Mutations in RAB27A cause Griscelli syndrome associated with haemophagocytic syndrome

Griscelli syndrome (GS, MIM 214450), a rare, autosomal recessive disorder, results in pigmentary dilution of the skin and the hair, the presence of large clumps of pigment in hair shafts and an accumulation of melanosomes in melanocytes. Most patients also develop an uncontrolled T-lymphocyte and macrophage activation syndrome (known as haemophagocytic syndrome, HS), leading to death in the absence of bone-marrow transplantation. In contrast, early in life some GS patients show a severe neurological impairment without apparent immune abnormalities. We previously mapped the GS locus to chromosome 15q21 and found a mutation in a gene (MYO5A) encoding a molecular motor in two patients. Further linkage analysis suggested a second gene associated with GS was in the same chromosomal region. Homozygosity mapping in additional families narrowed the candidate region to a 3.1-cM interval between D15S1003 and D15S962. We detected mutations in RAB27A, which lies within this interval, in 16 patients with GS. Unlike MYO5A, the GTP-binding protein RAB27A appears to be involved in the control of the immune system, as all patients with RAB27A mutations, but none with the MYO5A mutation, developed HS. In addition, RAB27A-deficient T cells exhibited reduced cytotoxicity and cytolytic granule exocytosis, whereas MYO5A-defective T cells did not. RAB27A appears to be a key effector of cytotoxic granule exocytosis, a pathway essential for immune homeostasis.

Polymorphism of the fourth component of complement in Turks

An analysis of polymorphism in the fourth component of human complement (C4) was performed on EDTA-plasma from 142 unrelated, randomly selected Turks without collagen-vascular disease or recurrent infections. Plasma samples treated with neuraminidase and carboxypeptidase-B were subjected to high-voltage agarose gel electrophoresis followed by immunofixation. C4B allotypes were further detected in some samples by Western blots with monoclonal antibody 1228 (anti-C4B/Ch1 reactivity). The frequencies of C4A and C4B alleles were determined. Allele C4B*5, which has been found to be relatively common in Asian (Oriental) populations, was not detected in this study. No specific predilection could be noted among the rare variants. C4A*3-C4B*1 was the most common haplotype (n = 40/142, or 28%) but was found less frequently than in Caucasian populations. This finding may be the result of the limited number of samples examined. C4A and/or C4B null allotypes were seen in 49 of 142 (34.6%) subjects. The most frequent C4 null allotype seen was C4B null (37/142, or 26%): 28 subjects had one C4B null allele; 1 had a homozygous deficiency of C4B (C4B*QO, *QO) and 7 had C4A*QO C4B*QO, a double heterozygous haplotype. Frequencies of homozygous haplotype C4A*Q0-C4B*Q0 in the population studied were found to be 0.007. The results of this study demonstrate that the genetic composition of the Turkish population exhibits both similarities and differences with the European population, and ranges between Caucasian and Mongoloid (Asian) populations.

Isolated cutaneous response to granulocyte-monocyte colony stimulating factor in fatal idiopathic disseminated Bacillus-Calmette-Guerin infection

Severe disseminated Bacillus-Calmette-Guerin (BCG) infection is very rare and has been regarded as idiopathic when no immunodeficiency is present. This entity seems to be due to several new types of inherited abnormalities in the pathways important in defence against Mycobacteria. Although improvement with interferon-gamma (IFN-gamma) has been reported in some patients, to our knowledge there are no reports on the effect of other cytokines in the treatment of these patients. We report here the clinical response to IFN-gamma and granulocyte-monocyte colony stimulating factor (GM-CSF) treatment in a patient with idiopathic disseminated BCG infection who failed to respond to multiple antimycobacterial agents. The patient showed partial and transitory response to IFN-gamma, however, GM-CSF treatment led to rapid improvement of skin lesions within 2 weeks without any effect on the progression of the disease in the other organ systems.

CONCLUSION

The response of idiopathic disseminated Bacillus-Calmette-Guerin infection to granulocyte-monocyte colony stimulating factor treatment was limited to cutaneous lesions. Granulocyte-monocyte colony stimulating factor may have acted to promote wound healing or the levels of this factor achieved in other affected organs may have been inadequate.

