluate the potential of herpes simplex virus (HSV)-specific tear secretory IgA (sIgA) in the diagnosis of herpes simplex keratitis (HSK). The presence of HSV-specific tear sIgA was found to be diagnostic in 20.28% of cases. The usefulness of the sIgA ELISA system was evaluated against HSV isolation, which is the 'gold standard' and HSV antigen detection, a more sensitive, commonly employed method. Analysis of HSV-specific IgG and IgM results showed their failure as reliable indicators of active or ongoing infection. Comparison of sIgA ELISA with culture as 'gold standard' showed its sensitivity, specificity, and positive and negative predictive values to be 60% (95% CI 36.4-80), 93.2% (95% CI 86.7-96.8), 60% (95% CI 36.4-80), and 93.2% (95% CI 86.7-96. 8), respectively. This study is the first report on the complete evaluation of the usefulness of tear anti-HSV sIgA in the laboratory diagnosis of HSK, taking into account both epithelial and stromal keratitis cases.

Tear HSV-Specific Secretory IgA as a Potential Indicator for Recurrent Stromal Herpes Simplex Keratitis

“…15 Our results showed that sIgA was positive in 15 of the 41 stromal keratitis patients (36.59%), and 11 of the 15 positive patients (73.3%) also presented with epithelial lesion. In conformity with previous studies, 9 sIgA was not detected in any of the controls, thereby proving its specificity of the assay. Taking together culture/immunofluorescence assay/ IgG along with sIgA, the diagnostic rate of HSK was significantly higher.…”

“…Taking together culture/immunofluorescence assay/ IgG along with sIgA, the diagnostic rate of HSK was significantly higher. 9 This suggests that detection of HSV-specific tear sIgA is an indicator of HSK. One factor that may explain the higher positivity in patients with epithelial lesions is the active viral replication within the epithelium.…”

“…It reaches the maximal concentration in the early stage after onset and could be demonstrated during the first 10 days. 8,9 The aims of our research were to analyze the HSVspecific tear sIgA and its correlation with specific serum antibodies and to evaluate the possible value of specific tear sIgA for prediction of stromal HSK recurrence.…”

Detection of ICP0 protein in tear fluid of individuals with active herpetic epithelial keratitis

“…HSV-1 infectious disease can be diagnosed specifically by the detection of HSV-1 DNA with the use of the polymerase chain reaction [8], of secretory immunoglobulin A in tear fluid [9], or of HSV-1-specific protein with the use of immunofluorescence analysis [10]. Although these methods are reliable, they have certain disadvantages.…”

Influence of Human Immunodeficiency Virus Status on the Clinical History of Herpes simplex Keratitis

“…Tear samples were used for detecting secretory IgA and/or HSV DNA. We have previously [6, 7, 8]reported the details of the prevalence study based on HSV isolation, antigen detection and tear secretory IgA ELISA. Polymerase chain reaction for HSV DNA detection was standardized using a primer sequence against the HSV thymidine kinase gene and the assay was carried out as per the method of Laycock et al [9].…”