Fanconi Anemia Neuroinflammatory Syndrome (FANS): Brain Lesions and Neurologic Injury in Fanconi Anemia

Fanconi anemia (FA) is a complex inherited bone marrow failure syndrome characterized by chromosomal instability and defective DNA repair causing sensitivity to DNA interstrand cross-linking agents. Our understanding of the full adult phenotype of the disease continues to evolve, as most patients with Fanconi Anemia died of marrow failure in the first decade of life prior to more recent advances in allogeneic hematopoietic cell transplantation. Herein, we report a previously undescribed, clinically concerning, progressive neurologic syndrome in patients with FA. Nine non-immunosuppressed pediatric patients and young adults with FA presented with acute and chronic neurological signs and symptoms associated with distinct neuroradiological findings. Symptoms included, but were not limited to, limb weakness, papilledema, gait abnormalities, headaches, dysphagia, visual changes, and seizures. Brain imaging demonstrated a characteristic radiographic appearance of numerous cerebral and cerebellar lesions with associated calcifications and often a dominant ring enhancing lesion. Tissue from the dominant brain lesions in 4 patients showed non-specific atypical glial proliferation, and a small number of polyomavirus infected microglial cells identified by immunohistochemistry in 2 patients. Numerous interventions were pursued across this cohort, in general with no improvement. Overall, these patients demonstrated significant progressive neurologic decline. This cohort highlights the importance of recognizing Fanconi Anemia Neuroinflammatory Syndrome (FANS), which is distinct from malignancy and warrants careful ongoing evaluation by clinicians.

Optimized vitamin D repletion with oral thin film cholecalciferol in patients undergoing stem cell transplant

Vitamin D deficiency is common in childhood, pervasive before and after bone marrow transplant, and is associated with increased incidence of graft-versus-host disease (GVHD) and decreased survival in patients undergoing hematopoietic stem cell transplant (HSCT). Numerous barriers impede replacement, including malabsorption secondary to gut GVHD, mucositis, inability to take capsules, kidney disease, liver disease, and infection; many patients remain refractory despite vitamin D therapy. We hypothesized that a different formulation of cholecalciferol, administered on the tongue as a readily dissolving oral thin film (OTF), would ease administration and facilitate therapeutic vitamin D levels (>35 ng/mL) in patients who are refractory. In this prospective pilot study, we evaluated 20 patients after HSCT (range, day +21 - day +428 at enrollment) with serum vitamin D levels ≤35 ng/mL. Cholecalciferol OTF strips were administered for 12 weeks. Dosing was based on patient body weight and titrated per individual pharmacokinetics. Wilcoxon matched-pairs signed-rank test demonstrated marked improvement in all 20 patients who were formerly refractory, increasing from a median baseline vitamin D level of 29.2 ng/mL to 58 ng/mL at end of study (P < .0001). All patients demonstrated improvement in serum vitamin D level by week 4 on study, some of whom had been refractory for years prior. Median dose was 1 OTF strip (40 000 IU) per week. No toxicity was observed. This formulation proved to be safe, effective, efficient, and well received. We are eager to explore other patient populations, which might benefit from this promising development, and other therapeutics that might be optimized using this mode of delivery. This trial was registered at www.clinicaltrials.gov as #NCT04818957.

Characteristics of children ≤36 months of age with DIPG: A report from the international DIPG registry

BACKGROUND

Children ≤36 months with diffuse intrinsic pontine glioma (DIPG) have increased long-term survival (LTS, overall survival (OS) ≥24 months). Understanding distinguishing characteristics in this population is critical to improving outcomes.

METHODS

Patients ≤36 months at diagnosis enrolled on the International DIPG Registry (IDIPGR) with central imaging confirmation were included. Presentation, clinical course, imaging, pathology and molecular findings were analyzed.