Two genes are responsible for Griscelli syndrome at the same 15q21 locus

Griscelli syndrome is a rare autosomal recessive disease characterized by pigment dilution, variable cellular immunodeficiency, and an acute phase of uncontrolled T lymphocyte and macrophage activation. We previously mapped the disease locus to 15q21 and showed that a MyoVa gene (HGMW-approved symbol MYO5A) defect leads to Griscelli syndrome. We report a second MyoVa mutation in a new patient, confirming this first finding. However, in four other Griscelli syndrome patients analyzed, the MYOVA protein is expressed, and no mutation can be detected in the MyoVa gene coding sequence, even in the alternatively spliced region for which exon-intron boundaries were characterized. Linkage analysis performed in 15 Griscelli families thus far studied confirms the first localization. However, fine haplotype analysis in three families strongly suggests the existence of a second gene at the same locus for Griscelli syndrome less than 7.3 cM distant from the MyoVa gene.

Cyclic neutropenia complicated by renal AA amyloidosis

Cyclic neutropenia is a rare disease characterized by regular cyclic fluctuations in the numbers of neutrophils. Patients with the disease suffer from recurrent infections at regular intervals of nearly three weeks. Recently, recombinant human granulocyte colony-stimulating factor (rhG-CSF) was reported to be an effective treatment for this disease. here we describe 17-year-old cyclic neutropenic female patient with a very rare association of renal amyloidosis of AA type who was under intermittent rhG-CSF treatment for the previous one and a half years. We conclude that although the disorder is usually benign, reactive amyloidosis may rarely develop in cases who remain untreated for a long period of time. However familial Mediterranean fever (FMF) type II should also be born in mind, particularly in predisposed populations.

Mutations in Igalpha (CD79a) result in a complete block in B-cell development

Mutations in Btk, mu heavy chain, or the surrogate light chain account for 85-90% of patients with early onset hypogammaglobulinemia and absent B cells. The nature of the defect in the remaining patients is unknown. We screened 25 such patients for mutations in genes encoding components of the pre-B-cell receptor (pre-BCR) complex. A 2-year-old girl was found to have a homozygous splice defect in Igalpha, a transmembrane protein that forms part of the Igalpha/Igbeta signal-transduction module of the pre-BCR. Studies in mice suggest that the Igbeta component of the pre-BCR influences V-DJ rearrangement before cell-surface expression of mu heavy chain. To determine whether Igalpha plays a similar role, we compared B-cell development in an Igalpha-deficient patient with that seen in a mu heavy chain-deficient patient. By immunofluorescence, both patients had a complete block in B-cell development at the pro-B to pre-B transition; both patients also had an equivalent number and diversity of rearranged V-DJ sequences. These results indicate that mutations in Igalpha can be a cause of agammaglobulinemia. Furthermore, they suggest that Igalpha does not play a critical role in B-cell development until it is expressed, along with mu heavy chain, as part of the pre-BCR.

Successful bone marrow transplantation in a case of Griscelli disease which presented in accelerated phase with neurological involvement

Griscelli disease (GD) is a rare disorder characterized by pigment dilution, immunodeficiency and occurrence of accelerated phase consisting of hemophagocytosis, pancytopenia and neurological manifestations. Allogeneic BMT in the early period is an important modality of treatment for GD. We carried out an alloBMT from an HLA-identical sibling donor on a 4-year-old girl who presented in accelerated phase with neurological manifestations including convulsions, strabismus, severe dysarthria, ataxia and clonus. She was treated with etoposide, methylprednisolone and intrathecal methotrexate for 8 weeks and underwent alloBMT after receiving a conditioning regimen including ATG (rabbit, 10 mg/kg x 5 days), Bu/Cy. 8 x 108/kg nucleated bone marrow cells were given. Engraftment occurred early and the post-BMT period was uneventful. Currently, she is at 18 months post BMT with sustained engraftment and with a normal neurological examination except for minimal clonus. Long-term follow-up will determine the prognosis regarding the neurological findings.

Altered apoptotic profiles in irradiated patients with increased toxicity

PURPOSE

A retrospective study of radiation-induced apoptosis in CD4 and CD8 T-lymphocytes, from 12 cancer patients who displayed enhanced toxicity to radiation therapy and 9 ataxia telangiectasia patients, was performed to test for altered response compared to healthy blood-donors and normal cancer patients.

