Pallor and anaemia in infants: the number this graph quotes does not exist for babies
also called pallor infant ALL · anaemia at diagnosis infant · haemoglobin at diagnosis infant leukaemia · pale baby leukaemia
The graph says pallor appears in 54% of children with leukaemia, a figure pooled from patients up to age 18. A search of PubMed for a haemoglobin or platelet count at diagnosis in infant acute lymphoblastic leukaemia returns zero records, so there is no infant-specific number to put in its place.
The same thing, for a scientist
Pallor (54%) and fatigue (46%) are the third and seventh commonest presenting features in Clarke et al.'s pooled 0-18 meta-analysis [E1]. No infant-restricted equivalent was found. A title-checked PubMed search for haemoglobin or platelet count at diagnosis in infant ALL returned 0 records; a search for pallor or fatigue with infant and leukaemia and a frequency term returned 2 records, neither of which reports a frequency (one is a twin case report, one is an adult-survivor fatigue study) [E2]. Infant cohorts report white cell count, KMT2A status, age and CNS status, because those are stratification variables, and do not report the red cell and platelet indices. This is a **bounded absence**: the frequency of anaemia at presentation in infant ALL has, as far as this search can establish, never been published. It is not a negative result - it is an absence of measurement, and the two behave completely differently when reasoning from them.
The searches, so they can be re-run
Run against PubMed via NCBI E-utilities on 2026-09-19 2. Bare-token form used throughout to avoid the parenthesis-parsing failure that returns 0 records for karyotype strings.
| Query | Records | Verdict |
|---|---|---|
(haemoglobin[tiab] OR hemoglobin[tiab] OR platelet[tiab]) AND diagnosis[tiab] AND (infant[ti] OR infants[ti]) AND (acute lymphoblastic leukemia[ti] OR acute lymphoblastic leukaemia[ti]) | 0 | true absence |
(pallor[tiab] OR fatigue[tiab]) AND (infant[tiab] OR infants[tiab]) AND (leukemia[tiab] OR leukaemia[tiab]) AND (frequency[tiab] OR proportion[tiab] OR percent[tiab]) | 2 | both off-target on title check: a monozygotic-twin case report and an adult childhood-cancer-survivor fatigue study |
(infant[ti] OR infants[ti] OR infantile[ti]) AND (leukemia[ti] OR leukaemia[ti]) AND (presenting sign*[tiab] OR presenting symptom*[tiab] OR clinical presentation[tiab]) | 17 | 14 case reports or single-organ presentations; no cohort reporting sign frequencies in infants |
Both British and American spellings were included, and both singular and plural of the multi-word terms, because a [tiab] phrase is matched unstemmed.
Why infant trials do not record this1 deeper
Infant protocols stratify on KMT2A status, age, white cell count, prednisone response and minimal residual disease 34. Haemoglobin and platelet count at presentation are not stratification variables in any infant protocol this beat examined, so they are collected in the case-report form and never tabulated in the publication. The consequence is structural rather than accidental: the presenting features that matter to the family and to the first doctor are exactly the ones the trial literature does not report, because the trial literature exists to allocate treatment, not to describe arrival.
The one adjacent figure, and why it does not fill the gap
The graph's existing pallor entry cites an anaemia frequency of 35.7% from published congenital leukaemia cases. That is a different population (first month of life, myeloid-weighted) and a different denominator (published case reports, which select for the unusual). It bounds the question but does not answer it. A 2026 neonatal case describes severe anaemia and thrombocytopenia at presentation alongside a leucocyte count of 615,400/microlitre 5, which is a single observation, not a frequency.
What would close the gap
Interfant-99, Interfant-06 and MLL-10 have the haemoglobin and platelet values in their case-report forms. A single supplementary table from any one of those trials would give the first infant-specific estimate of anaemia and thrombocytopenia at presentation, with an interval, on several hundred patients. Until then the honest statement in a clinic is that a pale, floppy infant who feeds poorly is a presentation of infant leukaemia whose frequency nobody has measured.
| metric | bounded absence |
|---|---|
| population | infants <1 year with ALL |
| question | frequency of pallor, anaemia and thrombocytopenia at presentation |
| date run | 2026-09-19 |
| source | NCBI E-utilities esearch |
queries run — the numbers behind the chart
[
{
"query": "(haemoglobin[tiab] OR hemoglobin[tiab] OR platelet[tiab]) AND diagnosis[tiab] AND (infant[ti] OR infants[ti]) AND (acute lymphoblastic leukemia[ti] OR acute lymphoblastic leukaemia[ti])",
"records": 0
},
{
"query": "(pallor[tiab] OR fatigue[tiab]) AND (infant[tiab] OR infants[tiab]) AND (leukemia[tiab] OR leukaemia[tiab]) AND (frequency[tiab] OR proportion[tiab] OR percent[tiab])",
"records": 2,
"on_target_after_title_check": 0
},
{
"query": "(infant[ti] OR infants[ti] OR infantile[ti]) AND (leukemia[ti] OR leukaemia[ti]) AND (presenting sign*[tiab] OR presenting symptom*[tiab] OR clinical presentation[tiab])",
"records": 17,
"on_target_after_title_check": 0
}
]- Will the Interfant or JPLSG groups release presenting haemoglobin and platelet distributions from their existing case-report forms? This is a table, not a study.
