Tales from the Listserv
Dear Clinical Immunology-oriented colleagues,
In our opinion, by enabling us to consult and ask for previous experiences from our colleagues, the CIS PIDD-Listserv is an invaluable service to us all taking care of rare immunologic disorders.
There has been one feature missing, thus far. To solve the problems presented, there is often lively discussion on the forum during the first few days. However, we will rarely learn if any of the given suggestions in fact solved the issue. Thus, CIS is proud to present “Tales from the Listserv”, where approximately 10 times a year we will follow up discussion threads and check if the problems presented actually were solved, and whether the discussions through the forum helped to solve them. These series were originally suggested by the CIS President, Prof. John (Jack) M. Routes from Milwaukee, Wisconsin.
In our minds, we like to classify the discussions on CIS PIDD-Listserv as generally falling into three broad and partly overlapping categories:
- interesting rare cases
- interesting discussions on therapeutic approaches
- and educational cases of common immunologic diseases with important discussions around potential immunologic therapies, patient selection, effectiveness, side effects and long-term tolerability.
Tale 2: Lymphopenic states associated with chylothorax presented by children after thoracic duct ligation for complex congenital cardiac defects
The second question we have chosen for the CIS Tales from the Listserve was posted several times during recent years in the CIS-PIDD list serve.
It is about the lymphopenic states associated with chylothorax presented by children after thoracic duct ligation for complex congenital cardiac defects. A very interesting discussion on this theme is presented by Richard Wasserman, from Dallas TX in June 13, 2013. The full discussion can be found here:
Congenital heart defects are the most common birth defects, occurring in approximately 1 in 100 babies. Congenital heart problems range from simple to complex. Many heart defects don’t need treatment or can be fixed easily. But some can cause serious health problems or death requiring surgery, sometimes as soon as in the first few hours after birth.
Among the most severe congenital heart defects, such as transposition of the great arteries or Fallot’s tetralogy, children are hypoxemic. One common complication among these patients with right-sided cardiac failure or lymphangiectasia is chylothorax, which can occur after corrective cardiac surgery as well.
About 30 percent of babies present heart defects because of changes in their chromosomes or genes. Two of these conditions are rather frequent and are associated to changes in genes associated to immunity, namely Down’s syndrome (due to trisomy of chromosome 21) and velocardiofacial syndrome, frequently associated to thymic hypoplasia and also known as Di George syndrome (due to a deletion at 22q11).
Due to this common association of congenital cardiopathies and primary immunodeficiencies, a common problem among children with cardiopathy and immunodeficiency is about the origin of the disorder of immunity, if primary (congenital) or secondary to leakage of lymph through thoracic duct.
The discussion began questioning about the size of the thymus by Mel Berger from Ohio; Robert Sokolic from the NIH asked about persistent monocytosis as a clue.
Joseph Church from Los Angeles stated that after a probable thymectomy to improve the surgical field for interrupted aortic arch correction, TRECs are usually persistently low.
Luis Gonzalez from Madrid reinforces the high probability of thymectomy after open chest surgery. Our pediatric thoracic surgeons here in our University center at São Paulo also perform thymectomy after sternotomy.
Kathleen Sullivan from Philadelphia stated that the chylous draining can be associated to the clinical and laboratory features, but if the interrupted aortic arch is of type 2 (when the interruption occurs between the left carotid artery and the left subclavian artery) it is necessary to rule out a chromosome 22q11 deletion.
Soheil Chegini from Exton, PA, warned about secondary intestinal lymphangiectasia, which can lead to intestinal loss of lymphocytes, mainly CD4+ T cells, and suggests looking for fecal alpha-1 antitrypsin to ascertain for the cause of hypoproteinemia.
Moreover, Lisa Kobrynski from Atlanta, GA stated about the importance of the lymphocyte immunophenotyping to discriminate the babies that have a thymic defect – that have a preferential T cell lymphocytopenia - from those that don’t have, as they usually lose all subsets of lymphocytes simultaneously and the proportions of T, B and NK cells are relatively preserved.
James Verbsky from Milwaukee, WI affirmed that normal TRECs at day 2 of birth is of paramount importance in this question, as this finding can almost rule out primary thymus dysplasia.
We thank for all of our colleagues that participated in this fruitful discussion and we wish that it turns to be helpful for solving similar problems.