Anders Åhlin

Chronic Granulomatous Disease: The European Experience

CGD is an immunodeficiency caused by deletions or mutations in genes that encode subunits of the leukocyte NADPH oxidase complex. Normally, assembly of the NADPH oxidase complex in phagosomes of certain phagocytic cells leads to a “respiratory burst”, essential for the clearance of phagocytosed micro-organisms. CGD patients lack this mechanism, which leads to life-threatening infections and granuloma formation. However, a clear picture of the clinical course of CGD is hampered by its low prevalence (∼1∶250,000). Therefore, extensive clinical data from 429 European patients were collected and analyzed. Of these patients 351 were males and 78 were females. X-linked (XL) CGD (gp91phox deficient) accounted for 67% of the cases, autosomal recessive (AR) inheritance for 33%. AR-CGD was diagnosed later in life, and the mean survival time was significantly better in AR patients (49.6 years) than in XL CGD (37.8 years), suggesting a milder disease course in AR patients. The disease manifested itself most frequently in the lungs (66% of patients), skin (53%), lymph nodes (50%), gastrointestinal tract (48%) and liver (32%). The most frequently cultured micro-organisms per episode were Staphylococcus aureus (30%), Aspergillus spp. (26%), and Salmonella spp. (16%). Surprisingly, Pseudomonas spp. (2%) and Burkholderia cepacia (<1%) were found only sporadically. Lesions induced by inoculation with BCG occurred in 8% of the patients. Only 71% of the patients received antibiotic maintenance therapy, and 53% antifungal prophylaxis. 33% were treated with γ-interferon. 24 patients (6%) had received a stem cell transplantation. The most prominent reason of death was pneumonia and pulmonary abscess (18/84 cases), septicemia (16/84) and brain abscess (4/84). These data provide further insight in the clinical course of CGD in Europe and hopefully can help to increase awareness and optimize the treatment of these patients.

Prevalence, genetics and clinical presentation of chronic granulomatous disease in Sweden

To estimate the prevalence of chronic granulomatous disease (CGD) in Sweden, an inquiry asking for known and possible CGD cases was mailed to paediatric, internal medicine and infectious disease departments all over Sweden. The detected patients were characterized as to genetics and the clinical presentation. Twenty–one patients (belonging to 16 different families) were found, corresponding to a prevalence of ∼ 1/450 000 individuals. The patients with X–linked disease, lacking a functional gp91phox protein (n= 12), comprised 57% and 43% of the patients had an autosomal recessive (AR) disease lacking p47phox (n= 7) or p67phox (n=1), respectively. All unrelated patients with X–linked disease displayed different gene abnormalities such as point mutations predicting nonsense (n= 3), missense (n= 1) or splice site mutations (n = 2), but also a total deletion and a unique 40 base pair duplicature insertion. The patients with p47phox–deficiency showed a GT deletion at a GTGT tandem repeat, and the p67phox–deficient patient displayed a heterozygous in–frame deletion of AAG combined with a large deletion in the other allele. Three patients died during the study period, two from Pseudomonas cepacia infections. Patients with X–linked disease had more frequent infections (mean of 1.7 per year), than the patients with AR inheritance (0.5 infections per year). The most common infections were dermal abscesses (n=111), followed by lymphadenitis (n=82) and pneumonias (n=73). Inflammatory bowel disease–like symptoms, mimicking Crohns disease of the colon, was seen in three CGD patients.

Molecular basis of hereditary C1q deficiency—revisited: identification of several novel disease-causing mutations

C1q is the central pattern-recognition molecule in the classical pathway of the complement system and is known to have a key role in the crossroads between adaptive and innate immunity. Hereditary C1q deficiency is a rare genetic condition strongly associated with systemic lupus erythematosus and increased susceptibility to bacterial infections. However, the clinical symptoms may vary. For long, the molecular basis of C1q deficiency was ascribed to only six different mutations. In the present report, we describe five new patients with C1q deficiency, present the 12 causative mutations described till now and review the clinical spectrum of symptoms found in patients with C1q deficiency. With the results presented here, confirmed C1q deficiency is reported in 64 patients from at least 38 families.

Involvement of a functional NADPH oxidase in neutrophils and macrophages during programmed cell clearance: implications for chronic granulomatous disease

Resolution of inflammation requires clearance of activated neutrophils by macrophages in a manner that prevents injury to adjacent tissues. Surface changes, including phosphatidylserine (PS) exposure, may target neutrophils for phagocytosis. In this study, we show that externalization of PS is defective in phorbol myristate acetate (PMA)-activated neutrophils obtained from chronic granulomatous disease (CGD) patients with mutations in components of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. Moreover, activated neutrophils from CGD patients failed to undergo clearance upon cocultivation with macrophages from normal donors. In line with these results, treatment of donor neutrophils with diphenyleneiodonium (DPI), an inhibitor of NADPH oxidase, blocked PMA-induced PS oxidation and externalization and prevented their engulfment by macrophages. Furthermore, primary macrophages from CGD patients or human gp91(phox)-deficient PLB-985 cells differentiated into macrophage-like cells were defective for engulfment of apoptotic target cells. Pretreatment of normal macrophages with DPI also suppressed the subsequent ingestion of PS-positive target cells. Together, these data demonstrate that NADPH oxidase plays an important role in the process of macrophage disposal of target cells (programmed cell clearance). Thus we speculate that the lack of a functional NADPH oxidase results in impaired neutrophil clearance and the exaggerated inflammation that is characteristic for CGD.

