Outcomes of Related and Unrelated Donor Searches Among Patients with Primary Immunodeficiency Diseases Referred for Allogeneic Hematopoietic Cell Transplantation

Patients with primary immunodeficiencies (PIDs) are potentially cured by allogeneic hematopoietic cell transplantation (HCT). The spectrum of PIDs has expanded greatly beyond those that present in infancy or are diagnosed on newborn screening and require urgent, preemptive HCT. Many PID diagnoses are now made later in life, and the role of HCT is only considered for severe disease manifestations; in these cases, the kinetics and goals of a donor search may be different than for severe combined immunodeficiency. Across all PIDs, related donor searches have the additional selection factor of the inherited disease, and such searches may yield more limited options than searches for patients with hematologic malignancies; thus, unrelated donor options often become more critical in these patients. We retrospectively evaluated the outcomes of donor searches among patents with PIDs referred for HCT at the National Institutes of Health, where the minimum patient age for evaluation is 3 years and where donor options include matched sibling donors or matched related donors, HLA-haploidentical (haplo), or 7-8/8 HLA matched unrelated donors (mMUDs/MUDs). Patient (n = 161) and donor demographics, MUD search results, HLA typing, pedigrees, mutation testing, and donor selection data were collected. The National Marrow Donor Program HapLogic 8/8 HLA match algorithm was used to predict the likelihood of a successful MUD search and categorized as very good, good, fair, poor, very poor, or futile per the Memorial Sloan Kettering Cancer Center (MSKCC) Search Prognosis method. There were significant differences by PID mode of inheritance in patient age, disposition (receipt of HCT or not), donor source, and donor relatedness. A related or unrelated donor option could be identified for 94% of patients. Of living first-degree relatives (median, 3; range, 0 to 12 per patient), a median of 1 donor remained for autosomal dominant and X-linked (XL) diseases after HLA typing, mutation testing, and other exclusions, and a median of 2 donors remained for autosomal recessive (AR) diseases. Among patients with a PID of known mode of inheritance (n = 142), the best related donor was haplo for 99 (70%) patients, with 56 (39%) haplos age 40 years or older and 5 (4%) second-degree haplos; 13 (9%) had no family donor options. The best related donor was a heterozygote/asymptomatic carrier of the PID mutation in 36 (49%) patients with AR or XL disease (n = 73). Among patients with MUD search performed (n = 139), 53 (38%) had very poor/futile 8/8 MUD searches, including 6 (32%) of those with unknown PID mutation and therefore no family donor options. The MSKCC Search Prognosis was less favorable for those of non-European ancestry compared with European ancestry (P = .002). Most patients of Hispanic or African ancestry had very poor/futile MUD searches, 71% and 63%, respectively. No HCT recipients with very poor/futile MUD searches (n = 38) received 8/8 MUD grafts. Alternative donor options, including haplo and unrelated donors, are critical to enable HCT for patients with PIDs. MUD search success remains low for those of non-European ancestry, and this is of particular concern for patients with PIDs caused by an unknown genetic defect. Among patients with PIDs, related donor options are reduced and haplos age 40 years and older and/or mutation carriers are often the best family option.

Lentiviral hematopoietic stem cell gene therapy for X-linked severe combined immunodeficiency

X-linked severe combined immunodeficiency (SCID-X1) is a profound deficiency of T, B, and natural killer (NK) cell immunity caused by mutations inIL2RGencoding the common chain (γc) of several interleukin receptors. Gamma-retroviral (γRV) gene therapy of SCID-X1 infants without conditioning restores T cell immunity without B or NK cell correction, but similar treatment fails in older SCID-X1 children. We used a lentiviral gene therapy approach to treat five SCID-X1 patients with persistent immune dysfunction despite haploidentical hematopoietic stem cell (HSC) transplant in infancy. Follow-up data from two older patients demonstrate that lentiviral vector γc transduced autologous HSC gene therapy after nonmyeloablative busulfan conditioning achieves selective expansion of gene-marked T, NK, and B cells, which is associated with sustained restoration of humoral responses to immunization and clinical improvement at 2 to 3 years after treatment. Similar gene marking levels have been achieved in three younger patients, albeit with only 6 to 9 months of follow-up. Lentiviral gene therapy with reduced-intensity conditioning appears safe and can restore humoral immune function to posthaploidentical transplant older patients with SCID-X1.

