Hematopoietic stem cell transplantation from matched unrelated donors in chronic granulomatous disease

Functional neutrophil disorders: Chronic granulomatous disease and beyond

Since their description by Metchnikoff in 1905, phagocytes have been increasingly recognized to be the entities that traffic to sites of infection and inflammation, engulf and kill infecting organisms, and clear out apoptotic debris all the while making antigens available and accessible to the lymphoid organs for future use. Therefore, phagocytes provide the gateway and the first check in host protection and immune response. Disorders in killing and chemotaxis lead not only to infection susceptibility, but also to autoimmunity. We aim to describe chronic granulomatous disease and the leukocyte adhesion deficiencies as well as myeloperoxidase deficiency and G6PD deficiency as paradigms of critical pathways.

Geographic Variability and Pathogen-Specific Considerations in the Diagnosis and Management of Chronic Granulomatous Disease

Chronic granulomatous disease (CGD) is a rare but serious primary immunodeficiency with varying prevalence and rates of X-linked and autosomal recessive disease worldwide. Functional defects in the phagocyte nicotinamide adenine dinucleotide phosphate oxidase complex predispose patients to a relatively narrow spectrum of bacterial and fungal infections that are sometimes fastidious and often difficult to identify. When evaluating and treating patients with CGD, it is important to consider their native country of birth, climate, and living situation, which may predispose them to types of infections that are atypical to your routine practice. In addition to recurrent and often severe infections, patients with CGD and X-linked female carriers are also susceptible to developing many non-infectious complications including tissue granuloma formation and autoimmunity. The DHR-123 oxidation assay is the gold standard for making the diagnosis and it along with genetic testing can help predict the severity and prognosis in patients with CGD. Disease management focuses on prophylaxis with antibacterial, antifungal, and immunomodulatory medications, prompt identification and treatment of acute infections, and prevention of secondary granulomatous complications. While hematopoietic stem-cell transplantation is the only widely available curative treatment for patients with CGD, recent advances in gene therapy may provide a safer, more direct alternative.

Cellular Therapies in Chronic Granulomatous Disease

Allogeneic hematopoietic stem cell transplantation (HSCT) has become the main curative treatment in patients with chronic granulomatous disease (CGD). CGD is caused by inherited defects of the phagolysomal NADPH-oxidase, leading to a lifelong propensity for invasive infections and granulomatous inflammation. After successful allogeneic HSCT, chronic infections and inflammation resolve and quality-of-life improves. Favorable long-term outcome after HSCT is dependent on the prevention of primary and secondary graft failure (GF), including falling myeloid donor chimerism (DC) below 10 %, and chronic graft-vs.-host-disease (cGVHD). The risk of GF and GvHD increases with the use of HLA-incompatible donors and this may outweigh the benefits of HSCT, mainly in patients with severe co-morbidities and in asymptomatic patients with residual NADPH-oxidase function. Seventeen scientific papers have reported on a total of 386 CGD-patients treated by HSCT with HLA-matched family/sibling (MFD/MSD), 9/10-/10/10-matched-unrelated volunteer (MUD) and cord blood donors. The median OS/EFS-rate of these 17 studies was 91 and 82%, respectively. The median rates of GF, cGVHD and de-novo autoimmune diseases were 14, 10, and 12%, respectively. Results after MFD/MSD and 10/10-MUD-transplants were rather similar, but outcome in adults with significant co-morbidities and after transplants with 9/10 HLA-MUD were less successful, mainly due to increased GF and chronic GVHD. Transplantation protocols using T-cell depleted haploidentical donors with post-transplant cyclophosphamide or TCR-alpha/beta depletion have recently reported promising results. Autologous gene-therapy after lentiviral transduction of HSC achieved OS/EFS-rates of 78/67%, respectively. Careful retrospective and prospective studies are mandatory to ascertain the most effective cellular therapies in patients with CGD.

