Case 2
A 13-year old boy with stage 4 neuroblastoma of right adrenal with multiple nodal, bone and bone marrow metastases underwent chemotherapy (HKPHOSG-NB-07 N7 protocol), gross total tumour resection, autologous cord blood transplantation with VAMP conditioning followed by immunotherapy (5 cycles of dinutuximab with alternating cycles of sargramostim and aldesleukin and inter-cycle isotretinoin). Complete remission was achieved but he had spinal relapse 4.5 years after treatment presented with cord compression at T5-T9 level warranting emergency laminectomy and spinal tumour excision. He then received one cycle of temozolomide and irinotecan followed by adjuvant radiotherapy 30Gy/10Fr to T5-T9 vertebrae and haploidentical transplant with maternal TCRαβ/CD45RA depleted graft. Total lymphoid irradiation 8Gy, fludarabine 150mg/m2, thiotepa 10mg/kg and melphalan 140mg/m2 were employed as conditioning. Neutrophil and platelet engrafted on D+10 and D+11 respectively with 99% donor chimerism in D+30 marrow. Post-transplant course was complicated with severe acute GVHD involving skin (grade 2-3), liver (grade 2, biopsy-proven) and gut (grade 4) requiring prolonged and heavy immunosuppression including prednisolone, cyclosporine, and mycophenolate mofetil. He also suffered from disseminated Nocardia infection complicated with left lower lobe necrotizing pneumonia, parapneumonic effusion, hydropneumothorax and bronchopleural fistula requiring prolonged course of antimicrobials including meropenem, levofloxacin, ceftriaxone, cotrimoxazole, linezolid and amikacin. Due to liver GVHD, patient had grossly deranged liver function with peak ALT 720 IU/L, AST 506 IU/L, GGT 1,916 IU/L at 8 months post-transplant. His worst cholestasis occurred as post-transplant 2 years with total bilirubin 312 μmol/L and direct bilirubin 270 μmol/L (Figure 1C and Table 1) . He was noted to have lipemic blood sample (Figure 1D) at post-transplant 2 years and lipid profile done revealed TC 13.6 mmol/L, LDL-C (calculated) 11.4 mmol/L, HDL-C 0.2 mmol/L, non-HDLC 13.4 mmol/L and TG 4.2 mmol/L (Table 1) . Physical exam did not show any xanthoma. With the clinical context of severe cholestasis, LDL-C was measured directly and it showed discordance between the measured and calculated LDL-C values (measured 1.7 mmol/L versus calculated 11.4 mmol/L). Low ApoA (0.52 g/L) and elevated ApoB (1.7 g/L) levels were revealed. Trace chylomicron band, Lp-X band and faint lipoprotein Y bands were detected in lipoprotein electrophoresis (Figure 1D) . Patient had neuroblastoma relapse and is currently undergoing palliative care.