Low-dose enzyme replacement therapy for Gaucher's disease: effects of age, sex, genotype, and clinical features on response to treatment

Although alglucerase therapy has become the treatment of choice for symptomatic patients with Gaucher's disease, the low-dose/high-frequency regimen introduced as a means to reduce the high cost of treatment has raised major controversy. We evaluated the efficacy and safety of low-dose alglucerase in 29 patients with Gaucher's disease who completed 6 to 28 months of therapy. All received intravenous alglucerase at a monthly dose of 30 units/kg, given usually in equal doses 3 times a week. All patients responded well to treatment. The hematological improvement and the reduction in organomegaly were satisfactory. No correlation was found between age, sex, genotype, previous splenectomy, or severity score index and the response to treatment. Patients with a greater degree of hepatomegaly tended to have a more pronounced decrease in liver size, although this reduction did not reach statistical significance. We confirmed that a low-dose/high-frequency regimen of alglucerase was as effective as a high-dose/low-frequency protocol in the treatment of Gaucher's disease, even in the severely ill. Whenever cost is an issue, we recommend using this low-dose regimen.

Low-dose high-frequency enzyme replacement therapy for very young children with severe Gaucher disease

Six children with a mean age of 4.6 years (range 2.5-7), suffering from severe Gaucher disease, were treated with low-dose high-frequency intravenous enzyme replacement (Ceredase, Genzyme, U.S.A.) for a period of 10-24 months. Although, in general, these patients were more severely affected than previously reported patients, the results of the treatment were as satisfactory as those obtained by using much higher doses at low frequency. In addition to regression of organomegaly and improvement of haematological abnormalities, we observed two unique clinical responses in three patients: two showed decreased tendency to bacterial infections, associated with improvement in neutrophil chemotaxis, and one patient, with type 3 Gaucher disease, showed some improvement in neurological findings. Several measures were taken to ameliorate the burden of the high-frequency treatment. These included implantation of venous access devices, establishment of a home-treatment programme and the application of effective local anaesthesia. Therefore the low-dose high-frequency protocol appears to be both an effective and feasible alternative to the costly high-dose low-frequency protocols even in very young children.

Nonrandom association of free iron with membranes of sickle and beta-thalassemic erythrocytes

To further define the nature of abnormal iron deposits on the membranes of pathologic red blood cells, we have used sickle cell anemia (HbSS), HbSC, and beta-thalassemic erythrocytes (RBCs) to prepare inside-out membranes (IOM) and insoluble membrane aggregates (AGGs) containing coclustered hemichrome and band 3. Study of IOM from HbSC and thalassemic patients showed that amounts of heme iron and, especially, free iron were much higher in patients who had undergone surgical splenectomy. The membrane AGGs from HbSS and beta-thalassemic RBCs contained much more globin than heme, with this discrepancy being variable from patient to patient. Although these AGGs were enriched (compared with the ghosts from which they were derived) for heme, as expected, less than 10% of total ghost heme was recovered in them. Remarkably, these AGGs also were enriched for nonheme iron, markedly so in some patients. Iron binding studies showed that the association of free iron with these hemichrome/band 3 AGGs is explained by the fact that free iron binds to denatured hemoglobin. These results document that free iron is nonrandomly associated with the membranes of sickle and beta-thalassemic RBCs. Whether this plays a causative role in the premature removal of such cells from the circulation remains to be seen.

Prevalence of nine mutations among Jewish and non-Jewish Gaucher disease patients

The frequency of nine different mutated alleles known to occur in the glucocerebrosidase gene was determined in 247 Gaucher patients, of whom 176 were of Jewish extraction, 2 were Jewish with one converted parent, and 69 were of non-Jewish origin. DNA was prepared from peripheral blood, active glucocerebrosidase sequences were amplified by using the PCR technique, and the mutations were identified by using the allele-specific oligonucleotide hybridization method. The N37OS mutation appeared in 69.77% of the mutated alleles in Jewish patients and in 22.86% of the mutated alleles in non-Jews. The 84GG mutation, which has not been found so far among non-Jewish patients, existed in 10.17% of the disease alleles among Jewish patients. The IVS + 1 mutation constituted 2.26% of the disease alleles among Jewish patients and 1.43% among the non-Jewish patients. RecTL, a complex allele containing four single-base-pair changes, occurred in 2.26% of the alleles in Jewish patients and was found in two (1.43%) of the patients of non-Jewish extraction. Another complex allele, designated "RecNciI" and containing three single-point mutations, appeared in 7.8% of alleles of non-Jewish patients and in only two (0.56%) of the Jewish families. The prevalence of the L444P mutation among non-Jewish Gaucher patients was 31.43%, while its prevalence among Jewish patients was only 4.24%. The prevalence of two other point mutations--D409H and R463C--was 5.00% and 3.57%, respectively, among non-Jewish patients and was not found among the Jewish Gaucher patient population. The prevalence of the R496H mutation, found so far only among Jewish patients, was 1.13%. The results presented demonstrate that seven mutations identify 90.40% of the mutations among Jewish patients and that these seven mutations allow diagnosis of only 73.52% of the non-Jewish patients. Identification of additional mutant alleles will enhance the accuracy of carrier detection.