Reduced-intensity conditioning for hematopoietic cell transplant for HLH and primary immune deficiencies

Allogeneic hematopoietic cell transplantation (HCT) with myeloablative conditioning for disorders associated with excessive inflammation such as hemophagocytic lymphohistiocytosis (HLH) is associated with early mortality. A multicenter prospective phase 2 trial of reduced-intensity conditioning with melphalan, fludarabine, and intermediate-timing alemtuzumab was conducted for HLA matched or single HLA locus mismatched related or unrelated donor HCT in a largely pediatric cohort. Graft-versus-host disease (GVHD) prophylaxis was cyclosporine with methylprednisolone. The primary end point was 1-year overall survival (OS). Thirty-four patients with HLH and 12 with other primary immune deficiencies were transplanted. With a median follow-up of 20 months, the 1-year OS for transplanted patients was 80.4% (90% confidence interval [CI], 68.6%-88.2%). Five additional deaths by 16 months yielded an 18-month OS probability of 66.7% (90% CI, 52.9%-77.3%). Two patients experienced primary graft failure, and 18 patients either experienced a secondary graft failure or required a second intervention (mostly donor lymphocyte infusion [DLI]). At 1 year, the proportion of patients alive with sustained engraftment without DLI or second HCT was 39.1% (95% CI, 25.2%-54.6%), and that of being alive and engrafted (with or without DLI) was 60.9% (95% CI, 45.4 %-74.9%). The day 100 incidence of grade II to IV acute GVHD was 17.4% (95% CI, 8.1%-29.7%), and 1-year incidence of chronic GVHD was 26.7% (95% CI, 14.6%-40.4%). Although the trial demonstrated low early mortality, the majority of surviving patients required DLI or second HCT. These results demonstrate a need for future approaches that maintain low early mortality with improved sustained engraftment. The trial was registered at Clinical Trials.gov (NCT 01998633).

Allogeneic Hematopoietic Cell Transplantation for Chronic Granulomatous Disease: Controversies and State of the Art

Chronic granulomatous disease (CGD) is a congenital disorder characterized by recurrent life-threatening bacterial and fungal infections and development of severe inflammation secondary to a congenital defect in 1 of the 5 phagocyte oxidase (phox) subunits of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase complex. Hematopoietic cell transplant (HCT) is a curative treatment for patients with CGD that provides donor neutrophils with functional NADPH and superoxide anion production. Many characteristics of CGD, including preexisting infection and inflammation and the potential for cure with mixed-donor chimerism, influence the transplant approach and patient outcome. Because of the dangers of short-term death, graft-versus-host disease, and late effects from chemotherapy, HCT historically has been reserved for patients with high-risk disease and a matched donor. However, as advances in CGD and HCT treatments have evolved, recommendations on transplant eligibility also must be amended, but the development of modern guidelines has proven difficult. In this review, we provide an overview of HCT in patients with CGD, including the debate over HCT indications in them, the unique aspects of CGD that can complicate HCT, and a summary of transplant outcomes.

High Incidence of Autoimmune Disease after Hematopoietic Stem Cell Transplantation for Chronic Granulomatous Disease

There is a lack of consensus regarding the role and method of hematopoietic stem cell transplantation (HSCT) on patients with chronic granulomatous disease (CGD). Long-term follow-up after HSCT in these patient population is essential to know its potential complications and decide who will benefit the most from HSCT. We report the outcome of HSCT and long-term follow-up in 24 patients with CGD, transplanted in our center from either related (n = 6) or unrelated (n = 18) donors, over a 12-year period (2003 to 2015), using high-dose alemtuzumab in the preparative regimen. We evaluated the incidence and timing of adverse events and potential risk factors. We described in detailed the novel finding of increased autoimmunity after HSCT in patients with CGD. At a median follow-up of 1460 days, 22 patients were full donor chimeras, and 2 patients had stable mixed chimerism. All assessable patients showed normalization of their neutrophil oxidative burst test. None of the patients developed grades II to IV acute graft-versus-host disease, and no patient had chronic graft-versus-host disease. Twelve of 24 patients developed 17 autoimmune diseases (ADs). Severe ADs (cytopenia and neuropathy) occurred exclusively in the unrelated donor setting and mainly in the first year after HSCT, whereas thyroid AD occurred in the related donor setting as well and more than 3 years after HSCT. Two patients died due to infectious complications after developing autoimmune cytopenias. One additional patient suffered severe brain injury. The remaining 21 patients have long-term Lansky scores ≥ 80. The outcome of HSCT from unrelated donors is comparable with related donors but might carry an increased risk of developing severe AD. A lower dose of alemtuzumab may reduce this risk and should be tested in further studies.

