Mucopolysaccharidosis I, II, and VI: Brief review and guidelines for treatment

Mucopolysaccharidoses (MPS) are rare genetic diseases caused by the deficiency of one of the lysosomal enzymes involved in the glycosaminoglycan (GAG) breakdown pathway. This metabolic block leads to the accumulation of GAG in various organs and tissues of the affected patients, resulting in a multisystemic clinical picture, sometimes including cognitive impairment. Until the beginning of the XXI century, treatment was mainly supportive. Bone marrow transplantation improved the natural course of the disease in some types of MPS, but the morbidity and mortality restricted its use to selected cases. The identification of the genes involved, the new molecular biology tools and the availability of animal models made it possible to develop specific enzyme replacement therapies (ERT) for these diseases. At present, a great number of Brazilian medical centers from all regions of the country have experience with ERT for MPS I, II, and VI, acquired not only through patient treatment but also in clinical trials. Taking the three types of MPS together, over 200 patients have been treated with ERT in our country. This document summarizes the experience of the professionals involved, along with the data available in the international literature, bringing together and harmonizing the information available on the management of these severe and progressive diseases, thus disclosing new prospects for Brazilian patients affected by these conditions.

Outcomes after related and unrelated umbilical cord blood transplantation for hereditary bone marrow failure syndromes other than Fanconi anemia

BACKGROUND

Allogeneic stem cell transplantation is the only curative option for patients with hereditary bone marrow failure syndromes. Umbilical cord blood is an alternative source of stem cells for allogeneic transplantation.

DESIGN AND METHODS

This multicenter, retrospective study is based on data reported to the Eurocord Registry about patients with hereditary bone marrow failure syndrome who underwent umbilical cord blood transplantation.

RESULTS

Sixty-four patients with hereditary bone marrow failure syndromes were transplanted from related (n = 20) or unrelated donors (n = 44). Diagnoses were Diamond-Blackfan anemia (21 patients), congenital amegakaryocytic thrombocytopenia (16 patients), dyskeratosis congenita (8 patients), Shwachman-Diamond syndrome (2 patients), severe congenital neutropenia (16 patients) and unclassified (1 patient). In the group of patients who received grafts from related donors, all patients but one received an HLA-matched sibling transplant. The median number of total nucleated cells infused was 5 × 10⁷/kg. The cumulative incidence of neutrophil recovery at 60 days was 95%. Two patients had grade II-IV acute graft-versus-host disease, while the 2-year cumulative incidence of chronic graft-versus-host disease was 11%. The 3-year overall survival rate was 95%. In the group of patients who received grafts from unrelated donors, 86% had HLA-mismatched grafts and three received two umbilical cord blood units. The median number of total nucleated cells infused was 6.1 × 10⁷/kg. The cumulative incidence of neutrophil recovery at day 60 in this group was 55%. The 100-day cumulative incidence of grade II-IV acute graft-versus-host disease was 24%, while the 2-year cumulative incidence of chronic graft-versus-host disease was 53%. The 3-year overall survival rate was 61%; better overall survival was associated with age less than 5 years (P = 0.01) and 6.1 × 10⁷/kg or more total nucleated cells infused (P = 0.05).

CONCLUSIONS

In patients with hereditary bone marrow failure syndromes, related umbilical cord blood transplantation is associated with excellent outcomes while increasing cell dose and better HLA matching might provide better results in unrelated umbilical cord blood transplantation.

Omenn syndrome in an infant with IL7RA gene mutation

Omenn syndrome (OS) is a rare combined immunodeficiency characterized by erythroderma, lymphadenopathy, and autoimmune manifestations. Most cases are due to mutations in the RAG genes. We report a case of OS due to mutations of IL7RA, thus defining Omenn syndrome as a genetically heterogeneous condition.

Recommended screening and preventive practices for long-term survivors after hematopoietic cell transplantation

Advances in hematopoietic cell transplantation (HCT) technology and supportive care techniques have led to improvements in long-term survival after HCT. Emerging indications for transplantation, introduction of newer graft sources (eg, umbilical cord blood) and transplantation of older patients using less intense conditioning regimens have also contributed to an increase in the number of HCT survivors. These survivors are at risk for developing late complications secondary to pre-, peri-, and posttransplant exposures and risk factors. Guidelines for screening and preventive practices for HCT survivors were published in 2006. An international group of transplantation experts was convened in 2011 to review contemporary literature and update the recommendations while considering the changing practice of transplantation and international applicability of these guidelines. This review provides the updated recommendations for screening and preventive practices for pediatric and adult survivors of autologous and allogeneic HCT.

