ALBERT

Description: WHIM syndrome is a rare congenital immunodeficiency disorder characterized by warts, hypogammaglobulinemia, infections, and myelokathexis (neutropenia because of impaired egress from the BM); most patients also have severe panleukopenia. Because WHIM syndrome is caused by mutations in the chemokine receptor CXCR4 that result in increased agonist-dependent signaling, we hypothesized that the CXCR4 antagonist plerixafor (Mozobil [Genyzme Corporation], AMD3100), might be an effective treatment. To test this, we enrolled 3 unrelated adult patients with the most common WHIM mutation, CXCR4R334X, in a phase 1 dose-escalation study. Plerixafor increased absolute lymphocyte, monocyte, and neutrophil counts in blood to normal without significant side effects in all 3 patients. Peak responses occurred at 3-12 hours after injection and waned by 24 hours after injection which tracked the drug's pharmacokinetics. All 3 cell types increased in a dose-dependent manner with the rank order of responsiveness absolute lymphocyte 〉 monocyte 〉 neutrophil. These data provide the first pharmacologic evidence that panleukopenia in WHIM syndrome is caused by CXCL12-CXCR4 signaling-dependent leukocyte sequestration, and support continued study of plerixafor as mechanism-based therapy in this disease. This study is registered at http://www.clinicaltrials.gov as NCT00967785.

Description: Chronic Granulomatous Disease (CGD) results from a mutation in the NADPH oxidase complex. As a result, patients are prone to recurrent infections and an increased risk of autoimmune disorders such as colitis. Currently, the only available cure is hematopoietic stem cell transplantation using a related or unrelated donor. In 2002, the NIH published their results using a nonmyeloablative regimen and sibling matched donors. Although the results were overall promising, there was still significant GvHD in older patients and a number of graft rejections in the younger patients. Further accrual was limited due to donor unavailability. In 2007, after establishing an agreement with the National Marrow Donor Program, we were able to initiate a protocol for patients with primary immunodeficiencies using an HLA matched unrelated donor. The goal of this protocol was to achieve engraftment in patients with CGD, including high risk patients due to the presence of an ongoing infection or inflammation, without increasing the rate of graft versus host disease. We therefore devised a novel conditioning regimen of Busulfan, Campath, and TBI along with sirolimus as the sole GVHD prophylaxis. To date we have transplanted 21 evaluable patients. Results are summarized below:AgeInfectionInflammationaGvHDcGvHDadditional cells?A&Wcause of death32XX1Nrefused dialysis25XGrade 1Y21XXGrade 1Y19X (colostomy)Grade 4XNinfection, GvHD of skin17XX2NEvan's/TRALI/GvHD17XNpulmonary hemorrhage17XGrade 2Y12XlimitedXY7XY8XY8X (colostomy)Grade 1Y8XXY6XX3NGvHD after 3rd transplant5XY4XY4XXGrade 2Y17Y11Grade 1Y10Y10Y8Y 1. Received peripheral blood stem cells from same donor after receiving bone marrow 2. Received cells after additional conditioning in the setting of Evan’s syndrome 3. Received additional cells with initial graft failure. Went on to a second then third transplant with a different conditioning regimen and different donor. Overall survival was 76%; however all deaths occurred in high risk patients and 2 of the 5 were unrelated to the initial transplant. Further, all surviving patients transplanted with high risk disease (11 of the 16) continue to have stable engraftment and had complete resolution of their inflammation and/or infection. This includes a patient with P40phox deficiency whose primary manifestation of CGD was colitis as well as a patient with an invasive fungal infection requiring emergency laminectomy 3 weeks prior to transplant. We have had limited GvHD to date and this occurred primarily in the high risk patients (6 of the 7). The most severe GvHD occurred in a patient given additional cells due possible poor engraftment and persistent thrombocytopenia. In retrospect, this may have been a sign of GvHD and not graft failure; however the result was severe GvHD of the skin and ultimately death from sepsis. Further, the only chronic GvHD (transient, now resolved) was also in a patient given additional cells for concerns of possible graft failure. Subsequently, the protocol was modified to no longer give additional unmanipulated cells and no graft failures or any severe GvHD has occurred in any of the subsequent patients. In general, patients tolerated the transplant well, although we did see a higher than expected rate of engraftment syndrome, again in the high risk patients only (5 of 21). Many patients needed only 1 or 2 transfusions of either platelets or red blood cells and 3 did not require any transfusions at all. We also transplanted two patients with CGD/McLeod’s, banking autologous blood prior to the transplant, and only one patient required any blood (1 autologous unit). Three patients did require multiple infusions due to prolonged time to engraftment or slow platelet recovery including the one patient to receive bone marrow as their initial donor product. For the one patient with late graft failure, there was autologous recovery. Thus in this single centre study we have transplanted 21 patients to date including 16 of those considered high risk using a novel non-myeloablative transplant regimen and an unrelated donor. We have had significantly lower rates of GvHD (33%) of which

