BILIRUBIN CRYSTALS IN WHITE CELLS OF NEWBORN WITH HEREDITARY PYROPOIKILOCYTOSIS

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1 BILIRUBIN CRYSTALS IN WHITE CELLS OF NEWBORN WITH HEREDITARY PYROPOIKILOCYTOSIS Alvine Janse van Rensburg, B.Tech Biomedical Technology INTRODUCTION Hereditary pyropoikilocytosis is an inherited (autosomal recessive) red cell membrane disorder which leads to severe haemolytic anaemia. It produces a molecular defect in the membrane protein spectrin and a partial spectrin deficiency. The peripheral blood smear demonstrates bizarre forms, striking anisopoikilocytosis with red cell fragmentation, microspherocytes and budding red cells. The haemolysis can lead to rapid sequestration and destruction of red cells consequently resulting in hyperbilirubinaemia. BACKGROUND Neonatal hyperbilirubinaemia is a commonly encountered clinical entity which need prompt detection and treatment. Jaundice can reach damaging proportions leading to kernicterus. The term kernicterus literally means "yellow kern," with kern indicating the most commonly afflicted region of the brain. In rare cases bilirubin crystals are seen within neutrophils of infants and children with markedly elevated plasma bilirubin. Studies were done to evaluate the clinical significance of the presence of bilirubin crystals and the correlation with serum uncojugated bilirubin. In one study 58.8% of smears from 118 neonates with hyperbilirubinaemia showed the presence of bilirubin crystals within the cytoplasm of neutrophils and in some also within the monocytes, and immature granulocytes. The unconjugated bilirubin with crystal positive smears ranged between µmol/l. The crystal negative smears ranged between µmol/l. The percentage positives in septicaemic neonates were significantly higher compared to other groups (e.g. prematurity, blood group incompatibility, G6PD deficiency and other). Smears made from blood drawn at 30 min intervals reveals the first bilirubin crystals after 90 minutes of in vitro incubation at room temperature.

2 A certain critical concentration of unconjugated bilirubin seems necessary for crystallization to occur, but it could not be determined. BILIRUBIN CRYSTALS The bilirubin crystals are golden or yellow-coloured refractile µm in size and rhomboid, rounded, rectangular to irregular in shape. They are mostly found in neutrophils, but are reported to be seen in the cytoplasm of the immature granulocytes and monocytes. Crystals are only seen in smears from EDTA blood after a minimum incubation of 40 minutes at room temperature. Crystallisation of bilirubin is an in vitro phenomenon and its appearance after 40 minutes or more incubation indicates decreased solubility of unconjugated bilirubin in EDTA-stored blood. Bilirubin crystals in the neutrophils invariably indicate hyperbilirubinaemia due to pathological causes and are associated with a poor prognosis. HEREDITARY PYROPOIKILOCYTOSIS It is a severe form of congenital haemolytic anaemia and is now considered a subtype of homozygous hereditary elliptocytosis.

3 Red cell membrane Hereditary pyropoikilocytosis is the result of a spectrin defect or partial deficiency It is an autosomal recessive disorder meaning two copies of an abnormal gene must be present in order for the disease or trait to develop. The red blood cells show thermal instability and fragmentation at lower temperatures as normal. Red blood cell morphology is similar to that seen in thermal burns. The disorder is more common in African people. Growth retardation, frontal bossing and gallbladder disease can be seen depending on the severity of the anaemia. Laboratory tests will include markers for haemolysis e.g. reticulocyte count, serum bilirubins etc. The mean corpuscular volume (MCV) may be as low as fl. The peripheral blood smear demonstrates severe anisocytosis, fragments, micropoikilocytosis, microspherocytes and budding red cells. Specialized haematology testing show increased osmotic fragility and thermal autohaemolysis. Treatment includes transfusion of packed red cells and other supportive care. Splenectomy may improve anaemia, but has no effect on the morphology of the red cells.

4 CASE STUDY The following results were from a newborn baby with jaundice: Test HB HCT MCV WCC PLT K TBIL UCB Value Range Unit g/dl % fl x10 9 /l x10 9 /l mmol/l µmol/l µmol/l FBC Smear The smear showed severe aniso-poikilocytosis of the red blood cells. A marked left shift of the neutrophils was observed. Crystalline inclusions with orange like opacity were seen identified as bilirubin crystals. The platelet count is most probably inaccurate due to the small red cell forms being counted as platelets. See photos from patient below. Unfortunately the baby passed away within a day.

5 CONCLUSION Several morphological changes in neutrophils give useful clues to underlying disorders. Although bilirubin crystals are very rarely seen, it indicates hyperbilirubinaemia especially unconjugated bilirubin fraction and is associated with a poor prognosis. ACKNOWLEDGMENT I would like to thank to Dr. Lelanie Pretorius for her diagnosis of this case, taking of the photographs and the editing of this article. REFERENCES Case study and photos from Ampath Laboratory Bloemfontein Bain, B.J., Blood cells a practical guide. 4 th ed. Oxford: Blackwell Publishing Ltd Basu, D., Seyiechutuo, S., Nilkund, J Bilirubin crystals in pheripheral blood neutrophils in neonatal bilirubinaemia. British Journal of Haematology Dange P, Desai P, Gupta R, Singh T., Bilirubin crystallization in neutrophils in cases of neonatal unconjugated hyperbilirubinemias. J Appl Hematol 2014;5:117-8

6 Hoffbrand, A.V., Catovsky, D., Tuddenham, E.G.D., Postgraduate Haematology. 5 th ed. Oxford: Blackwell Publishing Ltd Kutlar, A Hereditary Pyropoikilocytosis. Available from Marwaha, N, Sarode, R, Marwaha, RK, Sharma, S, Yachha, S & Narang, A 1990, 'Bilirubin crystals in peripheral blood smears from neonates with unconjugated hyperbilirubinaemia' Medical Laboratory Sciences, vol 47, no. 4, pp Shenoi, U.D., Nandi, G.K.,. Bilirubin Crystals in Neutrophils in Neonatal Hyperbilirubinaemia. Indian J Pediatr, 1997; 64 : 93-96