Int J Clin Pediatr

International Journal of Clinical Pediatrics, ISSN 1927-1255 print, 1927-1263 online, Open Access

Article copyright, the authors; Journal compilation copyright, Int J Clin Pediatr and Elmer Press Inc

Journal website http://www.theijcp.org

Case Report

Volume 9, Number 3, September 2020, pages 77-81

Mycoplasma pneumoniae Infection in a 13-Year-Old Girl With Down’s Syndrome During the COVID-19 Pandemic

Figure 1. Chest CT findings in a 13-year-old girl, 7 days after symptoms’ onset. (a) bilateral peripheral patchy ground-glass opacity (red frame), predominant in the left inferior lobe; (b) bilateral hilar lymphadenopathy (pink arrow); (c) pleural effusion (yellow arrow); (d) bronchial wall thickening (blue arrow).

**Table 1.** Laboratory Findings of the Patient
Variables	Reference range	Days after admission	On admission
CK: creatine kinase; RBC: red blood cell count; WBC: white blood cell count; PCO₂: partial pressure of carbon dioxide; PO₂: partial pressure of oxygen; SO₂: oxygen saturation; L. pneumoniae: Legionella pneumoniae; M. pneumoniae: Mycoplasma pneumoniae; S. pneumoniae: Streptococcus pneumoniae; Ag: antigen; IgG: immunoglobin G; IgM: immunoglobin M; PCR: polymerase chain reaction; CMIA: chemiluminescent microparticle immunoassay; IA: immunoassay; COVID-19: coronavirus disease 2019.
C-reactive protein	< 5.0 mg/L		50.8	90.3	55.5
Urea nitrogen	15 - 50 mg/dL	35	37	21	21
Creatinine	0.60 - 1.30 mg/dL	0.65	0.65	0.70	0.78
Sodium	135 - 145 mmol/L	137	139	143	137
Potassium	3.50 - 5.00 mmol/L	4.86	4.51	4.05	3.43
Chloride	97 - 107 mmol/L	100	99	105	101
Carbon dioxide	22.0 - 29.0 mmol/L	27.8	30.4	27.7	23.7
Protein total	60 - 80 g/L	81	74	71	72
Bilirubin total	< 1.2 mg/dL				0.3
CK	20 - 180 U/L				61
Lactate dehydrogenase	< 250 U/L				208
Alanine aminotransferase	13 - 35 U/L				23
Aspartate aminotransferase	7 - 35 U/L				12
Troponin T	< 10				< 5
Hemoglobin	11.0 - 14.5 g/dL	13.5		11.9	12.7
Hematocrit	36-48%	39		33	36
RBC	4.03 - 5.29 × 10⁶/µL	4.35		3.57	4.00
Mean corpuscular volume	76.7 - 89.2 fL	90.6		92.7	91
WBC	4.00 - 10.00 × 10³/µL	7.24		7.68	8.52
Neutrophils	1.50 - 5.90 × 10³/µL	4.94		6.70	7.71
Lymphocytes	1.40 - 3.80 × 10³/µL	1.33		0.38	0.34
Eosinophils	0.04 - 0.76 × 10³/µL	0.27		0.1	0.01
Lymphocytes (%)	20.0-50.0%	18.4		4.9	4
Neutrophils (%)	40.0-70.0%	68.1		87.3	90.5
Platelets	175 - 345 × 10³/µL	360		218	238
Venous blood gases
pH	7.35 - 7.45				7.31
PCO₂	41 - 51 mm Hg				57
PO₂	30 - 40 mm Hg				33
Bicarbonate	22 - 28 mmol/L				28
Base excess	-2.0 - 2.0 mmol/L				0.9
SO₂ (%)	75				49.5
Carboxyhemoglobin	< 2.0 %				0.5
Lactic acid	0.5 - 2.2 mmol/L				3.2
Microbiology
L. pneumoniae Ag (urine)		Negative
M. pneumoniae IgG (CMIA)	< 10 AU/mL	99.6		Negative
M. pneumoniae IgM (CMIA)		Positive		Positive
M. pneumoniae PCR (nasopharynx)				Positive
S. pneumoniae Ag (urine)		Negative
COVID-19 IgG (IA)	< 1.0 AU/mL	Negative
COVID-19 IgM (IA)		Negative
COVID-19 PCR (nasopharynx)			Negative		Negative

Table 1. Laboratory Findings of the Patient

Variables

Reference range

Days after admission

On admission

CK: creatine kinase; RBC: red blood cell count; WBC: white blood cell count; PCO₂: partial pressure of carbon dioxide; PO₂: partial pressure of oxygen; SO₂: oxygen saturation; L. pneumoniae: Legionella pneumoniae; M. pneumoniae: Mycoplasma pneumoniae; S. pneumoniae: Streptococcus pneumoniae; Ag: antigen; IgG: immunoglobin G; IgM: immunoglobin M; PCR: polymerase chain reaction; CMIA: chemiluminescent microparticle immunoassay; IA: immunoassay; COVID-19: coronavirus disease 2019.

C-reactive protein

< 5.0 mg/L

50.8

90.3

55.5

Urea nitrogen

15 - 50 mg/dL

Creatinine

0.60 - 1.30 mg/dL

0.65

0.70

0.78

Sodium

135 - 145 mmol/L

137

139

143

137

Potassium

3.50 - 5.00 mmol/L

4.86

4.51

4.05

3.43

Chloride

97 - 107 mmol/L

100

105

101

Carbon dioxide

22.0 - 29.0 mmol/L

27.8

30.4

27.7

23.7

Protein total

60 - 80 g/L

Bilirubin total

< 1.2 mg/dL

0.3

20 - 180 U/L

Lactate dehydrogenase

< 250 U/L

208

Alanine aminotransferase

13 - 35 U/L

Aspartate aminotransferase

7 - 35 U/L

Troponin T

< 10

< 5

Hemoglobin

11.0 - 14.5 g/dL

13.5

11.9

12.7

Hematocrit

36-48%

RBC

4.03 - 5.29 × 10⁶/µL

4.35

3.57

4.00

Mean corpuscular volume

76.7 - 89.2 fL

90.6

92.7

WBC

4.00 - 10.00 × 10³/µL

7.24

7.68

8.52

Neutrophils

1.50 - 5.90 × 10³/µL

4.94

6.70

7.71

Lymphocytes

1.40 - 3.80 × 10³/µL

1.33

0.38

0.34

Eosinophils

0.04 - 0.76 × 10³/µL

0.27

0.1

0.01

Lymphocytes (%)

20.0-50.0%

18.4

4.9

Neutrophils (%)

40.0-70.0%

68.1

87.3

90.5

Platelets

175 - 345 × 10³/µL

360

218

238

Venous blood gases

7.35 - 7.45

7.31

PCO₂

41 - 51 mm Hg

PO₂

30 - 40 mm Hg

Bicarbonate

22 - 28 mmol/L

Base excess

-2.0 - 2.0 mmol/L

0.9

SO₂ (%)

49.5

Carboxyhemoglobin

< 2.0 %

0.5

Lactic acid

0.5 - 2.2 mmol/L

3.2

Microbiology

L. pneumoniae Ag (urine)

Negative

M. pneumoniae IgG (CMIA)

< 10 AU/mL

99.6

Negative

M. pneumoniae IgM (CMIA)

Positive

M. pneumoniae PCR (nasopharynx)

Positive

S. pneumoniae Ag (urine)

Negative

COVID-19 IgG (IA)

< 1.0 AU/mL

Negative

COVID-19 IgM (IA)

Negative

COVID-19 PCR (nasopharynx)

Negative