A Review of Chronic Granulomatous Disease

Chronic granulomatous disease (CGD) is a primary immunodeficiency caused by defects in any of the five subunits of the NADPH oxidase complex responsible for the respiratory burst in phagocytic leukocytes. Patients with CGD are at increased risk of life-threatening infections with catalase-positive bacteria and fungi and inflammatory complications such as CGD colitis. The implementation of routine antimicrobial prophylaxis and the advent of azole antifungals has considerably improved overall survival. Nevertheless, life expectancy remains decreased compared to the general population. Inflammatory complications are a significant contributor to morbidity in CGD, and they are often refractory to standard therapies. At present, hematopoietic stem cell transplantation (HCT) is the only curative treatment, and transplantation outcomes have improved over the last few decades with overall survival rates now > 90% in children less than 14 years of age. However, there remains debate as to the optimal conditioning regimen, and there is question as to how to manage adolescent and adult patients. The current evidence suggests that myeloablative conditioning results is more durable myeloid engraftment but with increased toxicity and high rates of graft-versus-host disease. In recent years, gene therapy has been proposed as an alternative to HCT for patients without an HLA-matched donor. However, results to date have not been encouraging. with negligible long-term engraftment of gene-corrected hematopoietic stem cells and reports of myelodysplastic syndrome due to insertional mutagenesis. Multicenter trials are currently underway in the United States and Europe using a SIN-lentiviral vector under the control of a myeloid-specific promoter, and, should the trials be successful, gene therapy may be a viable option for patients with CGD in the future.

Allogeneic hematopoietic stem cell transplantation for nonmalignant hematologic disorders using chemotherapy-only cytoreductive regimens and T-cell-depleted grafts from human leukocyte antigen-matched or -mismatched donors

Nonmalignant hematologic disorders (NMHD) of childhood comprise a variety of disorders, including acquired severe aplastic anemia and inherited marrow failure syndromes. Patients with high-risk NMHD without matched related donors fare poorly with allogeneic hematopoietic alternative donor stem cell transplantation (allo-HSCT) and are at high risk for developing graft-versus-host disease following unmodified grafts. The authors retrospectively analyzed data on 18 patients affected by NMHD, lacking a human leukocyte antigen (HLA)-identical sibling donor, who underwent an alternative donor allo-HSCT at their institution between April 2005 and May 2013. Fifty percent of the patients had received prior immunosuppressive therapy, 72% had a history of infections, and 56% were transfusion dependent at the time of transplant. Cytoreduction included a combination of 3 of 5 agents: fludarabine, melphalan, thiotepa, busulfan, and cyclophosphamide. Grafts were T-cell depleted. All evaluable patients engrafted. Five died of transplant complications. The cumulative incidence of graft-versus-host disease was 6%. No patient had recurrence of disease. Five-year overall survival was 77%. Age at transplant <6 years was strongly associated with better survival. Based on these results, transplant with chemotherapy-only cytoreductive regimens and T-cell-depleted stem cell transplants could be recommended for patients with high-risk NMHD, especially at a younger age.

A Single-Center Experience Comparing Alemtuzumab, Fludarabine, and Melphalan Reduced-Intensity Conditioning with Myeloablative Busulfan, Cyclophosphamide, and Antithymocyte Globulin for Chronic Granulomatous Disease

Myeloablative conditioning (MAC) regimens are commonly used in transplantation for chronic granulomatous disease (CGD) but are associated with toxicity. Reduced-intensity conditioning (RIC) regimens have lower toxicity but may fail to achieve stable donor chimerism. We report a comparison between 4 patients who received a RIC regimen consisting of alemtuzumab (1 mg/kg), fludarabine (150 mg/m²), and melphalan (140 mg/m²) and 14 patients who received a MAC regimen consisting of busulfan (area under the curve, 1800 to 2000 µMol/min twice daily × 4 days), cyclophosphamide (50 mg/kg/day × 4), and antithymocyte globulin (15 mg/kg twice daily on days -2 and -1, then daily on days +1 and +2). Seventy-five percent (n = 3) of RIC patients developed mixed chimerism and needed either withdrawal of immune suppression (n = 1) or additional stem cell products (n = 2) to achieve stable donor chimerism. Ninety-two percent (n = 13) of patients in the MAC group maintained >95% donor chimerism. Complications included acute graft-versus-host disease (MAC 64%, RIC 0%), chronic graft-versus-host disease (MAC 28%, RIC 0%), sinusoidal obstructive syndrome (MAC 7%, RIC 0%), bacteremia (MAC 42%, RIC 0%), fungemia (MAC 14%, RIC 0%), viral disease (MAC 7%, RIC 25%), and death (MAC 21%, RIC 0%). A RIC regimen has lower toxicity but frequently requires interventions to maintain donor chimerism compared with a MAC regimen in CGD.