The Salivary Microbiome and Oral Cancer Risk: a Pilot Study in Fanconi Anemia

Fanconi anemia (FA) is a rare genetic disease characterized by chromosomal instability and impaired DNA damage repair. FA patients develop oral squamous cell carcinoma (OSCC) earlier and more frequently than the general population, especially after hematopoietic stem cell transplantation (HSCT). Although evidence of an etiological role of the local microbiome and carcinogenesis has been mounting, no information exists regarding the oral microbiome of FA patients. The aim of this study was to explore the salivary microbiome of 61 FA patients regarding their oral health status and OSCC risk factors. After answering a questionnaire and receiving clinical examination, saliva samples were collected and analyzed using 16S rRNA sequencing of the V3-V4 hypervariable region. The microbial profiles associated with medical and clinical parameters were analyzed using general linear models. Patients were young (mean age, 22 y) and most had received HSCT ( n = 53). The most abundant phyla were Firmicutes [mean relative abundance (SD), 42.1% (10.1%)] and Bacteroidetes [(25.4% (11.4%)]. A history of graft-versus-host disease (GVHD) ( n = 27) was associated with higher proportions of Firmicutes (43.8% × 38.5%, P = 0.05). High levels of gingival bleeding were associated with the genera Prevotella (22.25% × 20%), Streptococcus (19.83% × 17.61%), Porphyromonas (3.63% × 1.42%, P = 0.03), Treponema (1.02% × 0.28%, P = 0.009), Parvimonas (0.28% × 0.07%, P = 0.02) and Dialister (0.27% × 0.10%, P = 0.04). Finally, participants transplanted over 11 y ago showed the highest levels of Streptococcus (18.4%), Haemophilus (12.7%) and Neisseria (6.8%). In conclusion, FA patients that showed poor oral hygiene harbored higher proportions of the genera of bacteria compatible with gingival disease. Specific microbial differences were associated with a history of oral GVHD and a history of oral mucositis.

Successful Allogenic Stem Cell Transplantation in Patients with Inherited CARD9 Deficiency

Autosomal recessive (AR) CARD9 (caspase recruitment domain-containing protein 9) deficiency underlies invasive infections by fungi of the ascomycete phylum in previously healthy individuals at almost any age. Although CARD9 is expressed mostly by myeloid cells, the cellular basis of fungal infections in patients with inherited CARD9 deficiency is unclear. Therapy for fungal infections is challenging, with at least 20% premature mortality. We report two unrelated patients from Brazil and Morocco with AR CARD9 deficiency, both successfully treated with hematopoietic stem cell transplantation (HSCT). From childhood onward, the patients had invasive dermatophytic disease, which persisted or recurred despite multiple courses of antifungal treatment. Sanger sequencing identified homozygous missense CARD9 variants at the same residue, c.302G>T (p.R101L) in the Brazilian patient and c.301C>T (p.R101C) in the Moroccan patient. At the ages of 25 and 44 years, respectively, they received a HSCT. The first patient received a HLA-matched HSCT from his CARD9-mutated heterozygous sister. There was 100% donor chimerism at D + 100. The other patient received a T cell-depleted haploidentical HSCT from his CARD9-mutated heterozygous brother. A second HSCT from the same donor was performed due to severe amegakaryocytic thrombocytopenia despite achieving full donor chimerism (100%). At last follow-up, more than 3 years after HSCT, both patients have achieved complete clinical remission and stopped antifungal therapy. HSCT might be a life-saving therapeutic option in patients with AR CARD9 deficiency. This observation strongly suggests that the pathogenesis of fungal infections in these patients is largely due to the disruption of leukocyte-mediated CARD9 immunity.

Neurological complications of hematopoietic stem cell transplantation (HSCT): a retrospective study in a HSCT center in Brazil

We present the neurological complications evaluated in a series of 1000 patients who underwent hematopoietic stem cell transplantation (HSCT). Central nervous system (CNS) neurological complications, particularly brain hemorrhages, were the most common, followed by seizures and CNS infections. An unusual neurological complication was Wernicke's encephalopathy. Less frequent neurological complications were metabolic encephalopathy, neuroleptic malignant syndrome, reversible posterior leukoencephalopathy syndrome, brain infarct and movement disorders. The most common neurological complication of the peripheral nervous system was herpes zoster radiculopathy, while peripheral neuropathies, inflammatory myopathy and myotonia were very rarely found.