METHODS AND MATERIALS

Three milliliters of heparinized blood from each donor was sent via express post to the Paul Scherrer Institute (PSI) for subsequent examination. The blood was diluted 1:10 in RPMI medium, irradiated with 0-, 2-, or 9-Gy X-rays, and incubated for 48 h. CD4 and CD8 T-lymphocytes were then labeled using FITC-conjugated antibodies, erythrocytes were lysed, and the DNA stained with propidium iodide. Subsequently, cells were analyzed using a Becton Dickinson FACScan flow cytometer. Radiation-induced apoptosis was recognized in leukocytes as reduced DNA content attributed to apoptosis-associated changes in chromatin structure. Apoptosis was confirmed by light microscopy, electron microscopy, and by the use of commercially available apoptosis detection kits (in situ nick translation and Annexin V). Data from hypersensitive individuals were compared to a standard database of 105 healthy blood-donors, and a database of 48 cancer patient blood donors who displayed normal toxicity to radiation therapy. To integrate radiosensitivity results from CD4 and CD8 T-lymphocytes after 2 and 9 Gy, z-score analyses were performed.

RESULTS

A cohort of 12 hypersensitive patients was evaluated; 8 showed enhanced early toxicity, 3 showed enhanced late toxicity, and 1 showed both. The cohort displayed less radiation-induced apoptosis (-1.8 sigma) than average age-matched donors. A cohort of 9 ataxia telangiectasia homozygotes displayed even less apoptosis (-3.6 sigma).

CONCLUSION

The leukocyte apoptosis assay appears to be a useful predictor of individuals likely to display increased toxicity to radiation therapy; however, validation of this requires a prospective study.

Impaired IgG antibody production to pneumococcal polysaccharides in patients with ataxia-telangiectasia

Various factors seem to be etiologic in the susceptibility to sinopulmonary infections in ataxia-telangiectasia (A-T) patients, i.e., low serum and salivary IgA, low serum IgG2, and even aspiration of saliva. S. pneumoniae is a common pathogen responsible from pulmonary infections and impaired antibody response to polysaccharide antigens is seen in patients with IgG2 and IgA deficiency as well as patients with CVID and WAS. We studied IgG-type antibody production to six pneumococcal serotypes in 29 A-T patients by ELISA before and 3-4 weeks after pneumococcal vaccine. The response was considered positive when the antibody titer was >10 U/ml but weak when the titer was 10-20 U/ml. Twenty-two of 29 (76%) patients did not respond to any of the serotypes, 5 (17%) showed a positive response to one serotype, 1 (3.4%) to two serotypes, and 1 (3.4%) to four serotypes. With conversion to gravimetric units (ng IgG/ml) and >1800 ng/ml (300 ng Ab N/ml) considered a positive response, 5 of 29 (17.2%) patients showed a positive response (300 ng ab N/ml) to two or fewer serotypes. All patients tested produced IgG antibody to tetanus toxoid. Sixteen of 27 (59.3%) patients had low IgG2 and four (14.8%) had low IgG3 levels, while 18 (62.1%) of 29 patients had low serum IgA. No correlation was found either between serum Ig isotype levels and antipolysaccharide antibody response or between susceptibility to infection and antibody production. The mechanism responsible for disturbed antipolysaccharide (TI-2 antigen) antibody production in patients with A-T needs to be investigated. It may provide additional information on the function of the ATM gene product and be helpful in clarifying the role of B cells and contribution of T cells in TI-2 responses.

Alopecia universalis in a patient with common variable immunodeficiency

A 12-year-old boy with common variable immunodeficiency (CVI) who developed severe alopecia is presented. His sister also had alopecia and recurrent infections and died of lung infection at the age of 7 years. The loss of hair in both children was total; the pathology of a scalp skin biopsy specimen was typical for alopecia areata. The boy was subjected to clinical and immunologic evaluation and the results were compatible with common variable immunodeficiency.

Gastric antral stricture in a patient with chronic granulomatous disease

Chronic granulomatous disease (CGD) is a rare disorder of phagocytic cell oxidative metabolism. Patients have recurrent infections with catalase-positive organisms and granulomatous lesions throughout the body. Gastric antrum can be an occult site of involvement. We describe a four-year old boy with chronic granulomatous disease who was admitted with the complaints of persistent vomiting and weight loss. Gastric antral narrowing was diagnosed according to radiological findings. Treatment with steroid and antibiotics yielded a good clinical response in 15 days with a relief of the obstruction. This case report emphasizes the beneficial effect of this form of therapy in preventing life-threatening obstruction of vital organs in CGD.

