The autoimmune disease immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) is caused by mutations in the forkhead box protein P3 (FOXP3) gene. In the mouse model of FOXP3 deficiency, the lack of CD4⁺CD25⁺ Tregs is responsible for lethal autoimmunity, indicating that FOXP3 is required for the differentiation of this Treg subset. We show that the number and phenotype of CD4⁺CD25⁺ T cells from IPEX patients are comparable to those of normal donors. CD4⁺CD25^high T cells from IPEX patients who express FOXP3 protein suppressed the in vitro proliferation of effector T cells from normal donors, when activated by “weak” TCR stimuli. In contrast, the suppressive function of CD4⁺CD25^high T cells from IPEX patients who do not express FOXP3 protein was profoundly impaired. Importantly, CD4⁺CD25^high T cells from either FOXP3⁺ or FOXP3^– IPEX patients showed altered suppression toward autologous effector T cells. Interestingly, IL-2 and IFN-γ production by PBMCs from IPEX patients was significantly decreased. These findings indicate that FOXP3 mutations in IPEX patients result in heterogeneous biological abnormalities, leading not necessarily to a lack of differentiation of CD4⁺CD25^high Tregs but rather to a dysfunction in these cells and in effector T cells.

Sperm DNA fragmentation (sDF) represents a threat to male fertility, human reproduction and the health of the offspring. The causes of sDF are still unclear, even if apoptosis, oxidative assault and defects in chromatin maturation are hypothesized. Using multicolor flow cytometry and sperm sorting, we challenged the three hypothesized mechanisms by simultaneously evaluating sDF and signs of oxidative damage (8-hydroxy, 2'-deoxyguanosine [8-OHdG] and malondialdehyde [MDA]), apoptosis (caspase activity and cleaved poly[ADP-ribose] polymerase [cPARP]) and sperm immaturity (creatine phosphokinase [CK] and excess of residual histones). Active caspases and c-PARP were concomitant with sDF in a high percentage of spermatozoa (82.6% ± 9.1% and 53.5% ± 16.4%, respectively). Excess of residual histones was significantly higher in DNA-fragmented sperm versus sperm without DNA fragmentation (74.8% ± 17.5% and 37.3% ± 16.6%, respectively, p < 0.005), and largely concomitant with active caspases. Conversely, oxidative damage was scarcely concomitant with sDF in the total sperm population, at variance with live sperm, where 8-OHdG and MDA were clearly associated to sDF. In addition, most live cells with active caspase also showed 8-OHdG, suggesting activation of apoptotic pathways in oxidative-injured live cells. This is the first investigation on the origin of sDF directly evaluating the simultaneous presence of the signs of the hypothesized mechanisms with DNA breaks at the single cell level. The results indicate that the main pathway leading to sperm DNA breaks is a process of apoptosis, likely triggered by an impairment of chromatin maturation in the testis and by oxidative stress during the transit in the male genital tract. These findings are highly relevant for clinical studies on the effects of drugs on sDF and oxidative stress in infertile men and for the development of new therapeutic strategies.

Objective: To determine the risk factors for and timing of vertical transmission of hepatitis C virus in women who are not infected with HIV-1. Design: Follow up for a median of 28 (range 24-38) months of babies born to women with antibodies to hepatitis C virus but not HIV-1. Subjects: 442 mothers and babies, of whom 403 completed the study. Main outcome measures: Presence of antibodies to hepatitis C virus and viral RNA and alanine aminotransferase activity in babies. Presence of viral RNA, method of infection with hepatitis C, method of delivery, and type of infant feeding in mothers. Results: 13 of the 403 children had acquired hepatitis C virus infection at the end of follow up. All these children were born to women positive for hepatitis C virus RNA; none of the 128 RNA negative mothers passed on the infection (difference 5%, 95% confidence interval 2% to 7%). 6 children had viral RNA immediately after birth. 111 women had used intravenous drugs and 20 had received blood transfusions. 11 of the infected children were born to these women compared with 2 to the 144 with no known risk factor (difference 7%, 2% to 12%). Conclusions: This study suggests that in women not infected with HIV only those with hepatitis C virus RNA are at risk of infecting their babies. Transmission does seem to occur in utero, and the rate of transmission is higher in women who have had blood transfusions or used intravenous drugs than in women with no known risk factor for infection. Key messages: Little information exists on vertical transmission of hepatitis C virus in women not infected with HIV This study in a large unselected population of infants born to HIV-1 negative mothers suggests that intravenous drug use itself is an important risk factor for transmission of hepatitis C virus Maternal post-transfusional hepatitis is also an important risk factor for infection of infants Viral genotype, maternal viraemia, type of delivery (vaginal delivery or caesarean section) and breast feeding do not seem to be risk factors In utero transmission of hepatitis C virus has been suggested by RNA positivity on day of birth in some infected children