- Does presenting haemoglobin carry independent prognostic information in infants, as it does not in older children? Nobody has tested it.
- Is there a non-English-language infant cohort that reports these indices and is invisible to an English-language abstract query?
- E1established confidence 5 of 5: Multiple independent lines of evidence; treated as settled in the field.review
Pallor was present in 54% and fatigue in 46% of children in a meta-analysis of 33 leukaemia cohorts aged 0-18 (n = 3084); 6% were asymptomatic at diagnosis.
Clinical presentation of childhood leukaemia: a systematic review and meta-analysis. · Clarke RT, Van den Bruel A, Bankhead C, Mitchell CD, Phillips B, Thompson MJ · Arch Dis Child 2016What this evidence cannot show
Ages 0-18 pooled with no infant stratum. Fatigue in particular is a reported symptom, and the proportion of the 3084 who could report anything is not stated. Cohort studies without control groups, so these are frequencies among cases.
Evidence that argues against this (1)
- Fatigue cannot be elicited from a pre-verbal infant at all, so the 46% figure has no operational meaning in this age group regardless of how well it is estimated in older children. Brown P et al. 2019
- E2moderate confidence 3 of 5: One strong study, or several smaller consistent ones.database
A PubMed search for a haemoglobin or platelet count at diagnosis in infant acute lymphoblastic leukaemia returns zero records, and adjacent searches return only case reports and off-topic hits on title check.
NCBI E-utilities esearch against PubMed: recorded queries and record counts, run 2026-09-19 · Q7-clinical-infant beat (this graph) · NCBI E-utilities 2026What this evidence cannot show
A counted absence is only as good as its symbol set. These queries use current terms plus both spellings; they do not cover the retired symbol MLL in the title field, non-English titles that index without an English abstract, or papers that report the value only in a table without naming it in the title or abstract, which is the likeliest place such a number hides. Absence of a retrievable report is therefore weaker than absence of the measurement.
Evidence that argues against this (1)
- The figures almost certainly exist in the Interfant and MLL-10 case-report forms and could be in a paywalled supplementary table that no abstract-level query can reach; this claim is about retrievability, not about whether anyone ever wrote the number down. Stutterheim J et al. 2025
- E3established confidence 5 of 5: Multiple independent lines of evidence; treated as settled in the field.paper
Interfant-06 stratified infants on KMT2A status, age and white cell count or prednisone response, and found KMT2A rearrangement, age, WBC and prednisone response to be the prognostic factors.
Outcome of Infants Younger Than 1 Year With Acute Lymphoblastic Leukemia Treated With the Interfant-06 Protocol: Results From an International Phase III Randomized Study. · Pieters R, De Lorenzo P, Ancliffe P, Aversa LA, Brethon B, Biondi A, et al. · J Clin Oncol 2019What this evidence cannot show
Abstract only; full text paywalled. The absence of haemoglobin from the model is not evidence that haemoglobin carries no information - nobody tested it.
Evidence that argues against this (1)
- An absence of testing is not a negative result; no infant trial has reported a model including presenting haemoglobin, so its prognostic value is unknown rather than null. Tomizawa D et al. 2020
- E4established confidence 5 of 5: Multiple independent lines of evidence; treated as settled in the field.paper
JPLSG MLL-10 stratified 90 infants into three risk groups by KMT2A status, age and presence of CNS leukaemia, and found minimal residual disease at the end of early consolidation and female sex to be the significant prognostic factors.
A risk-stratified therapy for infants with acute lymphoblastic leukemia: a report from the JPLSG MLL-10 trial. · Tomizawa D, Miyamura T, Imamura T, Watanabe T, Moriya Saito A, Ogawa A, et al. · Blood 2020What this evidence cannot show
n = 90 with 56 in the high-risk group, so the low- and intermediate-risk estimates rest on 15 and 19 patients respectively and their confidence intervals are wide. Abstract read; full text paywalled. Blood counts other than WBC are not in the stratification.
Evidence that argues against this (1)
- Female sex emerging as a prognostic factor in a 90-patient trial with three strata is the kind of finding that does not replicate; it has not been reproduced in Interfant-06. Pieters R et al. 2019
- E5weak confidence 2 of 5: Preliminary, small, indirect, or not yet peer reviewed.paper
A 7-day-old neonate with mixed phenotype acute leukaemia presented with a peak leucocyte count of 615,400/microlitre together with severe anaemia and thrombocytopenia.
Extreme hyperleukocytosis and blueberry muffin skin lesions as the initial presentation of neonatal leukemia: a case report. · Bustamante-Ordonez MA, Macavilca-Toribio MA, Arenas-Vasquez JR, Roman-Lazarte V, Zavaleta-Corvera C, Samanez-Obeso A · BMC Pediatr 2026What this evidence cannot show
A single case report, so it establishes that the combination occurs and nothing about its frequency. Molecular testing for KMT2A rearrangement was negative, so this is not KMT2A-rearranged disease. Cited here only as a bound on severity, with no narrative about the child.
Evidence that argues against this (1)
- Case reports are selected for extremity, so this observation biases upward any impression of how anaemic infants are at presentation. Clarke RT et al. 2016
no infant-specific pallor or anaemia frequency exists; the 54% is an age 0-18 pooled figure
bounded absence in the presenting-feature description of infant ALL
query A1 returns 0 records