Impaired neutrophil chemotaxis in patients with thalassaemia major

Random and directed migration, O2- production, degranulation and adhesion were studied in neutrophils obtained from patients with homozygous beta-thalassaemia and iron overload, in the presence or absence of thalassaemic serum. The only significant defect found was an impairment in directed chemotaxis, further depressed after addition of thalassaemic serum. The chemotactic defect was encountered in all the patients that have suffered from pyogenic infections except one, and was not correlated with the severity of the iron overload. It is suggested that the described neutrophil migration impairment may contribute to the tendency towards infection in certain patients with homozygous beta-thalassaemia.

Adult-type Gaucher disease in children: genetics, clinical features and enzyme replacement therapy

Clinical manifestations of type 1 (Adult) Gaucher disease usually start in childhood. However, most of the previously published data describe the features of this disorder in adults. We present the clinical and genetic characteristics of 34 children and adolescents with type 1 Gaucher disease evaluated in our clinic during the past two years. Patients were aged 2-18 years; 18 were boys and 16 girls. The majority presented before the age of 10. Growth retardation appeared as a prominent feature, with 26% in or below the third percentile in weight, and 30% so in height, especially in the youngest age group (2-5 years). Anaemia and thrombocytopenia occurred in 80% and 60% of the children, respectively. Hepatosplenomegaly was noted in all the children; only 3 were splenectomized. Skeletal involvement was evident on X-rays in 90% of the patients, but only 50% complained of bone pains. Three patients had severe bone disease, with avascular necrosis of the hip joint. Mutation analysis at the DNA level revealed the 1226/1226 genotype in 12 (35%) patients and 1226/84GG in 13 (38%). Correlation was found between the genotypes and the severity of the disease, including growth retardation. A positive response was documented in all 9 patients who completed 12 months of the recently-introduced enzyme replacement therapy for Gaucher disease.

Home treatment with intravenous enzyme replacement therapy for Gaucher disease: an international collaborative study of 33 patients

Intravenous enzyme replacement therapy (Alglucerase; Ceredase; Genzyme Corp, Boston, MA) is an effective and safe treatment for patients with type 1 Gaucher disease. In an attempt to reduce its high cost, a "low-dose high-frequency" protocol (30 U/kg/mo, 3 times a week) was introduced and found to be as effective as the original high-dose protocol (60 U/kg every 2 weeks). Because receiving frequent infusions creates a burden for many patients, we have implemented a program of home treatment for our patients. We now report the safety and feasibility of low-dose/high-frequency home intravenous enzyme-replacement therapy in 33 patients with Gaucher disease. The chronic nature of the treatment, its safety, lack of adverse effects, the stable condition of most patients, and the need to reduce the high cost make enzyme replacement for Gaucher disease a good candidate for intravenous home therapy.

Correction of neutrophil chemotaxis defect in patients with Gaucher disease by low-dose enzyme replacement therapy

We have recently described a chemotactic defect in severely afflicted Gaucher disease patients. Two of the patients were treated with low-dose intravenous enzyme replacement (Ceredase). Marked improvement in their hematological status, organomegaly, and growth was observed. In addition, their chemotactic defect and their tendency towards infections were corrected within 1 year of treatment.

Abnormal neutrophil chemotaxis in Gaucher disease

The tendency towards infection described in Gaucher disease patients has been attributed to their post-splenectomy state. We noticed that certain patients with intact spleen have also suffered from recurrent pyogenic infections, thus an attempt to study their neutrophil function has been made. Nine of 29 patients studied expressed significant decrease in neutrophil chemotaxis directed towards zymosan activated serum or N-formyl-methionyl-leucyl-phenylalanine. Random migration was significantly impaired in five of those nine patients. Adherence of neutrophils to nylon fibres and O2- production were intact. The patients with impaired chemotaxis were significantly afflicted by their disease (early onset of symptoms and severity score index > 10) and most of them had genotypes associated with severe disease (1448/1448 and 1226/84GG). No correlation was found with the spleen status. Three of the patients with impaired chemotaxis, and none of the patients with normal neutrophil function, suffered from recurrent pyogenic infections. It is suggested that the described neutrophil migration impairment may contribute to the tendency towards infection in certain patients with advanced Gaucher disease.

Absence of natural killer cells in a child with pure red blood cell aplasia

A 16-year old boy was known to suffer from red blood cell (RBC) aplasia from the age of 4 years. Peripheral blood lymphocytes (PBL) from the patient were found to lack natural killer (NK) cytotoxic activity, even after stimulation with alpha-interferon. His PBL also lacked Leu-7+ and Leu-11+ cells, although his granulocytes showed normal expression of the Leu-11 marker. The lack of NK cells did not seem to result from the various immunosuppressive treatments he received, since the NK deficiency was noted 2 years after he stopped receiving such treatment. The possibility is discussed that lack of NK cells may lead to the development of RBS aplasia if NK cells play a role in promoting the production of RBC.

