Utility and importance of accurate Hb A2 measurements for defining a strategy for ß-thalassemia screening: experience in the Balearic Islands, Spain.

The high heterogeneity in regional profiles of ß-thalassemia (ß-thal) mutations highlights the need for population-specific carrier detection strategies. Our aim was to analyze the relationship between hematological values and ß(0) and ß(+) mutations in 154 Balearic ß-thal heterozygotes, in order to establish the most optimized mutation carrier detection strategy to be used to manage the disease in our population. The Hb A2 level was the best parameter for discriminating between both types of carriers. Taking into account the cut-off point value of 4.85% (Hb A2), obtained by a receiver-operating characteristic (ROC) curve analysis, we proposed an algorithm that would use a real-time polymerase chain reaction (RT-PCR) hybridization probe assay technique to detect one of the two most common mutations in the Balearic population, namely codon 39 (C>T) and IVS-I-110 (G>A), depending on the Hb A2 value of the patient.

Effect of co-inheritance of ß-thalassemia and hemochromatosis mutations on iron overload.

Co-inheritance of mutations in the HFE gene underlying hereditary hemocromatosis (HH) may play a role in the variability of iron status in patients with ß-thalassemia (ß-thal) minor. Different studies have yielded conflicting results: some suggest iron overload might arise from the interaction of the ß-thal trait with homozygosity or even heterozygosity for HFE mutations and others that it was unrelated to the HFE genotype. Because of the high frequency of HFE mutations in the Balearic Islands, where the ß-thal trait is also moderately common, it is of interest to evaluate the effect of the co-inheritance of mutations in both genes on the severity of iron loading. A retrospective analysis of 142 individuals heterozygous for ß-thal was performed to investigate the effect of HFE mutations on iron status of these patients. No significant differences were detected between ß-thal carriers with and without HFE mutations. These results suggest that in the Balearic population the ß-thal trait does not tend to be aggravated by the co-inheritance of HFE mutations.

Apoptosis of Jurkat cells induced by serum of patients with acute severe brain injury.

OBJECTIVE: To investigate the capacity of serum samples draining from the neuronal lesions to induce apoptosis of the lymphoid Jurkat cells in vitro and to analyze whether this effect is related to patient outcome. DESIGN AND SETTING: Prospective clinical investigation in a 21-bed intensive care unit (ICU) in a university hospital. PATIENTS: Forty-two patients who had suffered from acute brain injury (traumatic brain injury or spontaneous intracranial hemorrhage) requiring intensive care. INTERVENTIONS: Blood samples were obtained simultaneously from jugular bulb vein (regional) and from central venous catheter (systemic) on admission to the ICU and after 24, 48, and 72 h. Jurkat cells were incubated in the presence of 10% of heat-inactivated patients sera. The percentages of apoptotic cultured cells was measured by staining with annexin V and propidium iodide. MEASUREMENTS AND RESULTS: Regional serum draining from the lesions induced higher percentages of early and late apoptotic cells than systemic serum. The apoptotic effect was clearer with the sera from the patients who developed brain death. The apoptotic effect maintained a relationship with the mortality and the functional outcome at 6 months after the injury. CONCLUSIONS: Despite being performed on lymphoid cells because of the easier technical handling, our data help to elucidate the role of apoptosis for brain damage in acute brain injury. This and other undergoing studies on neuronal cells will enhance the understanding and management of apoptotic cell death in patients with acute brain injury admitted to the ICU.

Telomere shortening in sleep apnea syndrome.

BACKGROUND: Telomere length (TL) in circulating leukocytes relates to the chronological age of the individual but it is believed to reflect also the cumulative burden of oxidative stress and inflammation over the life-time. Shortening of TL has been reported in several chronic conditions characterized by oxidative stress and inflammation, such as diabetes and atherosclerosis. Because these conditions also occur in patients with Obstructive Sleep Apnea Syndrome (OSAS), we hypothesized that TL would be reduced in patients with OSAS. METHODS: We compared TL in 256 patients with OSAS and 148 controls without OSAS. We also investigated if TL was related to the severity of OSAS, the presence of metabolic disorders and/or cardiovascular risk factors in these patients. RESULTS: TL was significantly shorter in patients with OSAS than in controls (p<0.001). This difference persisted after adjustment for age, body mass index, cholesterol, triglycerides, glucose, and uric acid levels, smoking status and the presence of arterial hypertension (p=0.018). TL was not related to the severity of OSAS as assessed by the apnea-hypopnea index, nocturnal oxygen saturation and daytime sleepiness. CONCLUSIONS: TL in circulating leukocytes is shorter in patients with OSAS than subjects without OSAS. The mechanism of this observation is unresolved since it appears independent of chronological age, the severity of OSAS and/or the presence of cardiovascular or metabolic alterations but the potential utility of TL as a biomarker of increased cardiovascular risk in these patients justifies further studies.

Induction of cell death by sera from patients with acute brain injury as a mechanism of production of autoantibodies.

OBJECTIVE: To investigate the capacity of blood draining from the central nervous system of patients with acute brain injury to induce cell death, and to determine whether this phenomenon could be a way to induce the production of autoantibodies. METHODS: The induction of cell death of several human leukemia cell lines cultured in vitro in the presence of serum collected from the brain or the systemic circulation of patients with acute brain injury was analyzed by flow cytometry after staining with annexin V and propidium iodide. The percentages of apoptotic lymphocytes derived directly from the patients were also quantified. To investigate the mechanisms responsible for the induction of cell death, the expression of apoptosis-related molecules, as well as the effect of addition of several molecules known to interfere with apoptosis, was evaluated in the cell cultures. The presence of serum autoantibodies at the time of injury and 6 months later was studied. RESULTS: Systemic serum and, especially, serum draining from the brain lesions induced the in vitro death of the leukemia cell lines used. Moreover, there were higher percentages of ex vivo dead lymphocytes in regional blood than in systemic blood 48 hours after injury. These effects seemed to be induced by an exogenous and/or endogenous opioid, since they were blocked by the opioid antagonist, naloxone. Furthermore, such effects were mediated by an increased expression of Bax. Importantly, apoptotic Jurkat cells were bound to autoantibodies, and patients with acute brain injury produced serum autoantibodies some months after the injury. However, they did not develop a full autoimmune disease at that time. CONCLUSION: Serum factors from acute brain injuries induce cell death, both in vivo and in vitro. Apoptotic cells and, even more so, necrotic cells in acute brain injury are potential sources for autoantigen presentation that may stimulate autoimmune responses.