Congenital erythropoietic porphyria successfully treated by allogeneic bone marrow transplantation

The long-term biochemical and clinical effectiveness of allogenic bone marrow transplantation (BMT) was shown in a severely affected, transfusion-dependent 18-month-old female with congenital erythropoietic porphyria (CEP), an autosomal recessive inborn error of heme biosynthesis resulting from mutations in the uroporphyrinogen III synthase (URO-synthase) gene. Three years post-BMT, the recipient had normal hemoglobin, markedly reduced urinary porphyrin excretion, and no cutaneous lesions with unlimited exposure to sunlight. The patient was homoallelic for a novel URO-synthase missense mutation, G188R, that expressed less than 5% of mean normal activity in Escherichia coli, consistent with her transfusion dependency. Because the clinical severity of CEP is highly variable, ranging from nonimmune hydrops fetalis to milder, later onset forms with only cutaneous lesions, the importance of genotyping newly diagnosed infants to select severely affected patients for BMT is emphasized. In addition, the long-term effectiveness of BMT in this patient provides the rationale for future hematopoietic stem cell gene therapy in severely affected patients with CEP.

Restructuring the primary health care services and changing profile of family physicians in Turkey

A new health-reform process has been initiated by Ministry of Health in Turkey. The aim of that reform is to improve the health status of the Turkish population and to provide health care to all citizens in an efficient and equitable manner. The restructuring of the current health system will allow more funds to be allocated to primary and preventive care and will create a managed market for secondary and tertiary care. In this article, we review the current and proposed primary care services models and the role of family physicians therein.

Fc gamma receptor allotypes in children with bacterial meningitis. A preliminary study

IgG2 antibody is the essential subclass to protect against encapsulated bacteria Fc gamma RIIa is the only Fc gamma receptor that interacts with human IgG2. The two genetically determined allotypes of human Fc gamma RIIa, Fc gamma RIIa-R131 and Fc gamma RIIa-H131 alleles have functionally different reactivities with IgG2 in vitro, and H/H-131 cells have markedly higher binding affinity for human IgG2. Homozygous Fc gamma RIIIb-NA1/NA1 PMNLs show higher phagocytic capacity than Fc gamma RIIIb-NA2/NA2 PMNLs. To evaluate in vivo significance of Fc gamma RIIa and Fc gamma RIIIb allotypes, we analyzed Fc gamma R allotypes in children with bacterial meningitis due to Haemophilus influenzae type b, Streptococcus pneumoniae and Neisseria meningitidis. Fc gamma RII and Fc gamma RIIIb polymorphisms were determined by using quantitative flow cytometry. Fc gamma RIIa were studied in 23 children with bacterial meningitis and 50 healthy Turkish controls, and Fc gamma IIIb in 18 and 43 such individuals, respectively. The distribution of Fc gamma RIIa in the healthy Turkish control group was found to be significantly different from that in the Chinese and Japanese population (p < 0.05), but similar to that of the white population in the USA and the Netherlands. No case (0%) had the Fc gamma RII-H/H-131 Fc gamma RIIIb-NA1/NA1 the corresponding figure in the controls was 4 (9.3%). Homozygous Fc gamma RIIa-H/H-131 phenotype was underrepresented with borderline significance (p: 0.057) in patients below two years of age in comparison with the healthy subjects and with patients with meningitis over two years of age (p: 0.059). Although the study needs to be conducted in a large series of patients in order to draw a firm conclusion, Fc gamma RIIa polymorphism may be a contributing factor to the increased susceptibility to meningitis with encapsulated bacteria in children below two years of age.

Allogeneic bone marrow transplantation in Fanconi anemia from Turkey: a report of four cases

Bone marrow transplantation (BMT) is currently the treatment of choice for patients with Fanconi anemia (FA) if a suitable donor is available. Four children with FA underwent allogeneic BMT from HLA-identical siblings during the period from 1995 to 1996. Pretransplant conditioning was Cyclophosphamide (Cy) (20 mg/kg) + Thoracoabdominal irradiation (TAI) (500 cGy) +/- Antithymocyte globulin (ATG) (2 mg/kg/day x 3). Cyclosporin A (CsA) was used as GvHD prophylaxis. The time of neutrophil (ANC>500) and platelet (>50,000) recovery were at 11-14 and 17-25 days, respectively. One patient with a pretransplant history of multiple transfusions experienced graft rejection and died at day +29 with infection and bleeding. Although three patients sustained engraftment one developed donor originated acute lymphoblastic leukemia (ALL) 18 months after BMT and died with CNS hemorrhage and infection at +25 months following 7 months of chemotherapy. None of the patients developed grade 3-4 acute GvHD. Cytotoxicity included grade II mucositis in all and severe gastroenteritis in one patient. During a follow-up period of 10 months and 2 years, two patients are well with normal blood count, recovering immune function and have a Karnofsky score of 90%.