Engraftment and survival following hematopoietic stem cell transplantation for osteopetrosis using a reduced intensity conditioning regimen

Autosomal recessive osteopetrosis (OP) is a disease characterized by osteoclast dysfunction, leading to multisystem morbidity and death of most affected children. Hematopoietic stem cell transplantation (HSCT) is the treatment of choice for OP, but this patient population is particularly prone to post-transplant complications and death after myeloablative conditioning. To determine the potential of achieving improved overall outcomes in these patients by decreasing pre-transplant mortality, we investigated engraftment and survival following a reduced intensity regimen including busulfan, fludarabine and total lymphoid irradiation. We report outcomes in 11 patients. All six patients who received a bone marrow or peripheral stem cell graft engrafted with >75% donor chimerism. In contrast, all five recipients of unrelated cord blood as a stem cell source for a first graft failed to demonstrate donor hematopoietic chimerism. The day 100 and 6-month mortality was low at 9%. One year after HSCT, six of 11 patients (55%) were surviving. Our data suggest that this regimen results in low peri-transplant mortality without compromising engraftment when a marrow or peripheral stem cell graft is used. An umbilical cord blood graft, however, should be used with caution for patients with OP when this or a similar reduced intensity regimen is used.

Haematopoietic cell transplants in Latin America

Haematopoietic cell transplants are done by more than 1500 transplant centres in 75 countries, mostly for life-threatening haematological disorders. However, transplant technology and access are not uniformly distributed worldwide. Most transplants are done predominately in Europe, North America and some Asian countries. We review transplant activity in Latin America, a geographic region with a population of >600 million persons living in countries with diverse economic and social development levels. These data indicate a 20-40-fold lower frequency of transplants in Latin America compared with Europe and North America. We show that although economics, infrastructure and expertise are important limitations, other variables also operate. Changes in several of these variables may substantially increase transplant activity in Latin America.

Factors Associated with Long-Term Risk of Relapse after Unrelated Cord Blood Transplantation in Children with Acute Lymphoblastic Leukemia in Remission

For pediatric patients with acute lymphoblastic leukemia (ALL), relapse is an important cause of treatment failure after unrelated cord blood transplant (UCBT). Compared with other donor sources, relapse is similar or even reduced after UCBT despite less graft-versus-host disease (GVHD). We performed a retrospective analysis to identify risk factors associated with the 5-year cumulative incidence of relapse after UCBT. In this retrospective, registry-based study, we examined the outcomes of 640 children (<18 years) with ALL in first complete remission (CR1; n = 257, 40%) or second complete remission (CR2; n = 383, 60%) who received myeloablative conditioning followed by a single-unit UCBT from 2000 to 2012. Most received antithymocyte globulin (88%) or total body irradiation (TBI; 69%), and cord blood grafts were primarily mismatched at 1 (50%) or 2+ (34%) HLA loci. Considering patients in CR1, the rates of 5-year overall survival (OS), leukemia-free survival (LFS), and relapse were 59%, 52%, and 23%, respectively. In multivariate analysis (MVA), acute GVHD (grades II to IV) and TBI protected against relapse. In patients in CR2, rates of 5-year OS, LFS, and the cumulative incidence of relapse were 46%, 44%, and 28%, respectively. In MVA, longer duration from diagnosis to UCBT (≥30 months) and TBI were associated with decreased relapse risk. Importantly, receiving a fully HLA matched graft was a strong risk factor for increased relapse in MVA. An exploratory analysis of all 640 patients supported the important association between the presence of acute GVHD and less relapse but also demonstrated an increased risk of nonrelapse mortality. In conclusion, the impact of GVHD as a graft-versus-leukemia marker is evident in pediatric ALL after UCBT. Strategies that promote graft-versus-leukemia while harnessing GVHD should be further investigated.

A socioenvironmental composite index as a tool for identifying urban areas at risk of lymphatic filariasis

OBJECTIVE

To describe the spatial distribution of lymphatic filariasis and its relationship with the socioenvironmental risk indicator, thus identifying priority localities for interventions in endemic urban areas.

METHODS

The study area was the municipality of Jaboatão dos Guararapes, State of Pernambuco, Brazil. The data sources were a parasitological survey and the 2000 demographic census. From these data, a socioenvironmental composite risk indicator was constructed using the 484 census tracts (CT) as the analysis units, based on the score-formation technique. Census tracts with higher indicator values presented higher risk of occurrences of filariasis.

