Changes in Antibody Levels during and following an Episode of Acute Adenolymphangitis (ADL) among Lymphedema Patients in Léogâne, Haiti

INTRODUCTION Episodes of acute adenolymphangitis (ADL) are often the first clinical sign of lymphatic filariasis (LF). They are often accompanied by swelling of the affected limb, inflammation, fever, and general malaise and lead to the progression of lymphedema. Although ADL episodes have been studied for a century or more, questions still remain as to their etiology. We quantified antibody levels to pathogens that potentially contribute to ADL episodes during and after an episode among lymphedema patients in Léogâne, Haiti. We estimated the proportion of ADL episodes hypothesized to be attributed to specific pathogens. METHODS We measured antibody levels to specific pathogens during and following an ADL episode among 41 lymphedema patients enrolled in a cohort study in Léogâne, Haiti. We calculated the absolute and relative changes in antibody levels between the ADL and convalescent time points. We calculated the proportion of episodes that demonstrated a two-fold increase in antibody level for several bacterial, fungal, and filarial pathogens. RESULTS Our results showed the greatest proportion of two-fold changes in antibody levels for the carbohydrate antigen Streptococcus group A, followed by IgG2 responses to a soluble filarial antigen (BpG2), Streptococcal Pyrogenic Exotoxin B, and an antigen for the fungal pathogen Candida. When comparing the median antibody level during the ADL episode to the median antibody level at the convalescent time point, only the antigens for Pseudomonas species (P-value = 0.0351) and Streptolysin O (P-value = 0.0074) showed a significant result. CONCLUSION Although our results are limited by the lack of a control group and few antibody responses, they provide some evidence for infection with Streptococcus A as a potential contributing factor to ADL episodes. Our results add to the current evidence and illustrate the importance of determining the causal role of bacterial and fungal pathogens and immunological antifilarial response in ADL episodes.