Haploidentical Hematopoietic Cell Transplantation with Post-Transplant Cyclophosphamide in a Patient with Chronic Granulomatous Disease and Active Infection: A First Report

PURPOSE

We describe haploidentical hematopoietic cell transplantation (HCT) with high-dose post-transplant cyclophosphamide (PTCy) in a boy with x-linked chronic granulomatous disease (CGD).

METHODS

A persistent and life-threatening fungal infection was the indication for HSCT. Non-myeloablative conditioning with PTCy (50 mg/kg days 3 and 4) was used in the absence of fully matched donors.

RESULTS

Engraftment occurred on day 24. The patient experienced Grade 2 graft-versus-host disease of the skin and gastrointestinal tract and CMV infection, both of which were controlled. Chimerism was 100 % at days 30 and 6 months. Cessation of antifungal therapy was consistent with cure of the infection.

CONCLUSIONS

Haploidentical HCT with high-dose PTCy for CGD is feasible and succeeded even in the context of active infection.

AMD3100 is a potent antagonist at CXCR4(R334X) , a hyperfunctional mutant chemokine receptor and cause of WHIM syndrome

WHIM is an acronym for a rare immunodeficiency syndrome (OMIM #193670) caused by autosomal dominant mutations truncating the C-terminus of the chemokine receptor CXC chemokine receptor 4 (CXCR4). WHIM mutations may potentiate CXCR4 signalling, suggesting that the United States Food and Drug Administration (FDA)-approved CXCR4 antagonist AnorMED3100 (AMD3100) (also known as Plerixafor) may be beneficial in WHIM syndrome. We have tested this at the preclinical level by comparing Chinese hamster ovary (CHO) and K562 cell lines matched for expression of recombinant wild-type CXCR4 (CXCR4^WT) and the most common WHIM variant of CXCR4 (CXCR4^R334X), as well as leucocytes from a WHIM patient with the CXCR4^R334X mutation versus healthy controls. We found that CXCR4^R334X mediated modestly increased signalling (∼2-fold) in all functional assays tested, but strongly resisted ligand-dependent down-regulation. AMD3100 was equipotent and equieffective as an antagonist at CXCR4^R334X and CXCR4^WT. Together, our data provide further evidence that CXCR4^R334X is a gain-of-function mutation, and support clinical evaluation of AMD3100 as mechanism-based treatment in patients with WHIM syndrome.

Geosmithia argillacea: an emerging cause of invasive mycosis in human chronic granulomatous disease

BACKGROUND

Chronic granulomatous disease (CGD) is an inherited disorder of the nicotinamide adenine dinucleotide phosphate oxidase that leads to defective production of microbicidal superoxide and other oxidative radicals, resulting in increased susceptibility to invasive infections, especially those due to fungi.

METHODS

Geosmithia argillacea was identified from cultured isolates by genomic sequencing of the internal transcribed spacer region. Isolates previously identified as Paecilomyces variotii, a filamentous fungus closely resembling G. argillacea, were also examined.

RESULTS

We identified G. argillacea as the cause of invasive mycosis in 7 CGD patients. In 5 cases, the fungus had been previously identified morphologically as P. variotii. All patients had pulmonary lesions; 1 had disseminated lesions following inhalational pneumonia. Infections involved the chest wall and contiguous ribs in 2 patients and disseminated to the brain in 1 patient. Four patients with pneumonia underwent surgical intervention. All patients responded poorly to medical treatment, and 3 died.

CONCLUSIONS

We report the first cases of invasive mycosis caused by G. argillacea in CGD patients. G. argillacea infections in CGD are often refractory and severe with a high fatality rate. Surgical intervention has been effective in some cases. G. argillacea is a previously underappreciated and frequently misidentified pathogen in CGD that should be excluded when P. variotii is identified morphologically.

