Prevalence and risk factors of antibodies towards HLA Class I and Class II in Malaysian renal transplant candidates.

Antibody-mediated rejection (AMR) still persists as the major hurdle towards successful renal allograft survival. This paper aims to report on the HLA antibody landscape of renal transplant candidates in Malaysia. A total of 2,219 adult samples from 2016 to 2019 were analysed for anti-HLA antibodies using solid-phase assay. Our findings highlight the prevalence and risk factors for antibodies against HLA antigens in renal transplant settings, which could be beneficial for selecting compatible recipients from deceased organ donors. To the best of our knowledge, this study is the first to demonstrate that ethnic Malay and Chinese showed significantly higher prevalence of anti-HLA antibodies. Based on our multivariate analysis: (i) female gender was associated with higher risk for panel reactive antibodies (PRAs) against Class I, Class II, and Class I and II (p < 0.001); (ii) older patients (≥ 38 years old) were associated with higher risk of positivity against Class I, Class II and Class I and II (p < 0.001); (iii) Malays showed significant association with Class II antibodies (p = 0.035); Chinese patients presented with higher risk of PRA positivity against Class II (p < 0.001) and Class I and II (p = 0.01); Indians were significantly associated with higher risk of HLA antibody sensitization against Class I (p = 0.022), Class II (p = 0.026) and Class I and II (p = 0.05). Thus, our findings suggested that female gender, older age (≥ 38 years old) and ethnicity may serve as independent risk factors for HLA antibody sensitization in adult renal transplant candidates.

Transfer of plastid DNA to the nucleus is elevated during male gametogenesis in tobacco.

In eukaryotes, many genes were transferred to the nucleus from prokaryotic ancestors of the cytoplasmic organelles during endosymbiotic evolution. In plants, the transfer of genetic material from the plastid (chloroplast) and mitochondrion to the nucleus is a continuing process. The cellular location of a kanamycin resistance gene tailored for nuclear expression (35SneoSTLS2) was monitored in the progeny of reciprocal crosses of tobacco (Nicotiana tabacum) in which, at the start of the experiments, the reporter gene was confined either to the male or the female parental plastid genome. Among 146,000 progeny from crosses where the transplastomic parent was male, 13 transposition events were identified, whereas only one atypical transposition was identified in a screen of 273,000 transplastomic ovules. In a second experiment, a transplastomic beta-glucuronidase reporter gene, tailored to be expressed only in the nucleus, showed frequent stochastic expression that was confined to the cytoplasm in the somatic cells of several plant tissues. This gene was stably transferred in two out of 98,000 seedlings derived from a male transplastomic line crossed with a female wild type. These data demonstrate relocation of plastid DNA to the nucleus in both somatic and gametophytic tissue and reveal a large elevation of the frequency of transposition in the male germline. The results suggest a new explanation for the occurrence of uniparental inheritance in eukaryotes.