Parasitic infection with Trichuris trichiura influences plasma levels of soluble HLA class I

High levels of sHLA-I(soluble HLA class 1) have been correlated with rejection episodes in solid organ transport recipients and with graft versus host disease in bone marrow recipients. Studies of human infection with parasitic worms of the gut have suggested that certain individuals may be genetically predisposed to intense infection. In this study, the influence of parasitic helminth infection on levels of sHLA-I in plasma was investigated in 155 HLA typed individuals from St. Lucia exposed to the gut parasite Trichuris trichiura. The results confirmed previous findings showing increased levels of sHLA-I in HLA-A9, and in this case HLA-A23 postive individuals. However, HLA-A9 positive individuals with high worm burden had significantly lower levels of sHLA-I in their plasma compared with HLA-A9 positive subjects with low worm burden. These results suggest that the intensity of T. trichiuria infection infection influences the ability of HLA-A9 positive subjects to maintain high levels of sHLA-I. (AU)

HLA association in Jamaica patients with myasthenia gravis - abstract

Thirty-two (32) Jamaicans with ocular or generalised myasthenia gravis (MG) as well as 40 normal controls were investigated for HLA-A, -B, -C and -DR antigens. HLA antigens contribution to relative risk (RR) in MG patients included HLA -A2 (RR = 615), HLA -B8 (RR = 3.4), HLA-13 (RR=7.76), HLA -DRw8 (RR = 1.34), HLAw12(RR = 1.89), HLA-DQw2(RR = 2.0), HLA -DQw3 (RR = 2.1) and HLA -DRw4 (RR = 3.8). The strongest associations were, therefore, HLA, -A2, -B8, -B13, DQw4. After correction of the 'P value" for the number of antigens tested, only HLA-A2, was significantly increased in MG patients compared to normal Jamaicans. The -DR3 haplo-type which is usually associated with auto-immune diseases was absent in Jamaican MG patients and present in only 5 percent controls. There was a paucity of auto-immune conditions associated with MG in this study. Several of the HLA associations found in Jamaican MG patients correspond to those found in other ethnic groups. However, HLA antigens associated with MG in Jamaican patients were more in agreement with those found in Japanese patients. The HLA types found in Jamaican MG patients did not correlate with thymic pathology, serum concentrations of acetylcholine receptor antibodies, clinical grades or disease course (AU)

Frequency of HLA-A, B and C antigens in Jamaica - abstract

Nothing is known of the frequency of the HLA antigens in the Caribbean. For this reason, HLA-A, B & C typings were performed on a sample of normal individuals in Jamaica in order to obtain these frequencies. Comparisons were then made between the frequencies obtained in the Jamaican study group and the frequencies recorded for other racial groups. HLA-A antigens: The A2 antigens gave the highest frequency (45.2 percent) in the Jamaican study group. In comparing the freqencies of the Jamaican group with frequencies recorded for Europeans, Zambians and Japanese, it was found that the A1 antigen gave highest frequencies amongst the Caucasian and Jamaican groups (15.8 percent and 19.35 percent respectively). The highest frequency recorded in the Zambian group was 27 percent for AW30. The Jamaican group also gave a high frequency for this antigen (19.35 percent). The highest frequency for the Japanese group was for the A9 antigen and here the Jamaican group recorded their second highest frequency (22.5 percent). HLA-B antigens: The highest frequencies obtained for the Jamaican study group were for the HLA BW35, B17 and B12 (35.5 percent, 29 percent and 25.8 percent respectively). The highest frequency recorded for the European group is for the B12 antigen (16.6 percent). The highest frequency for the Zambian is 14.9 percent for B17. However, the Japanese record low frequencies for these groups. The highest frequencies recorded for the Japanese group were 20.9 percent and 21.8 percent for the B5 and B40 antigens respectively. HLA-C antigens: Jamaicans, Zambians and Europeans show their highest frequencies for the CW4 antigen. The cross reactivity of the antigens of the HLA system and the antigenic splits or subgroups confirmed the complexity of the system although in some cases, particularly with the public antigens BW4 and BW6, interpretation of results was aided. The overlap in Jamaican frequencies with frequencies of othe racial groups is probably due to the racial admixture resulting from the intermarriage of the various racial groups in Jamaica (AU)