Chronic granulomatous disease - conventional treatment vs. hematopoietic stem cell transplantation: an update

PURPOSE OF REVIEW

We update and summarize the recent findings in conventional treatment and hematopoietic stem cell transplantation in chronic granulomatous disease (CGD). We also summarize the contemporary view on when hematopoietic stem cell transplantation should be the preferred treatment of choice in CGD.

RECENT FINDINGS

Azole antifungal treatment in CGD has improved survival. With prolonged survival, inflammatory complications are an emerging problem in CGD. Several studies now present excellent results with stem cell transplantation in severe CGD, also with reduced intensity conditioning.

SUMMARY

Several lines of evidence now suggest that stem cell transplantation should be the preferred treatment of choice in severe CGD, if there is an available donor. This should be performed as soon as possible to avoid severe sequelae from infection and inflammation.

Reduced-intensity conditioning for hematopoietic cell transplantation of chronic granulomatous disease

Hematopoietic cell transplantation (HCT) is the only available curative therapy for chronic granulomatous disease (CGD), but its use is limited by transplant-related mortality (TRM) in patients who often come to transplant with existing infections or organ dysfunction. Reduction in the intensity of the preparative regimen mitigates these risks, but increases the potential for mixed donor-recipient chimerism (MC) that may progress to graft loss. Recently a busulfan-based reduced-intensity conditioning (RIC) regimen has been described with excellent survival and little MC. We report our experience with a similar RIC regimen at our institution, demonstrating problems with donor chimerism and graft loss. Pediatr Blood Cancer 2015;62:359-361. © 2014 Wiley Periodicals, Inc.

Advances in the diagnosis and treatment of chronic granulomatous disease

PURPOSE OF REVIEW

Chronic granulomatous disease (CGD), characterized 50 years ago as a primary immunodeficiency disorder of phagocytic cells (resulting in failure to kill a defined spectrum of bacteria and fungi and in concomitant chronic granulomatous inflammation) now comprises five genetic defects impairing one of the five subunits of phagocyte NADPH oxidase (Phox). Phox normally generates reactive oxygen species (ROS) engaged in intracellular and extracellular host defence and resolving accompanying inflammatory processes. 'Fatal' granulomatous disease has now changed into a chronic inflammatory condition with a median survival of 35 years and is now of interest to both paediatricians and internists. Clinical vigilance and expert knowledge are needed for early recognition and tailored treatment of this relatively rare genetic disorder.

RECENT FINDINGS

Infections by unanticipated pathogens and noncirrhotic portal hypertension need to be recognized as new CGD manifestations. Adult-onset CGD too is increasingly observed even in the elderly. Conservative treatment of fungal infections needs close monitoring due to the spread of azole resistance following extensive use of azoles in agriculture. Curative haematopoietic stem cell transplantation (HSCT) in early childhood has expanded with impressive results following use of matched, unrelated or cord blood donors and of a reduced intensity conditioning (RIC) regimen. Gene therapy, however, still has major limitations, remaining experimental.

SUMMARY

CGD is more prevalent than initially believed with a birth prevalence of 1: 120 000. As patients are increasingly diagnosed around the world and grow older, further manifestations of CGD are expected. While fungal infections have lost some threat, therapeutic research focuses on two other important aims: pharmacologic cure of chronic inflammation and long-term cure of CGD by gene therapy.

Dramatic Improvement in the Multifocal Positron Emission Tomography Findings of a Young Adult with Chronic Granulomatous Disease Following Allogeneic Hematopoietic Stem Cell Transplantation

Chronic granulomatous disease (CGD) is a primary immunodeficiency caused by defects of nicotinamide adenine dinucleotide phosphate oxidase. Catalase-positive bacteria and fungi are phagocytosed, but persist within phagocytes, resulting in granulomatous inflammation. Although allogeneic hematopoietic stem cell transplantation (HSCT) is a curative treatment for CGD, HSCT sometimes leads to fatal outcomes related to the exacerbation of persistent infectious or post-infectious inflammatory diseases, particularly in adolescent and young adult patients with a history of recurrent infections and/or multiple granulomas in organs. Here, we present the case of a young adult with X-linked CGD in whom multiple lesions were found in lungs and lymph nodes on both computed tomography and positron emission tomography (PET) scans before allogeneic HSCT, but all the lesions disappeared only on PET scan 5 months after HSCT. Monitoring the activity of multiple pre-existing lesions with PET scan may be beneficial to adolescent and young adult CGD-patients undergoing allogeneic HSCT.

