Multiomic Profiling of Iron Deficient Infant Monkeys Detects Biochemical Signatures of Inflammatory and Neural Dysfunction in Blood and CSF Prior to Anemia

Background: Pre-anemic iron deficiency (ID) and ID anemia in infancy is associated with long-term effects on brain development. Iron is an essential micronutrient needed for multiple neurodevelopmental processes, including energy production, myelination and neurotransmission. Serum and cerebrospinal fluid (CSF) metabolomic and proteomic analyses can potentially characterize the metabolic and protein signatures of aberrant iron-dependent brain development pathways. A better understanding of the timing and course of the biochemical signatures of ID-induced dysfunction in the heme and intrathecal compartments may help with early diagnosis and treatment of iron deficiency prior to onset of anemia.

Objective: To determine proteomic and metabolomic signatures of ID-induced dysfunction in serum and CSF of infant monkeys prior to the onset of iron deficiency anemia (IDA).

Methods: Hematological parameters were determined in rhesus monkey infants (Macaca mulatta) at 4 and 6 months of age as they progressed from preanemic ID to IDA (ID group; n=6) or remained iron-sufficient(IS group; n=12). Blood and CSF were collected at 4 and 6 months and metabolically profiled using HPLC/MS with isobaric standards for identification and quantification. Proteomic quantification utilized a custom TMT-labeled workflow with an Orbitrap Fusion Tribrid mass spectrometer. Serum and CSF metabolomic and proteomic profiles of the ID and IS groups were compared, along with a a third group of infants that became IDA earlier at 4 months of age (IDA group; n=3).

Results: Evidence of pre-anemic ID was apparent in some infant at 4 months of age with clinical IDA evident at 6 months A (Hgb <10 g/dL and MCV <60 fL). A total of 1,128 CSF proteins and 251 serum proteins were identified and quantified. Over 4,000 metabolite features were observed in serum and CSF across three modalities including reverse phase positive, reverse phase negative and HILIC mode. Pathway analyses provided evidence of increased inflammatory activity, impacts on neural pathways, and bioindicators of acute phase responses in ID and IDA groups. Signs of these metabolic changes were already present in the preanemic ID? period (4 months).

Conclusions: Biomarkers indicating indicative of increased inflammatory activity with downstream effects on pathways involved in normal neural function were detectable in both the CSF and serum of ID monkeys prior to the onset of clinical anemia. Brain-specific proteomic and metabolomic profiling of novel analytes in circulation can facilitate earlier diagnosis and treatment of infantile ID to reduce neurodevelopmental risk.

Funded by NIH/NICHD Grant HD089989, this abstract is sponsored by ASH member Zohar Sachs MD, PhD