Salivary anti-PGL IgM and IgA titers and serum antibody IgG titers and avidities in leprosy patients and their correlation with time of infection and antigen exposure

Abstract

The present work proposed to correlate serum antibody avidity and salivary antibody titers as parameters for time of infection and antigen exposure in a co-hort study evaluating leprosy patients in different periods of treatment. Colorimetric enzyme-immunoassays for salivary antibodies, serum antibody IgG titers and avidities were performed in the samples. Anti-PGL-1 IgA and IgM salivary antibodies were significantly higher in multibacillar (MB-L) patients compared to normal controls (p<0.05), but not when compared to borderline tuberculoid (BT) or to paucibacillar (PB-L) patients (p>0.05). A good correlation was found between salivary anti-PGL-1 IgA and IgM levels in MB-L patients (r=0.41, p<0.01). Two out of 33 tested saliva samples from patients who had completed the drug regimen treatment presented positive salivary antibodies. Among non-treated patients, samples with low, medium or high serum IgG antibody avidity were found in similar frequencies. In patients under treatment, most of the serum samples showed low or medium IgG antibody avidity. The treated MB-L patients showed medium or high antibody avidity, except for two, who showed very low antibody avidity results. We suggest that salivary anti-PGL antibodies and serum IgG avidity could be useful for the indication of recent exposure or re-exposure to bacteria after chemotherapy.

A role for interleukin‐5 in promoting increased immunoglobulin M at the site of disease in leprosy

“…7 An interesting finding is the differential expression of IgA in L-lep versus T-lep lesions. Anti-M. leprae IgA has been previously reported in salivary secretions of leprosy patients, 32 and the presence of IgA as well as IgG and IgM has previously been identified from induced blisters over skin lesions from patients with L-lep and ENL. 33 Here, we found a correlation of both the messenger RNA and protein levels of IgA, with L-lep versus T-lep directly in skin lesions, suggesting a role for antibodies including promoting progressive infection.…”

The oral cavity in leprosy: what clinicians need to know

“…In addition, it has been shown that MDT seems to reduce anti‐PGL1 antibody levels (Bonfitto et al , ; Rosa et al , ). Similarly, Nagao‐Dias et al () demonstrated that salivary anti‐PGL‐1 IgA and IgM antibodies were significantly higher in MB patients compared with normal controls, but not when compared with PB patients. Moreover, the same authors found a good correlation between salivary anti‐PGL‐1 IgA and IgM levels in MB patients (Nagao‐Dias et al , ).…”

Serum anti‐phenolic glycolipid—1 IgA correlates to IgM isotype in leprosy patients: a possible candidate for seroepidemiological surveys?

“…As it has been shown in previous studies, lipid antigen may elicit ingested by phagocytes. 38 As the presence of anti-PGL1 IgG has been demonstrated in leprosy patients 28 and in contacts, 14 we have decided in the present work to evaluate anti-PGL1 IgA titers.…”

“…Serological analyses for anti‐PGL1 antibodies were performed according to the procedure described elsewhere, with some modifications. Ninety‐six well flat‐bottom microplates (code 3590, Costar, USA) were coated with 5 mg/L of native PGL‐1 in absolute ethyl alcohol (50 μL per well), kindly donated by the Bei Resources/ATCC (Manassas, USA).…”

“…Serological analyses for anti-PGL1 antibodies were performed according to the procedure described elsewhere, 28 with some modifications. The results were expressed in indices according to the following formula: optical density (OD) mean of the test sample (minus blank) divided by the OD mean of the normal human serum pool (minus blank).…”