Primary Immune Deficiency Treatment Consortium (PIDTC) report

The Primary Immune Deficiency Treatment Consortium (PIDTC) is a network of 33 centers in North America that study the treatment of rare and severe primary immunodeficiency diseases. Current protocols address the natural history of patients treated for severe combined immunodeficiency (SCID), Wiskott-Aldrich syndrome, and chronic granulomatous disease through retrospective, prospective, and cross-sectional studies. The PIDTC additionally seeks to encourage training of junior investigators, establish partnerships with European and other International colleagues, work with patient advocacy groups to promote community awareness, and conduct pilot demonstration projects. Future goals include the conduct of prospective treatment studies to determine optimal therapies for primary immunodeficiency diseases. To date, the PIDTC has funded 2 pilot projects: newborn screening for SCID in Navajo Native Americans and B-cell reconstitution in patients with SCID after hematopoietic stem cell transplantation. Ten junior investigators have received grant awards. The PIDTC Annual Scientific Workshop has brought together consortium members, outside speakers, patient advocacy groups, and young investigators and trainees to report progress of the protocols and discuss common interests and goals, including new scientific developments and future directions of clinical research. Here we report the progress of the PIDTC to date, highlights of the first 2 PIDTC workshops, and consideration of future consortium objectives.

Reduced-intensity conditioning and HLA-matched haemopoietic stem-cell transplantation in patients with chronic granulomatous disease: a prospective multicentre study

BACKGROUND

In chronic granulomatous disease allogeneic haemopoietic stem-cell transplantation (HSCT) in adolescents and young adults and patients with high-risk disease is complicated by graft-failure, graft-versus-host disease (GVHD), and transplant-related mortality. We examined the effect of a reduced-intensity conditioning regimen designed to enhance myeloid engraftment and reduce organ toxicity in these patients.

METHODS

This prospective study was done at 16 centres in ten countries worldwide. Patients aged 0-40 years with chronic granulomatous disease were assessed and enrolled at the discretion of individual centres. Reduced-intensity conditioning consisted of high-dose fludarabine (30 mg/m(2) [infants <9 kg 1·2 mg/kg]; one dose per day on days -8 to -3), serotherapy (anti-thymocyte globulin [10 mg/kg, one dose per day on days -4 to -1; or thymoglobuline 2·5 mg/kg, one dose per day on days -5 to -3]; or low-dose alemtuzumab [<1 mg/kg on days -8 to -6]), and low-dose (50-72% of myeloablative dose) or targeted busulfan administration (recommended cumulative area under the curve: 45-65 mg/L × h). Busulfan was administered mainly intravenously and exceptionally orally from days -5 to -3. Intravenous busulfan was dosed according to weight-based recommendations and was administered in most centres (ten) twice daily over 4 h. Unmanipulated bone marrow or peripheral blood stem cells from HLA-matched related-donors or HLA-9/10 or HLA-10/10 matched unrelated-donors were infused. The primary endpoints were overall survival and event-free survival (EFS), probabilities of overall survival and EFS at 2 years, incidence of acute and chronic GVHD, achievement of at least 90% myeloid donor chimerism, and incidence of graft failure after at least 6 months of follow-up.

FINDINGS

56 patients (median age 12·7 years; IQR 6·8-17·3) with chronic granulomatous disease were enrolled from June 15, 2003, to Dec 15, 2012. 42 patients (75%) had high-risk features (ie, intractable infections and autoinflammation), 25 (45%) were adolescents and young adults (age 14-39 years). 21 HLA-matched related-donor and 35 HLA-matched unrelated-donor transplants were done. Median time to engraftment was 19 days (IQR 16-22) for neutrophils and 21 days (IQR 16-25) for platelets. At median follow-up of 21 months (IQR 13-35) overall survival was 93% (52 of 56) and EFS was 89% (50 of 56). The 2-year probability of overall survival was 96% (95% CI 86·46-99·09) and of EFS was 91% (79·78-96·17). Graft-failure occurred in 5% (three of 56) of patients. The cumulative incidence of acute GVHD of grade III-IV was 4% (two of 56) and of chronic graft-versus-host disease was 7% (four of 56). Stable (≥90%) myeloid donor chimerism was documented in 52 (93%) surviving patients.

