Decoding Neonatal HLH| Understanding Pathophysiology, Genetic Insights, and Diagnostic Criteria by Dr. K. Senthil Kumar| Kauvery Scientific Journal

Neonatal HLH: Our experience

K. Senthil Kumar*

Senior Consultant Neonatologist, Department Of Neonatology, KMC Hospitals, Trichy, India

Background

Hemophagocytic lymphohistiocytosis belongs to a group of disorders known as histiocytosis characterized by overabundance of tissue macrophages.

Hyperinflammatory syndrome of pathologic immune activation.

Incidence ranges from 1 in 50,000 to 1,50,000.

Associated with a high fatality rate and poor prognosis.

Pathophysiology

Primary HLH/familial HLH – genetic mutation.

Autosomal recessive/X-linked.

7080% present within 1 year of age.

90% asymptomatic in 1st month after birth.

2040% of mutations – FHLH2 loci within perforin gene on chromosome 10q22.1

Secondary HLH

Acquired after strong immunological activation resulting from severe infection, rheumatoid disorders, malignancies, metabolic disorder or prolonged intravenous nutrition.

Infections are known to cause HLHEBV, parvo B19, CMV, bacteria, parasites, and fungi.

Neonatal cases are almost exclusively primary.

Predominant genes associated PRF1, UNC13D

HLH Criteria

Our Data

NO	Age	Clinical features	Examination	Investigations	Antibiotics	HLH criteria	IVIg/steroids	Respiratory support	Complication	Outcome and hospital stay
1.	21 days Baby weight- 2 kg	Fever, abdominal distention, tachypnea	HSM, shock	Bicytopenia, high CRP, thrombocytopenia, coagulopathy, elevated liver enzymes, Ferritin- 82622 IgM scrub positive	Doxycycline	Met	Dexa	HFNC	–	Recovered
2.	18 day Baby weight – 2.3 kg	Fever and fast breathing	HSM	Bicytopenia, elevated CRP, altered LFT Ferritin – 2633 Scrub IgM positive	Doxycycline	Met	Dexa	HFNC	–	Recovered
3.	24 day Baby weight -3.9 kg	Fever , abdominal distention and tachypnea	HSM, shock	Bicytopenia, elevated CRP, coagulopathy, altered LFT, scrub IgM positive Ferritin – 88009	Doxycycline	Met	Dexa	Mechanically ventilated	ARDS, myocardial dysfunction, DIC, hypotensive shock	72 h (declared)
4.	21 day Baby weight – 2.5 kg	Fever, abdominal distention, lethargy	Splenomegaly	Bicytopenia, elevated CRP, altered LFT, coagulopathy, IgM scrub-positive Ferritin – 25635	Doxycycline	Met	IVIG and dexa	Mechanically ventilated	ARDS and DIC, pericardial effusion, seizures	In NICU
5.	24 days Baby weight – 1.9 kg	Fever, lethargy	HSM	Bicytopenia, elevated CRP, coagulopathy, altered LFT, IgM scrub-positive Ferritin 3,08,000	Doxycycline	Met	–	Ventilated	Hypotensive shock, pericardial effusion, LV dysfunction, refractory seizure, DIC	Declared
6.	21 days Baby weight – 2 kg	Fever, lethargy	HSM	Bicytopenia, elevated CRP, altered OT/PT, coagulopathy Ferritin 38105 IgM scrub positive	Doxycycline	Met	IVIG and dexa	Ventilated	MODS, seizure, shock , pericardial and pleural effusion	Recovered x 34 days
7.	28 days Baby weight – 1.9 kg	Reduced activity and refusal of feeds	Splenomegaly	Thrombocytopenia, elevated CRP, deranged coagulation IgM scrub positive Ferritin 3,08,000	Doxycycline	4/8 criteria	Dexa	Yes	Severe coagulopathy, seizures, ARDS	Declared x 36 h

Risk of Mortality

Seizure
ARDS
Shock
Coagulopathy

Corrective Action

Doxycycline + azithromycin
High index of suspicion when worsening
Early aggressive immunosuppression
Seizures early ventilation
Coagulation profile monitoring
Acidosis management
BP monitoring

Dr. K. Senthil Kumar

Neonatologist

NEONATAL HLH: OUR EXPERIENCE

Neonatal HLH: Our experience

K. Senthil Kumar*

Background

Pathophysiology

Secondary HLH

HLH Criteria

Our Data

NO

Age

Clinical features

Examination

Investigations

Antibiotics

HLH criteria

IVIg/steroids

Respiratory support

Complication

Outcome and hospital stay

Risk of Mortality

Corrective Action

Dr. K. Senthil Kumar

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