Chronic granulomatous disease – haematopoietic stem cell transplantation versus conventional treatment

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.

Efficacy and safety of two different rG-CSF preparations in the treatment of patients with severe congenital neutropenia*

In patients with severe congenital neutropenia (SCN), the absolute neutrophil count (ANC) is raised during treatment with granulocyte colony‐stimulating factor (G‐CSF), resulting in a marked reduction of bacterial infection. Some patients, however, still have recurrent but less severe bacterial infections and severe periodontal infections. As it has been suggested that the biological activity of glycosylated recombinant human G‐CSF (rHuG‐CSF, i.e. lenograstim) is higher than the non‐glycosylated form (i.e. filgrastim), we compared the two given in equimolar doses. Seven SCN patients participated in an open, randomized, double crossover study comprising 60 weeks, with four 12‐week periods when the two drugs alternated after a 12‐week run‐in‐period. The mean ANC values, sampled every second week, were 5·1 × 109/l during filgrastim treatment and 4·2 × 109/l during lenograstim treatment (P = 0·042). The ANC levels were also significantly higher during filgrastim treatment, when comparing each complementary pair of ANC measurements (P = 0·011) as well as the mean ANC values during each 12‐week treatment period (P = 0·033). There were no differences regarding the frequency of infection, antibiotic treatment, gingival bleeding and the number of hospital admissions between the groups. We conclude that filgrastim and lenograstim displayed equal clinical efficacy, but that ANC levels were higher during filgrastim treatment, when administered in equimolar doses.

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

Purpose of reviewWe 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 findingsAzole 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. SummarySeveral 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.

Marked variability in clinical presentation and outcome of patients with C1q immunodeficiency.

OBJECTIVE Globally approximately 60 cases of C1q deficiency have been described with a high prevalence of Systemic Lupus Erythematosus (SLE). So far treatment has been guided by the clinical presentation rather than the underlying C1q deficiency. Recently, it was shown that C1q production can be restored by allogeneic hematopoietic stem cell transplantation. Current literature lacks information on disease progression and quality of life of C1q deficient persons which is of major importance to guide clinicians taking care of patients with this rare disease. METHODS We performed an international survey, of clinicians treating C1q deficient patients. A high response rate of >70% of the contacted clinicians yielded information on 45 patients with C1q deficiency of which 25 are published. RESULTS Follow-up data of 45 patients from 31 families was obtained for a median of 11 years after diagnosis. Of these patients 36 (80%) suffer from SLE, of which 16 suffer from SLE and infections, 5 (11%) suffer from infections only and 4 (9%) have no symptoms. In total 9 (20%) of the C1q deficient individuals had died. All except for one died before the age of 20 years. Estimated survival times suggest 20% case-fatality before the age of 20, and at least 50% of patients are expected to reach their middle ages. CONCLUSION Here we report the largest phenotypic data set on C1q deficiency to date, revealing high variance; with high mortality but also a subset of patients with an excellent prognosis. Management of C1q deficiency requires a personalized approach.

Allogeneic Hematopoietic Stem Cell Transplantation in the Treatment of Human C1q Deficiency: The Karolinska Experience.

Background Human C1q deficiency is associated with systemic lupus erythematosus (SLE) and increased susceptibility to severe bacterial infections. These patients require extensive medical therapy and some develop treatment-resistant disease. Because C1q is produced by monocytes, it has been speculated that allogeneic hematopoietic stem cell transplantation (allo-HSCT) may cure this disorder. Methods We have so far treated 5 patients with C1q deficiency. In 3 cases, SLE symptoms remained relatively mild after the start of medical therapy, but 2 patients developed treatment-resistant SLE, and we decided to pursue treatment with allo-HSCT. For this purpose, we chose a conditioning regimen composed of treosulfan (14 g/m2) and fludarabine (30 mg/m2) started on day −6 and given for 3 and 5 consecutive days, respectively. Thymoglobulin was given at a cumulative dose of 8 mg/kg, and graft-versus-host disease prophylaxis was composed of cyclosporine and methotrexate. Results A 9-year-old boy and a 12-year-old girl with refractory SLE restored C1q production after allo-HSCT. This resulted in normal functional properties of the classical complement pathway followed by reduced severity of SLE symptoms. The boy developed posttransplant lymphoproliferative disease, which resolved after treatment with rituximab and donor lymphocyte infusion. Unfortunately, donor lymphocyte infusion induced severe cortisone-resistant gastrointestinal graft-versus-host disease, and the patient died from multiple organ failure 4 months after transplantation. The girl is doing well 33 months after transplantation, and clinically, all signs of SLE have resolved. Conclusions Allo-HSCT can cure SLE in human C1q deficiency and should be considered early in subjects resistant to medical therapy.