INTERPRETATION

This reduced-intensity conditioning regimen is safe and efficacious in high-risk patients with chronic granulomatous disease.

FUNDING

None.

[A therapeutic approach towards chronic granulomatous disease]

Chronic granulomatous disease (CGD) is a primary immunodeficiency (PID) characterized by the inability of phagocytes to produce reactive oxygen intermediates (ROIs) due to a defect in the NADPH oxidase complex. Recent studies have revealed that ROIs are involved in inflammatory signaling in phagocytes, illuminating the underlying mechanisms of hyper-inflammation in CGD. CGD patients frequently suffer from CGD-associated bowel inflammation, granuloma, and life-threatening infections. Based on the discovery of the regulatory function of ROIs in the immune response, therapeutic methods for excessive inflammation focusing on inflammatory cytokines are being developed for CGD. Although hematopoietic stem cell (HSC) transplantation (HSCT) is a curative therapy for CGD, successful transplants greatly depend on HSC source selection and the degree of matching of potential donors. Gene therapy trials for PID have been performed on over 120 patients with no HLA identical donor for HSCT, and have demonstrated clinical benefits. Genotoxicity in HSC gene therapy trials has expanded our knowledge on the mechanisms of vector-associated clonal expansion of gene-modified cells, which will advance gene therapy development using self-inactivating retrovirus and lentivirus vectors. We will discuss the complications of HSCT for CGD. We will then outline the status of gene therapy approaches in the treatment of CGD.

Chronic granulomatous disease-haematopoietic stem cell transplantation versus conventional treatment

AIM

Chronic granulomatous disease (CGD) is a rare X-linked or autosomal recessive primary immune deficiency characterized by recurrent, life-threatening bacterial and fungal infections. Mortality rates are high with conventional treatment. However, haematopoietic stem cell transplantation (HSCT) offers cure. Here, we compare the outcome of HSCT in 14 Swedish patients with CGD to that in 27 patients with CGD who were given conventional treatment.

METHODS

Forty-one patients in Sweden were diagnosed with CGD between 1990 and 2012. From 1997 to 2012, 14 patients with CGD, aged 1-35 years, underwent HSCT and received grafts either from an HLA-matched sibling donor or a matched unrelated donor.

RESULTS

Thirteen of the 14 transplanted patients are alive and well. Mean age at transplantation was 10.4 years, and the mean survival time was 7.7 years. In contrast, seven of 13 Swedish men or boys with X-linked CGD who were treated conventionally died from complications of CGD at a mean age of 19 years, while the remaining patients suffered life-threatening infections.

CONCLUSION

The outcome of the patients who underwent HSCT supports HSCT as being the preferable treatment for severe CGD. Our results advocate early HSCT for all patients with X-linked CGD, using grafts from either a matched sibling donor or a matched unrelated donor.

Invasive fungal infection in chronic granulomatous disease: insights into pathogenesis and management

PURPOSE OF REVIEW

Invasive fungal infections (IFIs) remain a major cause of death in patients with chronic granulomatous disease (CGD). We discuss the new insights into the pathogenesis, diagnosis, prevention, and management of invasive fungal infections in patients with CGD.

RECENT FINDINGS

CGD has the highest prevalence of IFIs among the immunodeficiencies. Infections typically involve the lung, and the most commonly isolated pathogen is Aspergillus spp. However, IFIs due to rare opportunistic filamentous fungi are increasingly reported. Most IFIs are diagnosed on routine chest imaging, and serum markers such as galactomannan and 1,3-β-D-glucan are of limited value in CGD. Routine use of itraconazole for prophylaxis continues to be recommended, although posaconazole may be an alternative. Management of IFIs is typically centered on prolonged courses of antifungal therapy. Surgery may be required for complete resolution, especially in the setting of osteomyelitis or infections due to Aspergillus nidulans or other poorly responsive molds. Hematopoietic stem cell transplantation (HSCT) cures CGD and may be appropriate in select patients with refractory IFIs.

SUMMARY

Management of IFIs in CGD has significantly improved over the last decade. Earlier diagnosis of IFIs, accurate identification of pathogens, and development of reliable susceptibility testing are areas for future emphasis. HSCT is a promising therapy, even during refractory infections in CGD.