RESULTS

Among 1183 patients in IDIPGR, 40 were eligible (median age: 29 months). Median OS was 15 months. Twelve patients (30%) were LTS, 3 (7.5%) very long-term survivors ≥5 years. Among 8 untreated patients, median OS was 2 months. Patients enrolled in the registry but excluded from our study by central radiology review or tissue diagnosis had median OS of 7 months. All but 1 LTS received radiation. Among 32 treated patients, 1-, 2-, 3-, and 5-year OS rates were 68.8%, 31.2%, 15.6% and 12.5%, respectively. LTS had longer duration of presenting symptoms (P = .018). No imaging features were predictive of outcome. Tissue and genomic data were available in 18 (45%) and 10 patients, respectively. Among 9 with known H3K27M status, 6 had a mutation.

CONCLUSIONS

Children ≤36 months demonstrated significantly more LTS, with an improved median OS of 15 months; 92% of LTS received radiation. Median OS in untreated children was 2 months, compared to 17 months for treated children. LTS had longer duration of symptoms. Excluded patients demonstrated a lower OS, contradicting the hypothesis that children ≤36 months with DIPG show improved outcomes due to misdiagnosis.

Acquired ornithine transcarbamylase deficiency in pediatric and adolescent patients with fibrolamellar hepatocellular carcinoma

Ornithine transcarbamylase deficiency (OTCD) disrupts the metabolic pathway responsible for converting nitrogenous waste to urea, allowing for excretion. When impaired, ammonia levels accumulate in the blood resulting in severe, sometimes life-threatening toxicities. Abnormalities of the urea cycle are often inherited, though there are some rarer acquired forms. We describe two cases of acquired OTCD in pediatric patients with fibrolamellar hepatocellular carcinoma (FL-HCC). We detail its presentation and management, explore potential underlying pathophysiology, and propose a practice change to optimize care of FL-HCC patients.

Role of the macrophage galactose lectin in the uptake of desialylated LDL

Desialylated low density lipoprotein (LDL) is rapidly taken up and accumulated by both peripheral blood monocytes and cells isolated from human arterial intima consisting predominantly of smooth muscle cells. It is shown that thioglycollate (TG)-elicited mouse macrophages and mouse peritoneal macrophages stimulated with lipopolysaccharide (LPS) show increased expression of a membrane-bound, galactose-specific lectin that could be responsible for this uptake. In LPS-stimulated macrophages accumulation of desialylated LDL is increased ca. 2.6-fold. Accumulation of acetylated LDL in the same cells is reduced, suggesting that the galactose-specific lectin might be responsible for the uptake of desialylated LDL. Transfection of cells with the mouse macrophage Gal/GalNAc-specific lectin (MMGL) increased their capacity to take up asialofetuin (ASF) and, to a smaller extent, desialylated LDL. The uptake of desialylated LDL was small, most likely due to the high k(d) of MMGL for biantennary oligosaccharides as found on LDL, and low concentration of LDL achieved in tissue culture experiments. The data suggest that the expression of galactose-specific lectins can be elevated under inflammatory conditions, and that these receptors could contribute to foam cell formation under conditions of high desialylated LDL concentration, as might be found in arterial intima.

All low density lipoprotein particles are partially desialylated in plasma

Desialylation has been proposed as a natural modification of low density lipoprotein (LDL) increasing atherogenicity. The galactose (Gal)-specific lectin, Ricinus communis agglutinin I (RCA120), has been used to analyse LDL prepared by different methods and it was found that more than 96% of LDL binds to the lectin. The bound LDL could be eluted with Gal or Lactose (Lac), but not with sialic acid, mannose (Man), glucose (Glu) or sodium chloride, indicating that binding occurs via exposed Gal residues on the LDL particle. When freshly isolated whole plasma was loaded on an RCA120 column, apo B-containing lipoproteins (including LDL) were quantitatively bound, whereas other glycosylated serum proteins, like transferrin, were not. Thus desialylation of LDL is not a consequence of its isolation from plasma, or a general property of all serum proteins. Analysis of apolipoprotein B from LDL indicates that only monodesialylated oligosaccharide chains are present, consistent with the rapid clearance of particles having biantennary Gal residues exposed.