RESULTS

Six thousand five hundred and seven households were surveyed and 23 673 individuals were examined, among whom 323 cases of microfilaremia were identified. The mean prevalence rate for the municipality was 1.4%. The indicator showed that 73% (237/323) of the cases of microfilaremia were in high-risk areas (third and fourth quartiles) with worse socioenvironmental conditions (RR = 4.86, CI = 3.09-7.73, P < 0.05).

CONCLUSIONS

The socioenvironmental composite risk indicator demonstrated sensitivity, since it was able to identify the localities with greater occurrence of infection. Because it can stratify spaces by using official and available data, it constitutes an important tool for use in the worldwide program for eliminating lymphatic filariasis.

Cyclophosphamide-based in vivo T-cell depletion for HLA-haploidentical transplantation in Fanconi anemia

Allogeneic hematopoietic cell transplantation (HCT) is the only known cure for patients with Fanconi anemia (FA) who develop aplasia or leukemia. However, transplant regimens typically contain high-dose alkylators, which are poorly tolerated in FA patients. Furthermore, as many patients lack human leukocyte antigen (HLA)-matched family donors, alternative donors are used, which can increase the risk of both graft rejection and graft-versus-host disease (GVHD). To improve on these three concerns, we developed a multi-institutional clinical trial using a fludarabine (FLU)-based conditioning regimen with limited alkylators/low-dose radiation, HLA-haploidentical marrow, followed by reduced-dose cyclophosphamide (CY) to treat three FA patients with aplasia. All three patients engrafted with 100% donor CD3 chimerism at 1 month. One patient died early from disseminated toxoplasmosis infection. Of the two survivors, one had significant pretransplant co-morbidities and inadequate immunosuppression, and developed severe acute GVHD. The other patient had only mild acute and no chronic GVHD. With a follow-up of 2 and 3 years, respectively, both patients are doing well, are transfusion-independent, and maintain full donor chimerism. The patient with severe GVHD has resolving oral GVHD and good quality of life. We conclude that using low-intensity conditioning, HLA-haploidentical marrow, and reduced-dose CY for in vivo T-cell depletion can correct life-threatening aplasia in FA patients.

The epidemiological delimitation of lymphatic filariasis in an endemic area of Brazil, 41 years after the first recorded case

In 2002, the status of lymphatic filariasis (LF) in the district of Jaboatão, in north-eastern Brazil, was reviewed, 41 years after the first case of the disease was recorded in the area. Current data from Jaboatão were compared with older information from the district that had been published, as official reports on filariasis cases and mosquitoes and as the result of population surveys, between 1948 and 1997. Although the first microfilaria-positive cases were detected in the district in 1959, it was not until 1993 that the national Ministry of Health categorized Jaboatão as an endemic area. In 2002, fingerprick samples of blood, each of about 50 microl, were collected at night (23.00-01.00 hours) from 4365 individuals in the district and used to make thick smears. Microfilariae were detected in the smears of blood from 33 (0.8%) of the subjects, 12 of whom were considered autochthonous cases of LF. The male subjects were significantly more likely to be microfilaraemic than the female (1.1% v. 0.4%; P<0.05) but there was no direct relationship between prevalence and age, the microfilaraemics varying in age from 6-64 years. The Socorro sub-district had the highest prevalence, of 2.9%. It is recommended that the National Programme to Eliminate Filariasis uses mass drug administrations and vector control throughout the district, regardless of the prevalences recorded in the latest survey.

Therapy-related acute myeloid leukemia with KMT2A-SNX9 gene fusion associated with a hyperdiploid karyotype after hemophagocytic lymphohistiocytosis

Therapy-related acute myeloid leukemia (t-AML) following treatment with topoisomerase-II inhibitors has been increasingly reported. These compounds (e.g. etoposide) promote DNA damage and are associated with KMT2A rearrangements. They are widely used as first-line treatment in hemophagocytic lymphohistiocytosis (HLH). Here we describe a newborn who developed t-AML after HLH treatment. We provide detailed clinical, cytogenetic, and molecular characteristics of this patient, including the identification of a novel gene fusion - KMT2A-SNX9 - in t-AML. Considering the dismal outcome of this case, we discuss the side-effects of etoposide administration during HLH treatment in infants.

