Post-radiotherapy hyperthyroidism: a rare complication of cancer treatment in the child]

Abnormalities of thyroid function, specially hypothyroidism, are common complications of head and neck irradiation for childhood cancer. Hyperthyroidism is rare and can be misdiagnosed. We report two observations of this condition. OBSERVATIONS: The first patient received conventional craniospinal irradiation for a localized medulloblastoma. Three years later, he presented with profuse sweating, irritability and paroxysmal tachycardia. Biologic evaluation revealed a peripheral hyperthyroidism. The patient was treated with antithyroidian hormonal treatment. The second patient received an irradiation for an undifferentiated nasopharyngeal carcinoma. Three years later, she developed a progressive thyrotoxicosis which was attributed to hyperthyroidism after six months of evolution. Hormonal treatment improved the clinical state after several weeks. CONCLUSION: Hyperthyroidism is a rare complication of head and neck irradiation. This condition justifies a periodic and prolonged evaluation of thyroid function.     

Repeat sequences in block 2 of Plasmodium falciparum merozoite surface protein 1 are targets of antibodies associated with protection from malaria

Human antibodies to the block 2 region of Plasmodium falciparum merozoite surface protein 1 (MSP1) are associated with a reduced prospective risk of clinical malaria. Block 2 is highly polymorphic, but all known alleles can be grouped into three major types. Two of these types (the K1-like and MAD20-like types) contain type-specific sequences (found in all alleles of a particular type) that flank polymorphic tripeptide repeats. These repeats contain both type-specific and subtype-specific sequences. To evaluate the antibody recognition of these parts of block 2, a new panel of six recombinant proteins was used (fused type-specific flanking sequences and two representative repeat sequences for each of the K1-like and MAD20-like types separately). Extensive testing of these antigens and full-length block 2 antigens showed that human serum immunoglobulin G antibodies induced by infection can recognize (i) type-specific epitopes in the repeats, (ii) subtype-specific epitopes in the repeats, or (iii) type-specific epitopes in flanking sequences. A large prospective study in The Gambia showed that antibodies to the repeats are strongly associated with protection from clinical malaria. The results are important for design of a vaccine to induce protective antibodies, and they address hypotheses about repeat sequences in malaria antigens.     

Long term follow up of 69 patients treated for optic pathway tumours before the chemotherapy era

AIM—To analyse the long term results of conservative management with radiotherapy in patients with optic pathway tumours.DESIGN—All 69 patients were symptomatic at diagnosis and most neoplasms involved the optic chiasm and hypothalamus.RESULTS—At 10 years, overall survival and progression free survival were 83% and 65.5%, respectively. After radiotherapy, vision improved in 18 patients and remained stable in 29 other patients. Cerebrovascular complications occurred in nine of 53 patients treated with radiotherapy after a median interval of two and a half years. These complications were five times more frequent in patients with neurofibromatosis type 1 (NF1). Severe intellectual disabilities were present in 18 children, most of whom underwent irradiation at a very young age (median age, 4years).IMPLICATIONS—Radiotherapy is a valuable treatment in terms of tumour response, visual outcome, and progression free survival. However, in young children and in patients with NF1, major sequelae are encountered and new treatment strategies should be proposed for these patients.     

Patterns of neuropsychological deficits in children with medulloblastoma according to craniospatial irradiation doses

This study aimed to analyse the relationship between supratentorial irradiation dose and the intellectual outcome in 36 children (aged between 5 and 15 years) treated for medulloblastoma. The supratentorial radiation dose was reduced to 25 Gy in 23 children and given at the standard dose, 35 Gy, in 13 other children. Neuropsychological evaluation was performed at a mean of 4.3 years (SD 4.7 years) after radiotherapy. The supratentorial radiation dose was the principal risk factor associated with impaired intellectual outcome. Verbal fluency, immediate word list recall, block design, and fine motricity of the dominant hand were significantly lower in children irradiated at the standard doses than in those irradiated at reduced doses. These findings suggest that the dose of radiotherapy applied to the brain strongly influences later verbal and non-verbal skills in children with medulloblastoma. This should be taken into account in treatment planning and in rehabilitation programs.     

