Calcemia and Inflammatory Markers in Early-Onset Neonatal Infection.

INTRODUCTION: Ionised hypocalcemia (S-Ca2+) has been repeatedly observed in neonates with sepsis. Our aim was to evaluate total calcemia (S-Ca) and its relationship to laboratory markers of infection. METHODS: We retrospectively evaluated total calcemia (S-Ca) and its relationship to laboratory markers of sepsis/infection (serum levels of C-reactive protein - S-CRP and procalcitonin - S-PCT) in 29 full-term neonates with early-onset neonatal infection hospitalized at our neonatology ward between 2012 and 2016. The control group consisted of 705 neonates without infection. RESULTS: In neonates with early-onset infection , the S-Ca on day 1, 2 and 3 was significantly lower (p < 0.0001; p < 0.0001; p = 0.05 versus controls) same as the pooled S-Ca (p < 0.0001 versus controls). There was a weak negative correlation between pooled S-Ca and S-PCT, or pooled S-Ca and S-CRP (r = -0.22, p = 0.06; r = -0.19, p = 0.09). CONCLUSION: S-Ca was decreased in neonates with early-onset infection and did show a slight tendency to inverse correlation with S-CRP and S-PCT. Pediatricians must be aware of the fact that a drop in total S-Ca should alert their attention to the risk of neonatal infection, and, likewise, that the children with neonatal infection are at a higher risk of hypocalcemia with all its consequences.

Three cases of transient neonatal pseudohypoparathyroidism.

Neonatal hypocalcemia is defined as serum calcium (S-Ca) < 2.0 mmol/l in full-term newborns and <1.75 mmol/l in preterm newborns. Neonatal hypocalcemia is either early onset (<3 days of age) or late onset (>3 days of age). Newborns with hypocalcemia are often asymptomatic but may present with hypotonia, apnea, poor feeding, jitteriness, seizures, and cardiac failure. Signs of hypocalcemia rarely occur unless S-Ca drops below 1.75 mmol/l. Neonatal hypocalcemia can be a result of hypoparathyroidism (transient or primary), increased serum calcitonin, sepsis, asphyxia, hepatopathy, hypomagnesemia, high phosphate load, transient hypoparathyroidism, and, rarely, transient neonatal pseudohypoparathyroidism [transient resistance to biological actions of parathyroid hormone (PTH)]. We present the case of three boys (two with gestational age 39 weeks, one 36 weeks; none of them with either asphyxia or sepsis) with mild hypotonia, where S-Ca in the range of 1.67-1.9 mmol/l was detected within the first 3 days of life, together with hyperphosphatemia [serum phosphate (P) 2.5-2.6 mmol/l], normomagnesemia [serum magnesium (S-Mg) 0.77-0.88 mmol/l], normal alkaline phosphatase (ALP) activity (2.8-4.5 µkat/l), and high serum PTH (40-51 pg/ml; normal = 5-28). In spite of the gradual increase of S-Ca, the elevated serum PTH persisted beyond days 3, 4, and 6 in all three boys, together with normal or low-to-normal S-Ca, high or normal-to-high serum P, and no increases in serum ALP. The mothers S-Ca, P, Mg, ALP, and PTH levels were within normal reference ranges. With regard to laboratory results, the diagnosis of transient neonatal pseudohypoparathyroidism (due to immaturity of PTH-receptors) is highly probable in these three neonates.