Natural course of atrial septal aneurysm in children and the potential for spontaneous closure of associated septal defect

Atrial septum aneurysm (ASA), usually involving the region of the fossa ovalis, has rarely been described in children. In this study, the incidence and natural course of this anomaly were prospectively evaluated in 3,500 children referred for echocardiographic examination. ASA was found in 35 patients, 19 female and 16 male (1.0%). Patients were 6 years of age or younger at the time of diagnosis and 18 were neonates. None of the 750 children with normal echocardiograms had ASA. The most common associated lesion was atrial septal defect (ASD), which occurred in 24 of the 35 patients (69%). Other associated cardiac lesions were ventricular septal defect in 10, pulmonary stenosis in 5, patient ductus arteriosus in 4 and coarctation or interruption of the aorta with subaortic membrane in 2. No clinical complications were associated with ASA. Six patients with complex heart disease died. When associated with ASD, the direction of the ASA motion and that of the shunt found by Doppler echocardiography were similar. Fourteen patients with ASD were followed for 0.5 to 4 years. In 8 the ASD closed and in 6 the ASA disappeared. In 6 patients the ASD and ASA persisted until the end of the follow-up (p less than 0.01). Thus, the incidence of ASA in children in this series was higher than previously presumed and usually was associated with other cardiac anomalies, mainly ASD. In children, ASA tends to disappear with age and may have a role in spontaneous closure of associated ASD.

Chronic pigmented purpura: a case report of Schamberg's disease

The syndrome of chronic pigmented purpura (CPP) consists of pigmented macular lesions, predominantly involving the lower extremities. An 11-year-old girl was diagnosed initially as suffering from vasculitic purpura, but the clinical course and the skin histology proved to be consistent with CPP. This syndrome should be included in the differential diagnosis of childhood purpura.

Impaired kinetic properties of hypoxanthine-guanine phosphoribosyl transferase as a cause of uric acid nephropathy in early infancy

A 6-month-old infant presented with failure to thrive, hyperuricaemia and renal insufficiency. The hyperuricaemia was due to uric acid over-production. The level of hypoxanthine-guanine phosphoribosyltransferase (HGPRT) activity was found to be normal. However, a two-fold increase in the Km of the enzyme to hypoxanthine as well as in the Vmax values was observed. It seems therefore, that in cases of uric acid over-production, screening tests of HGPRT activity may be insufficient and additional kinetic properties of the enzyme should be tested.

Transient hyperphosphatasemia of infancy

Very high serum levels of alkaline phosphatase were found in four children aged 13 to 24 months. No other abnormalities nor explanation for the raised enzyme levels were found. The origins of the elevated enzyme levels were shown by isoenzyme studies to be the liver in one case, the bone in two cases, and undetermined in one case. Serum alkaline phosphatase levels returned to normal after periods of 5 to 20 weeks. Awareness of these benign forms of hyperphosphatasemia will aid the physician in the differential diagnosis of elevated alkaline phosphatase levels.

Congenital isolated folic acid malabsorption

We report a case of congenital isolated malabsorption of folic acid, the first in a boy. Only seven previous cases have been reported, and we discuss two aspects--namely, the tendency to infection, with evidence of impairment of both cellular and humoral immunity, and the absence of neurological disturbances.

Prostaglandins in disorders of the intestinal tract: a review

Prostaglandins (PGs) are natural oxygenated products of polyunsaturated fatty acids. They have multiple effects on the gastrointestinal tract. Their major physiological roles in the intestine are the promotion of solute and water secretion and the control of bowel motility. Prostaglandins have a role in the pathogenesis of diarrhea in a wide spectrum of gastrointestinal disorders. The effects and the potential contribution of PGs in various gastrointestinal disorders are discussed, and therapeutic modalities in these disorders are reviewed.

Hypercalcemia in acute lymphatic leukemia

We report the case histories of 2 patients with a rapidly fatal form of acute lymphatic leukemia, who showed severe hypercalcemia during the acute phase of the disease. The pathogenetic mechanism of the hypercalcemia in these two cases was different. A short review of present day theories regarding the pathogenesis of tumor hypercalcemia is presented.

Sweet syndrome in early childhood

A 21-month-old child with acute febrile dermatosis, leukocytosis and skin biopsy showing intradermal neutrophil infiltrate was diagnosed as suffering from Sweet syndrome. This syndrome is rare in children, described heretofore in only seven paediatric patients. The clinical and histological features, differential diagnosis, as well as the potential association with more widespread systemic diseases are discussed.

Growth failure due to protein loss in dermatitis

A 10-month-old infant is described who suffered from extensive atopic dermatitis, failure to thrive, hypoalbuminaemia and oedema. Large amounts of sticky exudate were lost through the skin and were shown to be rich in albumin. As renal and intestinal loss of protein was excluded, the patient's condition was ascribed to the loss of albumin through the skin at a rate that out-stripped the synthesis of this protein. Treatment with steroids resulted in dramatic clearing of his dermatitis, and subsequent rapid correction of his hypoalbuminaemia, oedema and anaemia.