Avascular necrosis in sickle cell (homozygous S) patients: Predictive clinical and laboratory indices

Background: Pathogenetic mechanism as well as laboratory and clinical correlates of osteonecrosis in sickle cell have not been fully investigated. The aim of this study is to investigate the predictive value of the steady state white cell and platelet count as well as the frequency of bone pain crisis per annum to detect sickle cell patients who will eventually develop avascular necrosis (AVN).Patients and Methods: A 5 year retrospective analysis of 122 homozygous S (HbSS) patients, aged 6‑49 years (mean age 24.7 ± 7 years), out of which 16 patients (13.1%) had developed AVN within the years under review.Results: The prevalence of AVN in sickle cell patients was determined to be 13.1 per 1000. The steady state white cell count, platelet count, frequency of bone pain crisis and hematocrit, was compared in patients that develop AVN and those who had not over the period. Only the steady state platelet count was found to differ significantly (P = 0.011) between these two patient groups and to correlate positively (Pearson correlation coefficient = −0.251) with development of AVN. The hematocrit, white cell count, and frequency of bone pain crisis were found neither to differ significantly nor correlate with the development of AVN.Conclusion: In conclusion, patients with a raised steady state platelet count may have a higher tendency to develop AVN and may require closer orthopedic review and prophylactic intervention.Key words: Avascular necrosis, homozygous S, platelet count, sickle cell anemia, white cell coun

Excess risk of adverse pregnancy outcomes in women with porphyria: a population-based cohort study

The porphyrias comprise a heterogeneous group of rare, primarily hereditary, metabolic diseases caused by a partial deficiency in one of the eight enzymes involved in the heme biosynthesis. Our aim was to assess whether acute or cutaneous porphyria has been associated with excess risks of adverse pregnancy outcomes. A population-based cohort study was designed by record linkage between the Norwegian Porphyria Register, covering 70% of all known porphyria patients in Norway, and the Medical Birth Registry of Norway, based on all births in Norway during 1967–2006. The risks of the adverse pregnancy outcomes preeclampsia, delivery by caesarean section, low birth weight, premature delivery, small for gestational age (SGA), perinatal death, and congenital malformations were compared between porphyric mothers and the rest of the population. The 200 mothers with porphyria had 398 singletons during the study period, whereas the 1,100,391 mothers without porphyria had 2,275,317 singletons. First-time mothers with active acute porphyria had an excess risk of perinatal death [adjusted odds ratio (OR) 4.9, 95% confidence interval (CI) 1.5–16.0], as did mothers with the hereditable form of porphyria cutanea tarda (PCT) (3.0, 1.2–7.7). Sporadic PCT was associated with an excess risk of SGA [adjusted relative risk (RR) 2.0, 1.2–3.4], and for first-time mothers, low birth weight (adjusted OR 3.4, 1.2–10.0) and premature delivery (3.5, 1.2–10.5) in addition. The findings suggest women with porphyria should be monitored closely during pregnancy