Chronic granulomatous disease as a risk factor for autoimmune disease

Chronic granulomatous disease (CGD) is characterized by recurrent infections and granuloma formation. In addition, we have observed a number of diverse autoimmune conditions in our CGD population, suggesting that patients with CGD are at an elevated risk for development of autoimmune disorders. In this report, we describe antiphospholipid syndrome, recurrent pericardial effusion, juvenile idiopathic arthritis, IgA nephropathy, cutaneous lupus erythematosus, and autoimmune pulmonary disease in the setting of CGD. The presence and type of autoimmune disease have important treatment implications for patients with CGD.

Hepatic involvement and portal hypertension predict mortality in chronic granulomatous disease

BACKGROUND & AIMS

Chronic granulomatous disease (CGD) is a rare genetic disorder, predisposing affected individuals to recurrent infectious complications and shortened survival. Liver involvement in CGD includes vascular abnormalities, which may lead to noncirrhotic portal hypertension.

METHODS

To evaluate the impact of noncirrhotic portal hypertension on survival in CGD, all records from 194 patients followed up at the National Institutes of Health with CGD were reviewed. Cox proportional hazards regression was used to determine factors associated with mortality.

RESULTS

Twenty-four patients died, all from infectious complications. By Cox regression, factors associated with mortality were as follows: (1) decreases in platelet count (>9000/microL/y; hazard ratio, 4.7; P = .007), (2) alkaline phosphatase level increases (>0.25/y; hazard ratio, 4.5; P = .01) and (3) history of liver abscess (hazard ratio, 3.1; P = .03). By regression analysis, decreasing platelet count was associated with increasing portal vein diameter, splenomegaly, increased serum immunoglobulin G level, and increasing number of alanine aminotransferase increases; greater number of alkaline phosphatase level increases and abscess were both associated with increasing age and number of infections. Prospective evaluation revealed increased hepatic-venous pressure gradients in 2 patients with progressive thrombocytopenia, suggestive of portal hypertension.

CONCLUSIONS

These data suggest mortality in patients with CGD is associated with the development of noncirrhotic portal hypertension, likely owing to injury to the microvasculature of the liver from repeated systemic and hepatic infections. The slope of decline in platelet count may be a useful measure of progression of portal hypertension over time. Furthermore, the data illustrate the potential independent effect of portal hypertension on clinical outcome outside the setting of cirrhosis.

Hepatic abnormalities in patients with chronic granulomatous disease

Chronic granulomatous disease (CGD) is a rare congenital disorder characterized by repeated bacterial and fungal infections. Aside from a high incidence of liver abscess, little is known about hepatic involvement in CGD. The aim of this study was to describe the spectrum of liver abnormalities seen in CGD. The charts of 194 patients with CGD followed at the NIH were reviewed, with a focus on liver abnormalities. Liver enzyme elevations occurred on at least one occasion in 73% of patients during a mean of 8.9 years of follow-up. ALT elevations were generally transient. Although transient alkaline phosphatase (ALP) elevations were also common, persistent ALP elevations lasting up to 17.6 years were seen in 25% of patients. Liver abscess occurred in 35% of patients. Drug-induced hepatotoxicity was documented in 15% of patients but likely occurred more frequently. Hepatomegaly was found in 34% and splenomegaly in 56% of patients. Liver histology showed granulomata in 75% and lobular hepatitis in 90% of specimens. Venopathy of the portal vein was common (80%) and associated with splenomegaly. Venopathy of the central vein was also common (63%) and was associated with the number of abscess episodes. Nodular regenerative hyperplasia (NRH) was seen in 9 patients, including 6 of 12 autopsy specimens.

CONCLUSION

Liver enzyme abnormalities occur frequently in patients with CGD. In addition to liver abscesses and granulomata, drug hepatotoxicity is likely underappreciated. Vascular lesions such as venopathy and--to a lesser extent--NRH are common. The cause and clinical consequences of venopathy await prospective evaluation.