A case of chronic severe neutropenia: oral findings and consequences of short-term granulocyte colony-stimulating factor treatment

Neutropenia is an absolute decrease in the number of circulating neutrophils in the blood which results in susceptibility to severe pyogenic infections. Various oral findings such as periodontitis, alveolar bone loss and ulceration may be seen in neutropenic patients. A case is presented of a 6 year old girl with chronic, probably congenital, severe neutropenia with frequent respiratory tract infections, recurrent oral ulcerations and significant periodontal break-down resembling prepubertal periodontitis. She was given granulocyte-colony stimulating factor (G-CSF) treatment which resulted in an increase in granulocyte count within two weeks and resolution of the neutropenic ulceration. It is suggested that G-CSF together with dental care regimens is a promising treatment model in chronic severe neutropenia cases presenting with oral manifestations.

Defective serum opsonization activity in children aged 6-48 months having acute purulent otitis media

Serum opsonization of yeast (Saccharomyces) was investigated in 51 patients whose ages were between six and 48 months (median 15 months) with acute purulent otitis media and in an age-matched control group (median 13 months). Opsonization was assessed by measuring yeast particle uptake in an assay based on an electronic count of the unphagocytosed particles in serum by polymorphonuclear leukocytes. Despite normal levels of CH50 and serum immunoglobulins, a defective opsonization was determined in 13.7 percent of the patients (7 in 51). The corresponding figure was 2.9 percent in 103 healthy controls (p < 0.001). On the other hand, 218 percent (5 in 23) of the children having a history of recurrent purulent otitis media showed defective opsonization (p < 0.001). Previously, the presence of an opsonization defect has been linked to low levels of mannan binding lectin (MBL), a calcium dependent serum lectin that acts as an opsonin. Therefore, our findings indirectly support the idea that MBL has an important role as host defense, particularly in the earlier period of life when the antibody repertoire is restricted.

Development of systemic lupus erythematosus in a patient with selective complete C1q deficiency

A 7-year-old male with recurrent erythematous and desquamated skin lesions and respiratory infections was diagnosed as selective complete C1q deficiency following detailed studies of the complement system. His asymptomatic sister also had selective complete C1q deficiency. During a follow up period of 3 years, his skin lesions persisted, he suffered from recurrent bronchopneumonias and glomerulonephritis developed. Renal function deteriorated with the appearance of anti-DNA antibodies. Renal biopsy was consistent with systemic lupus erythematosus. The patient was treated with immunosuppressive drugs, but died of renal failure. It is postulated that in this patient defective clearance of antigen-antibody complexes by the reticulo-endothelial system resulted in progressive renal disease as observed in other complement deficiencies. A retrospective molecular study disclosed a point mutation in the ClqA chain gene in a heterozygous state in parents and two siblings; in a homozygous state in the asymptomatic sister. The reason why some individuals with this defect are asymptomatic is not known at present. Diagnosis of heterozygotes by molecular studies is extremely important to give genetic counselling to the family.

CONCLUSION

Patients with recurrent infections, erythematous desquamative skin lesions, malar rash and oral mucosal involvement should be screened for complement C1q deficiency.

Dyskeratosis congenita: unusual onset with isolated neutropenia at an early age

A 3.5 year old male patient with dyskeratosis congenita (DC) presented at the age of 13 months with isolated neutropenia preceding characteristic skin findings. The average absolute neutrophil count of 500/mm3 persisted without the presence of anemia or thrombocytopenia during the follow up. Neutropenia responded to granulocyte-colony stimulating factor (G-CSF) at a dose of 10 micrograms/kg per day. Immunologic findings were normal as was the chromosomal stability and sister chromatid exchange.

Homozygous C2 deficiency: association with defective alternative pathway function and immunoglobulin deficiency

Deficiency in the second component of complement (C2) is the most common homozygous complement deficiency. While approximately half of the affected individuals are apparently healthy, C2 deficiency may be associated with autoimmune diseases and rarely increased susceptibility to infection. We report 5 patients who had homozygous type I C2 deficiency in two families. Three of them suffered from frequent infections. These symptomatic patients had additional risk factors; the index cases in the first and the second family had IgG2 deficiency and IgA deficiency, respectively, and alternative complement pathway hemolytic activity was also low in both of them and in the sibling of the first index case. These results emphasize the probable role of other immunologic defects in the clinical presentation of C2 deficiency.