Myeloablative transplantation using either cord blood or bone marrow leads to immune recovery, high long-term donor chimerism and excellent survival in chronic granulomatous disease

The curative potential of hematopoietic stem cell transplantation in patients with chronic granulomatous disease depends on availability of a suitable donor, successful donor engraftment, and maintenance of long-term donor chimerism. Twelve consecutive children (median age, 59.5 months; range, 8-140 months) with severe chronic granulomatous disease (serious bacterial/fungal infections pretransplantation; median, 3; range, 2-9) received myeloablative hematopoietic stem cell transplantation using sibling bone marrow ([SibBM]; n = 5), unrelated cord blood (UCB; n = 6), and sibling cord blood (n = 1) at our center between 1997 and 2010. SibBM and sibling cord blood were HLA matched at 6/6, whereas UCB were 5/6 (n = 5) or 6/6 (n = 1). Recipients of SibBM were conditioned with busulfan and cyclophosphamide ± anti-thymocyte globulin (ATG), whereas 6 of 7 cord blood recipients received fludarabine/busulfan/cyclophosphamide/ATG. Seven patients received granulocyte-colony stimulating factor-mobilized granulocyte transfusions from directed donors. The first 2 UCB recipients had primary graft failure but successfully underwent retransplantation with UCB. Highest acute graft-versus-host disease was grade III (n = 1). Extensive chronic graft-vs-host disease developed in 3 patients. All patients are alive with median follow-up of 70.5 months (range, 12-167 months) with high donor chimerism (>98%, n = 10; 94%, n = 1; and 92%, n = 1). Myeloablative hematopoietic stem cell transplantation led to correction of neutrophil dysfunction, durable donor chimerism, excellent survival, good quality of life, and low incidence of graft-vs-host disease regardless of graft source.

Excellent survival after sibling or unrelated donor stem cell transplantation for chronic granulomatous disease

BACKGROUND

Matched related donor (MRD) hematopoietic stem cell transplantation (HSCT) is a successful treatment for chronic granulomatous disease (CGD), but the safety and efficacy of HSCT from unrelated donors is less certain.

OBJECTIVE

We evaluated the outcomes and overall survival in patients with CGD after HSCT.

METHODS

We report the outcomes for 11 children undergoing HSCT from an MRD (n = 4) or an HLA-matched unrelated donor (MUD) (n = 7); 9 children were boys, and the median age was 3.8 years (range, 1-13 years). We treated both X-linked (n = 9) and autosomal recessive (n = 2) disease. Nine children had serious clinical infections before transplantation. The conditioning regimens contained busulfan, cyclophosphamide, cytarabine, or fludarabine according to the donor used. All patients received alemtuzumab (anti-CD52 antibody). Additional graft-versus-host disease (GvHD) prophylaxis included cyclosporine and methotrexate for MUD recipients and cyclosporine and prednisone for MRD recipients.

RESULTS

Neutrophil recovery took a median of 16 days (range, 12-40 days) and 18 days (range, 13-24 days) for MRD and MUD recipients, respectively. Full donor neutrophil engraftment occurred in 9 patients, and 2 had stable mixed chimerism; all patients had sustained correction of neutrophil oxidative burst defect. Four patients had grade I skin acute GVHD responding to topical treatment. No patient had grade II to IV acute GvHD or chronic GvHD. All patients are alive between 1 and 8 years after HSCT.

CONCLUSION

For CGD, equivalent outcomes can be obtained with MRD or MUD stem cells, and HSCT should be considered an early treatment option.

Cutaneous manifestations of DOCK8 deficiency syndrome

BACKGROUND

Mutations in the dedicator of cytokinesis 8 gene (DOCK8) cause a combined primary immunodeficiency syndrome that is characterized by elevated serum IgE levels, depressed IgM levels, eosinophilia, sinopulmonary infections, cutaneous viral infections, and lymphopenia. Many patients with DOCK8 deficiency were previously thought to have a variant of Job's syndrome. Distinguishing between DOCK8 deficiency and Job's syndrome, also referred to as autosomal dominant hyper-IgE syndrome, on the basis of clinical findings alone is challenging. The discovery of the DOCK8 mutation has made it possible to differentiate the cutaneous manifestations of these hyper-IgE syndromes.