Standard-risk medulloblastoma treated by adjuvant chemotherapy followed by reduced-dose craniospinal radiation therapy: a French Society of Pediatric Oncology Study.

OBJECTIVE: The primary objective of this study was to decrease the late effects of prophylactic radiation without reducing survival in standard-risk childhood medulloblastoma. PATIENTS AND METHODS: Inclusion criteria were as follows: children between the ages of 3 and 18 years with total or subtotal tumor resection, no metastasis, and negative postoperative lumbar puncture CSF cytology. Two courses of eight drugs in 1 day followed by two courses of etoposide plus carboplatin (500 and 800 mg/m(2) per course, respectively) were administered after surgery. Radiation therapy had to begin 90 days after surgery. Delivered doses were 55 Gy to the posterior fossa and 25 Gy to the brain and spinal canal. RESULTS: Between November 1991 and June 1998, 136 patients (median age, 8 years; median follow-up, 6.5 years) were included. The overall survival rate and 5-year recurrence-free survival rate were 73.8% +/- 7.6% and 64.8% +/- 8.1%, respectively. Radiologic review showed that 4% of patients were wrongly included. Review of radiotherapy technical files demonstrated a correlation between the presence of a major protocol deviation and treatment failure. The 5-year recurrence-free survival rate of patients included in this study with all optimal quality controls of histology, radiology, and radiotherapy was 71.8% +/- 10.5%. In terms of sequelae, 31% of patients required growth hormone replacement therapy and 25% required special schooling. CONCLUSION: Reduced-dose craniospinal radiation therapy can be proposed in standard-risk medulloblastoma provided staging and radiation therapy are performed under optimal conditions.     

Efficacy of artesunate plus pyrimethamine-sulphadoxine for uncomplicated malaria in Gambian children: a double-blind, randomised, controlled trial

This double-blind, randomized, controlled study investigated the efficacy, safety and tolerability of artesunate plus pyrimethamine-sulphadoxine for uncomplicated malaria among Gambian children. Combined use of artesunate and pyrimethamine-sulphadoxine was hypothesized to delay or prevent resistance, which proved to be effective in reducing childhood mortality in sub-Saharan Africa. A total of 600 children with acute uncomplicated Plasmodium falciparum malaria, 6 months to 10 years old, were randomly administered pyrimethamine-sulphadoxine (25 mg/500 mg) with placebo, 4 mg/kg body weight pyrimethamine-sulphadoxine plus 1 dose of artesunate, or pyrimethamine-sulphadoxine plus 4 mg/kg body weight artesunate for 3 days. Results indicate that combined treatment was well tolerated. On day 1, 178 of 381 children treated with artesunate were still parasitemic compared with 157 of 195 children in the pyrimethamine-sulphadoxine group. On the other hand, failure rates on day 14 were 3.1% in the pyrimethamine-sulphadoxine group and 3.7% in the 1-dose artesunate group and 1.6% in the 3-dose group. Insignificant differences were found among children administered 1-dose and 3-dose artesunate, and were found less likely to be gametocytemic after treatment. In conclusion, this study confirms the safety and efficacy of a combined treatment, which eventually results in lower gametocyte rates and lower transmission rates.     

A multimedia consent tool for research participants in the Gambia: a randomized controlled trial

