The German national registry for primary immunodeficiencies (PID).

In 2009, a federally funded clinical and research consortium (PID-NET, http://www.pid-net.org) established the first national registry for primary immunodeficiencies (PID) in Germany. The registry contains clinical and genetic information on PID patients and is set up within the framework of the existing European Database for Primary Immunodeficiencies, run by the European Society for Primary Immunodeficiencies. Following the example of other national registries, a central data entry clerk has been employed to support data entry at the participating centres. Regulations for ethics approvals have presented a major challenge for participation of individual centres and have led to a delay in data entry in some cases. Data on 630 patients, entered into the European registry between 2004 and 2009, were incorporated into the national registry. From April 2009 to March 2012, the number of contributing centres increased from seven to 21 and 738 additional patients were reported, leading to a total number of 1368 patients, of whom 1232 were alive. The age distribution of living patients differs significantly by gender, with twice as many males than females among children, but 15% more women than men in the age group 30 years and older. The diagnostic delay between onset of symptoms and diagnosis has decreased for some PID over the past 20 years, but remains particularly high at a median of 4 years in common variable immunodeficiency (CVID), the most prevalent PID.

Cerebral blood flow response to hypercapnia in immature fetal sheep.

We have reported recently that the cerebral blood flow (CBF) response to isocapnic hypoxic hypoxia is blunted in fetal sheep in utero at 93 days of gestation (term = 145-150 days), a time of rapid brain differentiation in this species. Cerebral O2 transport fell rather than being maintained, as it is in more mature fetuses. The reason for the blunted response was not clear. We hypothesized that the CBF response to hypercapnia also might be blunted. We studied 10 immature fetal sheep in utero at a mean gestational age of 92 days 24 h after catheters were placed into the superior sagittal sinus, axillary artery, and inferior vena cava. We raised the fetal arterial carbon dioxide tension (PaCO2) by changing the mother's inspired PCO2. CBF was measured before and during hypercapnia by the microsphere method. The overall increase in CBF in response to hypercapnia in immature fetuses was lower than in near-term fetuses. However, the difference was eliminated after correcting for differences in cerebral O2 consumption. This study failed to show any defect in the ability of cerebral vessels in immature fetal sheep to respond to carbon dioxide.