NEF PED - Comunicações e Conferências
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- Influenza B-Associated Atypical Hemolytic Uremic SyndromePublication . Mano, L; Rocha, S; Maio, P; Francisco, T; Pereira, G; Gomes, S; Santos, R; Serrão, AP; Abranches, MIntroduction: Influenza A infections have been described to cause secondary hemolytic uremic syndrome and to trigger atypical hemolytic uremic syndrome (aHUS) in individuals with an underlying genetic complement dysregulation. To date, Influenza B has only been reported to trigger aHUS in 2 patients. In 61% of aHUS cases, mutations are found in H, B and I factors, membrane cofactor protein (MCP), C3 and thrombomodulin. MCP (CD46) mutations account for 10-15% of cases. Clinical Case: A 13-year-old boy was transferred to a terciary pediatric centre with acute renal lesion in the context of HUS. Evidence was found for Influenza B infection and results for other etiologic agents were negative. He was treated with Oseltamivir for 5 days. Etiologic study revealed decreased C ́3 (0,81 g/L), normal C ́4 (0,27 g/L) and all antibodies were negative: anti-Beta2 GP1 IgG / IgM, anti-cardiolipine IgG / IgM, anti-neutrophil-citoplasm-PR3 and MPO. Alternate complement pathway study (AH 50) were 112 % of normal value (reference value >70%) and ADAMTS 13 activity were 0.79 (values above 0.67 may be found in aSHU as well as other microangiopathic trombopathies). Molecular study of complement including 11 genes (CFH, CD46 (MCP), CFI, C3, THBD, CFB,CFHR5, CFHR1 CFHR3, CFHR4, DGKE) found a pathogenic heterozygotic missense variant on CD46 (MCP) gene, c.554A>G, p.Asp185Gly, associated with aHUS. Conclusions: aHUS patients should be screened for all known disease-associated genes. Screening should not be stopped after finding a mutation to avoid missing other genetic susceptibility factors influencing disease phenotype, particularly in patients with MCP or CFI mutations, because they have a higher probability of also carrying mutation in another gene than patients with CFHor C3 mutations. Influenza B is a trigger for aHUS and might be underreported as such. Influenza vaccination may protect patients at risk.
- Hypophosphatemic Rickets: A New MutationPublication . Maio, P; Rocha, S; Mano, L; Francisco, T; Sousa, H; Freixo, J; Abranches, MIntroduction: Phosphopenic rickets is characterized by hypophosphatemia with hyperphosphaturia, normal calcemia and normal or mildly elevated PTH. This pathology may be caused by mutations in PHEX gene (phosphate regulating endopeptidase homolog X-linked). We present a clinical report of a girl with phosphopenic rickets, as consequence of a new mutation of PHEX gene. Clinical Case: We present a 4-year-old female, with unremarkable family history, who presented with failure to thrive since the first year of life (height at the 5th centile, and with the age of four below 5th centile). Blood tests showed hypophosphatemia (2.4 mg/dL), elevated alkaline phosphatase (495 U/L), normal calcemia, mildly elevated PTH (97.2 pg/mL; RR <68.3) and normal levels of 25(OH)D and 1.25(OH)D vitamins. The radiological study showed bone deformity of the radius and femur. Diagnosis of hypophosphatemic rickets was made and she was medicated with phosphorus and calcitriol. Currently, the patient has no clinical or radiographic signs of rickets, osseous age is according to real age and there was a considerable increase in growth rate (between 25th and 50th centiles). Renal ultrasound shows incipient signs of nephrocalcinosis since she was 9-year-old. The genetic study detected a heterozigous mutation of the PHEX gene: variant c.767_768del (p.Thr256Serfs*7). This variant is not described in the literature or databases. However, since it introduces a premature stop codon that can produce a truncated protein, this is very likely a pathogenic variant. The parent’s genetic study is still in progress. Conclusions: Presently more than 200 mutations in the PHEX gene have been found to cause hypophosphatemic rickets. We describe a new mutation of this gene. Knowledge about new mutations can improve patient’s outcome.
- Fanconi Syndrome after Ifosfamide ExposurePublication . Madeira Gomes, S; Francisco, T; Serrão, AP; Abranches, Mntroduction: Ifosfamide is an antineoplastic drug frequently used in the treatment of pediatric malignancies. However it is responsible for nephrotoxicity in up to 30% of patients, which can be manifested from asymptomatic tubulopathy to overt renal failure. We report a case of a patient who developed Fancony syndrome after exposure to ifosfamide. Clinical Case: A two-year-old caucasian boy was diagnosed with stage IV Burkitt lymphoma with hepatic and renal involvement without central nervous system (CNS) invasion. Baseline evaluation showed GFR of 60 mL/min per 1.73 m2 (Shwartz formula, k=0.143). He underwent five cycles of chemotherapy involving cyclophosphamide, vincristine, prednisolone, doxorubicin, methotrexate and cytarabine. The patient was in remission but three months later relapsed with evidence of involvement of the liver and kidneys on CT. Another course of chemotherapy was initiated with ifosfamide, carboplatin, etoposide, rituximab (R-ICE) and intratecal administration of methotrexate and aracitabine. After five cycles of R-ICE, the patient had a bone marrow transplant. According to protocol, busulfan, cyclophosphamide, tacrolimus, methotrexate, fluconazole and acyclovir were administered. No immediate complications were registered. Four months after transplant, the patient showed significant downward growth percentile crossing and urinalysis suggested tubulopathy. Upon nephrologist referral, laboratory investigations showed GFR 60 mL/min per 1.73 m2, metabolic acidosis, hypouricemia, hypokalemia, hypophosphatemia, glycosuria, proteinuria, high FEUa and FEK, and low GFR of phosphorus. Fancony syndrome was diagnosed and adequate supplementation was initiated. After literature review the most probable causing agent was ifosfamide. After adequate treatment patient’s general condition improved with slow percentile recovery. Conclusions: Nephrotoxicity secondary to chemotherapy is a major cause of morbidity in pediatric cancer survivors. Our case represents a rare situation with unspecific clinical signs. Clinicians must be alert to the necessity of close monitoring to identify renal toxicity as early as possible and allow adequate supplementation, which is crucial in preventing side effects.