| Abstract | We followed 93 subjects with amebic liver abscess (ALA) and 963 close associate controls at 3-month intervals for 36 months to characterize intestinal and humoral antibody responses to the amebic galactose-inhibitable lectin and to determine whether immunity developed to Entamoeba histolytica or Entamoeba dispar infection following cure of ALA. We found that ALA subjects had a higher prevalence and level of intestinal antilectin immunoglobulin A (IgA) and serum anti-LC3 (cysteine-rich recombinant lectin protein) IgA and IgG antibodies, P < 0.01 and P < 0.05, respectively, compared to controls. The intestinal antilectin IgA antibody response was sustained over a longer time period in ALA subjects (71.8% remained positive at 18 months and 52.6% at 36 months, P < 0.001 compared to 17.6% and 10.3% of controls, respectively). ALA subjects were highly immune to E. dispar infection throughout the study (0% infected at 6 and 36 months, compared to 6.5% and 4.9% of control subjects, respectively, P < 0.05). Upon entry into the study, 6.3% of ALA subjects were infected with E. histolytica; the incidence of new E. histolytica infections in controls (as determined by culture) was too low (1.4%) to determine whether ALA subjects exhibited immunity to new infections. We found that stool cultures every 3 months markedly underestimated the occurrence of new E. histolytica infections, as 15.3% of controls seroconverted after 12 months of follow-up. Unfortunately, under the field conditions present in Durban, South Africa, enzyme-linked immunosorbent assay for detection of lectin antigen in stool yielded unreliable results. In summary, subjects cured of ALA exhibited sustained mucosal IgA antibody responses to the amebic galactose-inhibitable lectin and a high level of immunity to E. dispar infection. Determination of immunity to E. histolytica following cure of ALA will require the use of more sensitive and reliable diagnostic methods. |
| Authors | Jonathan I Ravdin, Mohamed D Abd-Alla, Seth L Welles, Selvan Reddy, Terry F H G Jackson
(Affiliation: Department of Medicine, University of Minnesota, Minneapolis, Minnesota 55455, USA. ravdi0001 at umn.edu)
|
| Journal | Infection and immunity
(Infect Immun)
Vol. 71
Issue 12
Pg. 6899-905
(Dec 2003)
ISSN: 0019-9567 United States |
| PMID | 14638778
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)
|
| Chemical References |
- Antibodies, Protozoan
- Immunoglobulin A, Secretory
- Immunoglobulin G
- Lectins
- Membrane Glycoproteins
- Protozoan Proteins
- galactose inhibitable adherence protein, Entamoeba histolytica
|
| Topics |
- Adult
- Animals
- Antibodies, Protozoan
(blood)
- Cohort Studies
- Entamoeba
(immunology)
- Entamoeba histolytica
(immunology)
- Entamoebiasis
(epidemiology, immunology, parasitology)
- Feces
(parasitology)
- Female
- Humans
- Immunoglobulin A, Secretory
(analysis, blood)
- Immunoglobulin G
(blood)
- Intestines
(immunology)
- Lectins
(immunology)
- Liver Abscess, Amebic
(therapy)
- Male
- Membrane Glycoproteins
(immunology)
- Prospective Studies
- Protozoan Proteins
(immunology)
|