OBSERVATIONS

Twenty-one patients from 14 families with confirmed homozygous or compound heterozygous mutations in DOCK8 were evaluated. Clinical findings included dermatitis, asthma, food and environmental allergies, recurrent sinopulmonary infections, staphylococcal skin abscesses, and severe cutaneous viral infections. Malignant neoplasms, including aggressive cutaneous T-cell lymphoma, anal and vulvar squamous cell carcinomas, and diffuse large B-cell lymphoma, developed in 5 patients during adolescence and young adulthood.

CONCLUSIONS

DOCK8 deficiency and Job's syndrome share several clinical features, including elevated serum IgE levels, dermatitis, recurrent sinopulmonary infections, and cutaneous staphylococcal abscesses. However, the presence of recalcitrant, widespread cutaneous viral infections, asthma, and food and environmental allergies, as well as the absence of newborn rash and coarse facies, favors the clinical diagnosis of DOCK8 deficiency. Rates of malignancy and overall mortality in patients with DOCK8 deficiency were higher than in those with Job's syndrome, highlighting the value of distinguishing between these conditions and the importance of close monitoring for neoplasia.

Chronic granulomatous disease: overview and hematopoietic stem cell transplantation

Chronic granulomatous disease (CGD) still causes significant morbidity and mortality. The difficulty in considering high-risk yet curative treatments, such as allogeneic bone marrow transplantation, lies in the unpredictable courses of both CGD and bone marrow transplantation in different patients. Some patients with CGD can have frequent infections, granulomatous or autoimmune disorders necessitating immunosuppressive therapy, or both but also experience long periods of relative good health. However, the risk of death is clearly higher in patients with CGD of all types, and the complications of CGD short of death can still cause significant morbidity. Therefore, with recent developments and improvements, bone marrow transplantation, previously considered an experimental or high-risk procedure, has emerged as an important option for patients with CGD. We will discuss the complications of CGD that result in significant morbidity and mortality, particularly the most common infections and autoimmune/inflammatory complications, as well as their typical management. We will then discuss the status of bone marrow transplantation.

Gene therapy of chronic granulomatous disease: the engraftment dilemma

The potential of gene therapy as a curative treatment for monogenetic disorders has been clearly demonstrated in a series of recent Phase I/II clinical trials. Among primary immunodeficiencies, gene transfer into hematopoietic stem (HSC)/progenitor cells has resulted in the long-term correction of immune and metabolic defects in treated patients. In most cases, successes were augmented by a recognized biological selection for successfully treated cells in vivo, perhaps even to some extent at the HSC level. In contrast, similar achievements have not turned into reality for immunodeficiencies in which gene-transduced cells lack selective advantages in vivo. This is the case for chronic granulomatous disease (CGD), a primary immunodeficiency, characterized by deficient antimicrobial activity in phagocytic cells. Several attempts to correct CGD by gene transfer in combination with bone marrow conditioning have resulted in low-level long-term engraftment and transient clinical benefits despite high levels of gene marking and high numbers of reinfused cells. This review summarizes the data from clinical trials for CGD and provides some insights into treatment options that may lead to a successful application of gene therapy for CGD.

Hematopoietic stem cell transplantation for chronic granulomatous disease

Chronic granulomatous disease (CGD) is a primary immunodeficiency disease that is caused by the lack of 1 of 5 subunits of the superoxide-producing nicotinamide adenine dinucleotide phosphate oxidase of neutrophils, macrophages, and eosinophils. Allogeneic hematopoietic stem cell transplantation (HSCT) is currently the only curative treatment for CGD and can be offered to selected patients. Improved outcome with supportive care and high clinical variability in the disease course, however, make selection of eligible patients for HSCT difficult. This article addresses recent progress in HSCT for CGD, delineates present limitations, and points to future developments.

Bone marrow transplantation for primary immunodeficiency diseases

Advances in immunology have led to a breathtaking expansion of recognized primary immunodeficiency diseases (PID) with over 120 disease-related genes identified. In North America alone more than 1000 children have received allogeneic blood or marrow transplant over the past 30 years, with the majority surviving long term. This review presents results and highlights challenges and notable advances, including novel less toxic conditioning regimens, to transplant the more common and severe forms of PID. HLA-matched sibling donors remain the ideal option, however, advances in living donor unrelated HSCT and banked umbilical cord blood grafts provide hope for all children with severe PID.