Description: Chronic Granulomatous Disease is an inherited immunodeficiency resulting from a defect in one of 5 proteins necessary for the production of NADPH oxidase, an important component in managing infections by neutrophils. The most common form of the disease is X-linked due to mutations in the GP91 protein. Patients with CGD are thus prone to various infections from specific bacteria and/or fungi, but generally have normal viral responses. They are also prone to inflammatory diseases, including sarcoid, lupus, and colitis. Allogeneic hematopoieitic transplantation has been shown to be curative and will arrest or even reverse some of the inflammatory problems and is now more commonly used in patients with a history of inflammation or recurrent infections. In 2009, a new form of CGD was described resulting from a mutation in the P40 protein and to date only 2 patients have been described with this form of CGD. Unlike the other subtypes, these patients did not present with infection but in fact with severe colitis, making their diagnosis much more difficult. The role of P40 versus the other components of the NADPH oxidase does not necessarily explain this particular presentation as opposed to infection susceptibility; however assays such as DHR to test oxidase production can be misleading (both patients demonstrated only a partial reduction of oxidase production by DHR assay with normal sequencing for standard CGD subtypes) and may need to be performed specifically for a P40 dysfunction. We now report on the results of allogeneic transplant for two patients with P40 CGD. The first patient was referred to the National Institutes of Health (NIH) at the age of 9. His initial presentation was at an early age with diarrhea and perirectal abscesses. Notably, on his first EGD and colonoscopy he had evidence of granulomatous disease. He was eventually referred to a second institution for further testing and determined to have compound heterozygous mutations in the NCF4 genes with a frameshift mutation resulting in a premature stop codon in one allele and a missense mutation in the other. (Blood 114: 3309-3315, 2009) He had had a diverting ileostomy done at his referring institution as a result of his refractory colitis and was still requiring immunosuppression for his disease at the time of referral for transplant. He had no matched sibling donors and therefore underwent transplant using a 9 out of 10 matched unrelated donor. The second patient was a 17 year old male diagnosed at the age of 15, again with colitis and significant perirectal disease, with treatment including Interferon gamma, high dose corticosteroids, topical anti-inflammatories, azathioprine, and long-term antibiotics. His diagnosis of P40 CGD was made at the NIH where sequencing confirmed a compound heterozygous mutation of NCF4 with frameshift mutations in Exon 3 and Exon 9. His unaffected sister was a full match and was his donor. Both patients received busulfan (5mg/kg and 10mg/kg respectively) and Campath as part of their conditioning regimen with 300cGY of TBI also given for the MUD transplant. Sirolimus was used as the sole GvHD prophylaxis. The products were unmanipulated peripheral blood stem cell grafts (doses 8x10e6 and 10.4 x 10e6 CD34/kg respectively) and both patients had full myeloid engraftment by Day 30. The first patient had some grade 1 GvHD of the skin and GI tract initially, but is now more than 3 years post transplant and is considering revision to reconnect his ostomy with no evidence of GvHD, chronic or otherwise. The second patient is also doing well more than 1 year out, with no evidence of GvHD and has had complete resolution of his colitis off of his immunosuppression. Thus, allogeneic transplant with either a matched related or unrelated donor appears to be curative in patients with this rare form of CGD, leading to complete resolution of their inflammatory complications. Disclosures No relevant conflicts of interest to declare.

Description: WHIM syndrome is a rare, autosomal dominant, immunodeficiency disorder so-named because it is characterized by warts, hypogammaglobulinemia, infections, and myelokathexis (defective neutrophil egress from the BM). Gain-of-function mutations that truncate the C-terminus of the chemokine receptor CXCR4 by 10-19 amino acids cause WHIM syndrome. We have identified a family with autosomal dominant inheritance of WHIM syndrome that is caused by a missense mutation in CXCR4, E343K (1027G → A). This mutation is also located in the C-terminal domain, a region responsible for negative regulation of the receptor. Accordingly, like CXCR4R334X, the most common truncation mutation in WHIM syndrome, CXCR4E343K mediated approximately 2-fold increased signaling in calcium flux and chemotaxis assays relative to wild-type CXCR4; however, CXCR4E343K had a reduced effect on blocking normal receptor down-regulation from the cell surface. Therefore, in addition to truncating mutations in the C-terminal domain of CXCR4, WHIM syndrome may be caused by a single charge-changing amino acid substitution in this domain, E343K, that results in increased receptor signaling.