Anaemia in pneumonia: A case report

Suresh Chelliah

Department of Pediatrics, Kauvery Hospital, Trichy, India

Background

The pneumococcal vaccine has drastically reduced the incidence of invasive pneumococcal disease in Western countries. In India, the actual disease burden is not known because of the use of antibiotics before blood culture and the lack of utilization of lab services. Pneumococcus affects many systems and we present a case of pneumococcal pneumonia/sepsis with a rare complication.

Case presentation

A 1-year-old girl was admitted with complaints of fever for 5 days that was associated with cough, coryza, vomiting, and poor feeding but there was no history of fast breathing. On examination, she was irritable, febrile, and had scattered crepitations over her left lung. She was treated with oral medications prior to admission.

Investigations revealed leucocytosis and elevated CRP. X-ray chest showed homogenous opacity over the left lower zone. Streptococcus pneumoniae was isolated in blood and antibiotics were continued as per culture-sensitivity pattern.

On day 4 of admission, she was found to be lethargic and edematous. She was pale and had reduced urine output. Hemoglobin was 3 g/dl. Autoimmune hemolytic anemia/sepsis-induced HUS (Hemolytic Uraemic Syndrome) was considered.

One unit of PRBC was transfused. DCT was positive. LDH, reticulocyte count, and creatinine(2.3mg%) were elevated. Liver function test and coagulation profile were normal. USG screening showed acute kidney injury, GB sludge, mild ascites with bilateral pleural effusion with consolidation over the left lower lobe. Peripheral blood smear showed a leucoerythroblastic blood picture with polychromatophilic RBC – schistocytes indicative of hemolysis.

She was treated conservatively and improved well. Repeat hemoglobin – 7.3 g/dl. Urea and creatinine levels decreased well and the child was doing well on follow-up.

Discussion

Sudden pallor in a child may be due to hemolysis or hemorrhage. This child had pallor but no icterus, splenomegaly, or hemoglobinuria. Though DCT was positive, other findings were not suggestive of Autoimmune hemolytic anemia. Drug indued hemolytic anaemia was condered a possibility, but a high Creatinine value was thought to favour HUS, though rare following a non diarrhoeal illness. Serotyping of the bacteria at CMC Vellore revealed Strep pneumoniae Type 3, a vaccine-preventable strain.

HUS following Pneumococcal infection is an uncommon condition and involves 5% of all cases of HUS in children but 38-43% of HUS cases are not caused by STEC (Shiga toxin-producing E. coli). The incidence of HUS following invasive pneumococcal infections is estimated at 0.4-0.6%

There is evidence of a role for the Thomsen-Friedenreich (TF) cryptantigen. This antigen is a component of the surface structure of erythrocytes, platelets, and glomerular endothelial cells and is normally hidden by neuraminic acid. Neuraminidase, produced by pneumococci, cleaves the N-acetyl neuraminic acid from the cell surface and exposes the TF antigen. Pre-formed host IgM antibodies then bind the TF antigen and are postulated to initiate the cascade of events leading to HUS. The activated TF antigen is also present on hepatocytes, and this may explain the occurrence of transient hepatic dysfunction in some patients. The exposed TF antigen results in a variety of antigen-antibody interactions, many of which occur on the plasma membrane of red blood cells. The direct Coombs’ test detects antibodies that coat these surfaces and gives positive results in approximately 90% of cases of pneumococcal HUS.

Conclusion

Invasive pneumococcal disease is mostly vaccine-preventable. Serotyping of isolates at sentinel centers is essential for knowing the pattern prevalence locally. Uncommon presentations should be documented to make sure these are thought of when a similar picture is encountered.

Acknowledgments

The child was managed by Dr N. Venkatesh and was assisted by the Kauvery Paediatric unit. We thank Dr. Thilagavathy and our colleagues at the lab and blood bank who provided vital assistance in the management. Dr Nithya helped draft the manuscript.

Dr. D. Suresh Chelliah

Senior Consultant Paediatrician (Head – Academics)

Anaemia in pneumonia: A case report