J Med Cases

Journal of Medical Cases, ISSN 1923-4155 print, 1923-4163 online, Open Access

Article copyright, the authors; Journal compilation copyright, J Med Cases and Elmer Press Inc

Journal website https://www.journalmc.org

Case Report

Volume 15, Number 9, September 2024, pages 222-226

Hemophagocytic Lymphohistiocytosis Secondary to Acute Human Immunodeficiency Virus and COVID-19

Figure 1. Bone marrow specimen. (a) Bone marrow biopsy showing an increased number of macrophages mixed with normal bone marrow elements. Some of the macrophages have engulfed red cells (arrowhead) in their cytoplasm (H&E stain, × 1,000). (b-d) Bone marrow aspirate smears revealing increased macrophages with increased phagocytic activity - phagocytosed red cells and platelets (arrowhead) and neutrophils (arrow) (Wright-Giemsa stain, × 1,000). The insets show iron-stained smears highlighting iron-laden macrophages with ingested hematopoietic cells (iron stain, × 1,000). H&E: hematoxylin and eosin.

**Table 1.** Laboratory Results
	Patient’s values on admission	Patient’s values at the time of death	Reference values
Prothrombin time (PT), s	13.1	21.7	10.1 - 13.3
International normalized ratio (INR)	1.16	1.84	0.88 - 1.15
Partial thromboplastin time (PTT), s	32	38	26 - 39
Fibrinogen, mg/dL	375	198	232 - 519
Hemoglobin (Hb), g/dL	12.2	6.0	13.0 - 17.0
Hematocrit, %	35.7	19.6	38.0 - 50.0
White blood cell (WBC), × 10³/µL	0.6	2.9	4.0 - 10.6
Platelets (Plt), × 10³/µL	146	101	150 - 400
Red blood cell count (RBC), × 10⁶/µL	4.20	2.05	4.20 - 5.70
Sodium, mmol/L	113	130	134 - 142
Potassium, mmol/L	5.9	6.2	3.3 - 4.9
Chloride, mmol/L	84	96	95 - 110
Bicarbonate, mmol/L	23	7.8	19 - 28
Creatinine, µmol/L	7.79	1.64	0.9 - 1.5
Blood urea nitrogen (BUN), mg/dL	98	42	9 - 23
Total bilirubin, mg/dL	2.2	3.9	0.2 - 1.3
Direct bilirubin, mg/dL	1.8	-	0.0 - 0.3
Aminotransferase (AST), IU/L	2,522	> 6,000	0 - 34
Alanine aminotransferase (ALT), IU/L	787	1,829	10 - 49
Lactate dehydrogenase (LDH), U/L	2,314	> 4,500	120 - 246
Haptoglobin, mg/L	122		40 - 280
D-dimer, mg/L	6,402		≤ 500
Procalcitonin, ng/mL	153.50		0.50
Ferritin, ng/mL	> 16,500	> 16,500	10.5 - 307.3
Lactic acid, mmol/L	1.44

Table 1. Laboratory Results

Patient’s values on admission

Patient’s values at the time of death

Reference values

Prothrombin time (PT), s

13.1

21.7

10.1 - 13.3

International normalized ratio (INR)

1.16

1.84

0.88 - 1.15

Partial thromboplastin time (PTT), s

26 - 39

Fibrinogen, mg/dL

375

198

232 - 519

Hemoglobin (Hb), g/dL

12.2

6.0

13.0 - 17.0

Hematocrit, %

35.7

19.6

38.0 - 50.0

White blood cell (WBC), × 10³/µL

0.6

2.9

4.0 - 10.6

Platelets (Plt), × 10³/µL

146

101

150 - 400

Red blood cell count (RBC), × 10⁶/µL

4.20

2.05

4.20 - 5.70

Sodium, mmol/L

113

130

134 - 142

Potassium, mmol/L

5.9

6.2

3.3 - 4.9

Chloride, mmol/L

95 - 110

Bicarbonate, mmol/L

7.8

19 - 28

Creatinine, µmol/L

7.79

1.64

0.9 - 1.5

Blood urea nitrogen (BUN), mg/dL

9 - 23

Total bilirubin, mg/dL

2.2

3.9

0.2 - 1.3

Direct bilirubin, mg/dL

1.8

0.0 - 0.3

Aminotransferase (AST), IU/L

2,522

> 6,000

0 - 34

Alanine aminotransferase (ALT), IU/L

787

1,829

10 - 49

Lactate dehydrogenase (LDH), U/L

2,314

> 4,500

120 - 246

Haptoglobin, mg/L

122

40 - 280

D-dimer, mg/L

6,402

≤ 500

Procalcitonin, ng/mL

153.50

0.50

Ferritin, ng/mL

> 16,500

10.5 - 307.3

Lactic acid, mmol/L

1.44

**Table 2.** HLH Criteria
HLH-2004 criteria	Present in patient	Reference
HLH: hemophagocytic lymphohistiocytosis.
Fever	No	Peak temperature of > 38.5 °C for > 7 days
Splenomegaly	No	Spleen palpable > 3 cm below costal margin
Cytopenia involving two or more cell lines	Yes (hemoglobin 6.8, platelets 46)	Hemoglobin < 9 g/dL platelets < 100,000/µL
Hypertriglyceridemia or hypofibrinogenemia	Yes (triglycerides 398)	Fasting triglycerides > 177 mg/dL
Hemophagocytosis	Yes (bone marrow confirms)	Biopsy samples of bone marrow, spleen, or lymph nodes
Natural killer cell activity	Not tested	Low or absent
Serum ferritin	Yes (ferritin > 16,500)	> 500 ng/mL
Soluble interleukin-2 (CD25)	Yes (CD25: 10,915)	> 2,400 U/mL or very high for age

Table 2. HLH Criteria

HLH-2004 criteria

Present in patient

Reference

HLH: hemophagocytic lymphohistiocytosis.

Fever

Peak temperature of > 38.5 °C for > 7 days

Splenomegaly

Spleen palpable > 3 cm below costal margin

Cytopenia involving two or more cell lines

Yes (hemoglobin 6.8, platelets 46)

Hemoglobin < 9 g/dL platelets < 100,000/µL

Hypertriglyceridemia or hypofibrinogenemia

Yes (triglycerides 398)

Fasting triglycerides > 177 mg/dL

Hemophagocytosis

Yes (bone marrow confirms)

Biopsy samples of bone marrow, spleen, or lymph nodes

Natural killer cell activity

Not tested

Low or absent

Serum ferritin

Yes (ferritin > 16,500)

> 500 ng/mL

Soluble interleukin-2 (CD25)

Yes (CD25: 10,915)

> 2,400 U/mL or very high for age