Elevated IgA and IL-10 levels in very-early-onset inflammatory bowel disease secondary to IL-10 receptor deficiency

OBJECTIVE

To report two patients with very-early-onset inflammatory bowel disease (VEOIBD) secondary to interleukin-10 receptor (IL-10R) mutations, explore immunophenotyping data and plasma cytokine profile on these cases compared to healthy controls, and describe the phenotype of IL-10/IL-10R mutations based on a literature review.

CASE DESCRIPTION

We report on two female infants referred to our tertiary center at the age of ten months, with severe colonic and perianal disease, as well as significant malnutrition, who had shown limited response to usual inflammatory bowel disease (IBD) therapy agents. In the first case, whole-exome sequencing (WES) revealed a homozygous (c.537G>A/p.T179T) mutation in exon 4 of the IL-10RA gene, while in the second patient, compound heterozygosity was identified, also in the IL-10RA gene (chr11:117.859.199 variant A>G/p.Tyr57Cys and chr11: 117.860.335 variant G>T/p.Val123Leu). Both patients underwent hematopoietic cell transplantation (HCT). Immunological work-up of these patients revealed increased IL-10 plasma levels and increased IgA.

COMMENTS

Our case reports disclose novel findings on plasma cytokine profile in IL-10R deficiency, and we describe the severe phenotype of IL-10/IL-10R deficiency that should be recognized by physicians.

Immunomodulation of allergic response in children and adolescents: What we can learn from lymphatic filarial infection

BACKGROUND

Although it is well known that allergic diseases involve a strong Th2 immune response, with production of high levels of specific IgE allergen, knowledge on the association between filarial infection and allergies, among paediatric patients is scarce.

OBJECTIVE

To evaluate the allergic response patterns in cases of filarial infection by comparing peripheral eosinophils, total IgE levels, immediate hypersensitivity and cytokine levels in children and adolescents in Brazil.

METHODS

This was an exploratory study with three groups: (I) with filarial infection and without allergic diseases; (II) without filarial infection and with allergic diseases; and (III) without filarial infection and without allergic diseases. The prick test and specific IgE tests for aeroallergens were performed using five antigens. Peripheral eosinophils and total IgE were also evaluated. IL-4 and IL-5 were determined using whole-blood culture stimulated by three antigens.

RESULTS

Eosinophilia and elevated levels of total IgE (≥400IU/dl) were observed in all groups. The prick test was positive in 56.6% of the cases. Group I presented hypersensitive responses similar to the allergic disease groups. In the whole-blood culture stimulated by Dermatophagoides pteronyssinus, average IL-4 production did not differ significantly among the groups, but IL5 production resulting from stimulation was greater in the allergic disease groups (p<0.05).

CONCLUSIONS

The allergic response pattern in group with filarial infection was similar to that of the groups with and without allergic diseases, but the response to IL-5 in the culture stimulated by D. pteronyssinus was an exclusive characteristic of the allergic group.

Severe combined immunodeficiency in Brazil: management, prognosis, and BCG-associated complications

BACKGROUND

Severe combined immunodeficiency (SCID) is one of the most severe forms of primary immunodeficiency. The objectives of this study were to analyze the diagnosis, treatment, and prognosis of SCID in Brazil and to document the impact of BCG vaccine.

METHODS

We actively searched for cases by contacting all Brazilian referral centers.

RESULTS

We contacted 23 centers and 70 patients from 65 families. Patients were born between 1996 and 2011, and 49 (70%) were male. More than half (39) of the diagnoses were made after 2006. Mean age at diagnosis declined from 9.7 to 6.1 months (P = .058) before and after 2000, respectively, and mean delay in diagnosis decreased from 7.9 to 4.2 months (P = .009). Most patients (60/70) were vaccinated with BCG before the diagnosis, 39 of 60 (65%) had complications related to BCG vaccine, and the complication was disseminated in 29 of 39 (74.3%). Less than half of the patients (30, 42.9%) underwent hematopoietic stem cell transplantation (HSCT). Half of the patients died (35, 50%), and 23 of these patients had not undergone HSCT. Disseminated BCG was the cause of death, either alone or in association with other causes, in 9 of 31 cases (29%, no data for 4 cases).

CONCLUSIONS

In Brazil, diagnosis of SCID has improved over the last decade, both in terms of the number of cases and age at diagnosis, although a much higher number of cases had been expected. Mortality is higher than in developed countries. Complications of BCG vaccine are an important warning sign for the presence of SCID and account for significant morbidity during disease progression.