ObjectiveTo assess the effectiveness of a multimedia informed consent tool for adults participating in a clinical trial in the Gambia.MethodsAdults eligible for inclusion in a malaria treatment trial (n = 311) were randomized to receive information needed for informed consent using either a multimedia tool (intervention arm) or a standard procedure (control arm). A computerized, audio questionnaire was used to assess participants’ comprehension of informed consent. This was done immediately after consent had been obtained (at day 0) and at subsequent follow-up visits (days 7, 14, 21 and 28). The acceptability and ease of use of the multimedia tool were assessed in focus groups.FindingsOn day 0, the median comprehension score in the intervention arm was 64% compared with 40% in the control arm (P = 0.042). The difference remained significant at all follow-up visits. Poorer comprehension was independently associated with female sex (odds ratio, OR: 0.29; 95% confidence interval, CI: 0.12–0.70) and residing in Jahaly rather than Basse province (OR: 0.33; 95% CI: 0.13–0.82). There was no significant independent association with educational level. The risk that a participant’s comprehension score would drop to half of the initial value was lower in the intervention arm (hazard ratio 0.22, 95% CI: 0.16–0.31). Overall, 70% (42/60) of focus group participants from the intervention arm found the multimedia tool clear and easy to understand.ConclusionA multimedia informed consent tool significantly improved comprehension and retention of consent information by research participants with low levels of literacy.     

The impact of childhood vaccines on bacterial carriage in the nasopharynx: a longitudinal study

Background

There is increasing evidence that childhood vaccines have effects that extend beyond their target disease. The objective of this study was to assess the effects of routine childhood vaccines on bacterial carriage in the nasopharynx.

Methods

A cohort of children from rural Gambia was recruited at birth and followed up for one year. Nasopharyngeal swabs were taken immediately after birth, every two weeks for the first six months and then every other month. The presence of bacteria in the nasopharynx (Haemophilus influenzae, Streptococcus pneumoniae, Staphylococcus aureus) was compared before and after the administration of DTP-Hib-HepB and measles-yellow fever vaccines.

Results

A total of 1,779 nasopharyngeal swabs were collected from 136 children for whom vaccination data were available. The prevalence of bacterial carriage was high: 82.2% S. pneumoniae, 30.6%, S.aureus, 27.8% H. influenzae. Carriage of H. influenzae (OR = 0.36; 95% CI: 0.13, 0.99) and S. pneumoniae (OR = 0.25; 95% CI: 0.07, 0.90) were significantly reduced after measles-yellow fever vaccination; while DTP-Hib-HepB had no effect on bacterial carriage.

Conclusions

Nasopharyngeal bacterial carriage is unaffected by DTP-Hib-HepB vaccination and reduced after measles-yellow fever vaccination.     

Mass drug administration with azithromycin for trachoma elimination and the population structure of Streptococcus pneumoniae in the nasopharynx

ObjectiveMass drug administration (MDA) with azithromycin for trachoma elimination reduces nasopharyngeal carriage of Streptococcus pneumoniae in the short term. We evaluated S. pneumoniae carried in the nasopharynx before and after a round of azithromycin MDA to determine whether MDA was associated with changes in pneumococcal population structure and resistance.MethodsWe analysed 514 pneumococcal whole genomes randomly selected from nasopharyngeal samples collected in two Gambian villages that received three annual rounds of MDA for trachoma elimination. The 514 samples represented 293 participants, of which 75% were children aged 0–9 years, isolated during three cross-sectional surveys (CSSs) conducted before the third round of MDA (CSS-1) and at 1 (CSS-2) and 6 (CSS-3) months after MDA. Bayesian Analysis of Population Structure (BAPS) was used to cluster related isolates by capturing variation in the core genome. Serotype and multilocus sequence type were inferred from the genotype. Antimicrobial resistance determinants were identified from assemblies, including known macrolide resistance genes.ResultsTwenty-seven BAPS clusters were assigned. These consisted of 81 sequence types (STs). Two BAPS clusters not observed in CSS-1 (n = 109) or CSS-2 (n = 69), increased in frequency in CSS-3 (n = 126); BAPS20 (8.73%, p 0.016) and BAPS22 (7.14%, p 0.032) but were not associated with antimicrobial resistance. Macrolide resistance within BAPS17 increased after treatment (CSS-1 n = 0/6, CSS-2/3 n = 5/5, p 0.002) and was carried on a mobile transposable element that also conferred resistance to tetracycline.DiscussionLimited changes in pneumococcal population structure were observed after the third round of MDA, suggesting treatment had little effect on the circulating lineages. An increase in macrolide resistance within one BAPS highlights the need for antimicrobial resistance surveillance in treated villages.