Early indicators of neonatal‐onset hereditary thrombotic thrombocytopenia purpura

Abstract

Background Neonatal‐onset hereditary thrombotic thrombocytopenia purpura (hTTP) is often misdiagnosed due to its rarity. It begins with jaundice, similar to infants with ABO incompatibility. Objective To explore early indicators of neonatal‐onset hTTP. Methods This study was a retrospective case series of newborns with hTTP and ABO incompatibility. We compared the clinical characteristics and laboratory test results in these two groups. Results This study included four hTTP patients and 20 ABO‐incompatible newborns. All patients manifested disease during the neonatal period. There were equal numbers of males and females in each group. hTTP newborns showed earlier (median difference, 57.0 h; 95% confidence interval [CI], 24.0–65.0) and more severe hyperbilirubinemia (mean difference, 8.0 mg/dl; 95% CI, 3.8–12.1) than ABO‐incompatible newborns. In hTTP newborns, anemia was more common within 7 days after birth than in ABO‐incompatible newborns (odds ratio, 25.4; 95% CI, 1.2–551.6), and platelet counts were lower than in ABO‐incompatible newborns (17 ± 12 × 10 9 /L vs. 291 ± 76 × 10 9 /L). The levels of serum creatinine (median difference, 51.8 μmol/L; 95% CI, 16.0–109.4) and blood urea nitrogen (median difference, 5.7 mmol/L; 95% CI, 2.8–38.7) were higher in hTTP newborns than in ABO‐incompatible newborns. There were no significant differences in white blood cell counts, C‐reactive protein, alanine aminotransferase, or albumin levels. Conclusions Severe jaundice soon after birth, early anemia, and severe thrombocytopenia were more common in newborns with hTTP than ABO incompatibility. These are distinguishing early features of hTTP.

Hereditary thrombotic thrombocytopenic purpura: The risk for death at birth

“…In this issue of RPTH, Liu and colleagues describe the distinguishing clinical features of infants with hTTP and ABO incompatibility. 10 Their data document the clear differences between these two causes of neonatal hyperbilirubinemia and provide criteria for recognition of hTTP in newborn infants. 1).…”

“…Although hTTP can cause severe hemolysis, hyperbilirubinemia, and thrombocytopenia soon after birth, to the best of my knowledge there have been no published comparisons to distinguish hTTP from ABO alloimmunization until now. In this issue of RPTH , Liu and colleagues describe the distinguishing clinical features of infants with hTTP and ABO incompatibility 10 . Their data document the clear differences between these two causes of neonatal hyperbilirubinemia and provide criteria for recognition of hTTP in newborn infants.…”

“…Suspicion of hTTP is sufficient for initiating treatment; diagnosis of hTTP by documentation of ADAMTS13 deficiency requires several days. Early diagnosis and close follow‐up of infants with hTTP would prevent the recurrences that occurred in the four patients reported by Liu et al 10 …”

“… Note : These data are from tables 1 and 3 and supplemental table 1 of Liu et al's publication. 10 a All 20 patients with ABO incompatibility were treated only with phototherapy and IVIg. All four patients with hTTP were also treated with phototherapy and IVIg.…”

“…Hematologists, even pediatric hematologists, may not become involved in the care of newborn infants with severe thrombocytopenia. Therefore, I ask all hematologists who read the report of Liu et al 10 to share it with their colleagues in neonatal intensive care units. hTTP may not be as rare as we think it is.…”