Update 1/7/2015

We are still very interested in identifying any dog with chronic granulomatous disease. This is a rare immune deficiency affecting about 50,000 people world wide. There is a very simple flow cytometry assay that can be performed on a shipped blood sample to identify CGD. We have modified this so that we can test dog blood cells and are interested in receiving blood from dogs who have the clinical constellation that indicates they could have this disorder. In humans and mice it is an X-linked disorder (and the gene is definitely also on the dog X-chromosome) so it is easy to identify the disorder in maternal carriers since they are mosaics for the failure to produce hydrogen peroxide in their neutrophils. So we are particularly interested in receiving blood from female dogs who have lost male pups to infection, particularly those types of bacterial or fungal infections noted in our listing. Sebastian Brenner has now left my lab so you might list my technician Narda Theobald to replace Sebastian. Narda's email is ntheobald@niaid.nih.gov and her telephone is 301-496-6393. We try to be very responsive to inquiries and we have screened a few dog blood samples in the past few months, but would like more. Thank you very much. Harry L. Malech, MD

Introduction:

Following is a request for samples from Dr. Harry Malech. Dr. Malech is most interested in exploring a potential dog model for an inherited human defect in phagocyte function known as chronic granulomatous disease (CGD). Examples of canine patients that may be of value to them are young Weimaraners with recurrent infection secondary to suspected neutrophil dysfunction, or young dogs from other breeds with a history of chronic recurring infections, particularly with organisms such as Aspergillus, Staphylococcus, Serratia or Burkholderia cepacia. The research of Dr. Malech as well as being, hopefully, of long term benefit to human patients, will also be of immediate diagnostic benefit to those of our canine patients in which we suspect an underlying genetic predisposition to recurrent infection.

Search For A Dog With X-Linked Chronic Granulomatous Disease:

We work on therapy for human patients with chronic granulomatous disease (CGD). CGD is a rare inherited immunodeficiency syndrome, caused by a defect in the oxygen metabolic burst (respiratory burst) in all phagocytic cells. Affected cells cannot produce superoxide, and hence are unable to kill certain bacteria and fungi. The isolated pathogens are mainly catalase positive and in humans predominantly are Staphylococcus aureus, certain enteric gram negative bacteria (Serratia marcescence, Salmonella), Burkholderia species such as cepacia and many kinds of fungi particularly Aspergillus species. Two-third of all cases are X-linked. Patients usually present early in life with severe infections such as pneumonia, abscesses, osteomyeltitis and septicemia. The leading pathological findings are granulomas. Occasionally CGD patients present with inflammatory bowel disease that can resemble Crohn's disease. Therapy for CGD patients mainly consists of symptomatic treatment with moderate to poor prognosis. Despite recent promising results with bone marrow transplantation for patients with a HLA-identical family member, most patients could only be cured by gene therapy.

To improve treatment for CGD patients and gain further knowledge about transplantation, hematopoietic stem cell engraftment and gene therapy we are looking for animal models of CGD such as a dog model. To test for CGD, we perform on a small amount of whole blood a flow cytometric assay of oxidant production called a dihydrorhodamine assay (DHR), which provides a quick and reliable diagnosis. Importantly, the DHR assay can also identify female carriers of the X-linked form of CGD because of mosaicism for the defect seen in the circulating blood leukocytes of such females.

We would like to ask for your help in a search for dogs that might have CGD. Such dogs would have recurrent infections and granulomas. Any infection with Aspergillus (fungus), Serratia (bacteria) or Burkholderia cepacia are very highly suggestive of CGD. If you have any male dogs suggestive for X-CGD or females that lose their male puppies to such infections, we would be interested in screening blood from the affected males or the mother of such animals.

All we need is:

• 3ml of blood of dogs with CGD-like recurrent infections (or potential female carriers), plus
• 3ml blood from a normal control dog.

Blood has to be collected in sodium heparin and must be shipped at room temperature. Analysis is free of charge and has to be performed within 2-3 days. Payment of shipping costs will also be covered.

We would very much appreciate your help and look forward to hearing from you.

Reviewed 01/07/2015