Severe atypical pneumonia in critically ill patients: a retrospective multicenter study

BACKGROUND

Chlamydophila pneumoniae (CP) and Mycoplasma pneumoniae (MP) patients could require intensive care unit (ICU) admission for acute respiratory failure.

METHODS

Adults admitted between 2000 and 2015 to 20 French ICUs with proven atypical pneumonia were retrospectively described. Patients with MP were compared to Streptococcus pneumoniae (SP) pneumonia patients admitted to ICUs.

RESULTS

A total of 104 patients were included, 71 men and 33 women, with a median age of 56 [44-67] years. MP was the causative agent for 76 (73%) patients and CP for 28 (27%) patients. Co-infection was documented for 18 patients (viruses for 8 [47%] patients). Median number of involved quadrants on chest X-ray was 2 [1-4], with alveolar opacities (n = 61, 75%), interstitial opacities (n = 32, 40%). Extra-pulmonary manifestations were present in 34 (33%) patients. Mechanical ventilation was required for 75 (72%) patients and vasopressors for 41 (39%) patients. ICU length of stay was 16.5 [9.5-30.5] days, and 11 (11%) patients died in the ICU. Compared with SP patients, MP patients had more extensive interstitial pneumonia, fewer pleural effusion, and a lower mortality rate [6 (8%) vs. 17 (22%), p = 0.013]. According MCA analysis, some characteristics at admission could discriminate MP and SP. MP was more often associated with hemolytic anemia, abdominal manifestations, and extensive chest radiograph abnormalities. SP-P was associated with shock, confusion, focal crackles, and focal consolidation.

CONCLUSION

In this descriptive study of atypical bacterial pneumonia requiring ICU admission, mortality was 11%. The comparison with SP pneumonia identified clinical, laboratory, and radiographic features that may suggest MP or CP pneumonia.

Body composition, fasting leptin, and sex steroid administration determine GH sensitivity in peripubertal short children

Serum IGF-I levels in GH-treated subjects demonstrate a wide range of responsiveness to GH. However, the factors influencing GH sensitivity are not well known. The aim of this work was 1) to test whether body composition (determined by dual energy x-ray absorptiometry) or factors related to body composition (fasting blood glucose, FFA, C-peptide, leptin, and insulin sensitivity determined by an insulin tolerance test) influence GH sensitivity; and 2) to study the effect of sex steroid priming on GH sensitivity. We measured serum IGF-I at baseline and 24 h after a single administration of GH (2 mg/m(2)) in 60 healthy prepubertal and early pubertal children (height, -2.1 +/- 1.0 SD score). GH sensitivity, as estimated by the increase in serum IGF-I after GH administration (difference between stimulated and baseline serum IGF-I = delta IGF-I), was also determined after a short-term administration of oral ethinyl E2 in girls and im T in boys. The serum IGF-I concentration was 297 +/- 114 microg/liter at baseline and increased to 429 +/- 160 microg/liter, corresponding to a 46 +/- 29% increase over the baseline value (P < 0.0001, stimulated vs. baseline serum IGF-I). delta IGF-I was not different between gender or pubertal stage. There were positive correlations (P < 0.001) between delta IGF-I and adiposity (total body fat, r = 0.62; trunk fat, r = 0.62), fasting leptin (r = 0.64), and C-peptide (r = 0.54), and a negative correlation with fasting FFA (r = -0.33; P < 0.05) even after adjustment for age, gender, and pubertal stage. These factors remained significant independent predictors of the absolute as well as the percent increase in serum IGF-I in multiple regression analyses. Priming with T and ethinyl E2 had a similar stimulating effect on the serum GH peak in response to the insulin tolerance test. In boys, serum baseline IGF-I increased by 60%, and delta IGF-I was similar after vs. before T administration. By contrast, in girls, serum baseline IGF-I was similar, and delta IGF-I was 60% less after vs. before ethinyl E2 administration. This study indicates that 1) GH sensitivity is determined by fat mass, serum fasting leptin, C-peptide, and FFA; and 2) oral ethinyl E2 and im T have divergent effects on the IGF-I response to a single administration of GH.

Relationships between placental GH concentration and maternal smoking, newborn gender, and maternal leptin: possible implications for birth weight

The control of fetal growth depends on multiple hormones, including both IGF-I and placental GH (PGH) in the mother, and IGF-I rather than pituitary GH (pitGH) in the fetus. Leptin, which is produced by adipocytes and syncitiotrophoblast cells, has also been thought to influence fetal growth by an as yet unknown mechanism. This study assessed the relationships between the GH-IGF-I axis in mothers and newborns, and maternal smoking, neonate gender, and maternal and fetal leptin. We collected blood in 87 mothers at the onset of labor and cord blood immediately after birth in their 87 healthy full-term newborns. GH concentrations were log(10) transformed, and data were expressed as the geometric mean (-1, +1 tolerance factor). PGH was lower in the 30 smoking mothers, as compared with the 57 nonsmoking mothers [18.2 (11.5; 28.6) vs. 27.0 (15.1; 48.2) microg/liter, P < 0.01]. Cord blood IGF-I was lower in neonates from smoking mothers (90 +/- 44 vs. 135 +/- 65 microg/liter, mean +/- SD, P < 0.01), consistent with their lower birth weight percentile (P < 0.01). A gender effect was observed for PGH, which was higher when the newborn was female, and for newborn pitGH and newborn leptin, which were, respectively, lower and higher in females, even after adjustment for birth weight and maternal smoking category (P < 0.05 for all comparisons). Multiple regression analyses identified maternal leptin as a negative predictor of PGH (P < 0.05) and newborn leptin as a positive predictor of newborn IGF-I (P < 0.05). Maternal smoking is associated to decreased maternal PGH and cord blood IGF-I concentrations. A sexual dimorphism for PGH, newborn pitGH, and newborn leptin exists at the time of birth, but its physiological significance remains to be studied. The relationships between maternal leptin and PGH and between cord blood leptin and IGF-I are consistent with the hypothesis that leptin could contribute to the control of fetal growth.

Growth and adult height in GH-treated children with nonacquired GH deficiency and idiopathic short stature: the influence of pituitary magnetic resonance imaging findings

We analyzed the final height of 146 short children with either nonacquired GH deficiency or idiopathic short stature. Our purpose was 1) to assess growth according to the pituitary magnetic resonance imaging findings in the 63 GH-treated children with GH deficiency and 2) to compare the growth of the GH-deficient patients with normal magnetic resonance imaging (n = 48) to that of 32 treated and 51 untreated children with idiopathic short stature (GH peak to provocative tests >10 microg/liter). The mean GH dose was 0.44 IU/kg.wk (0.15 mg/kg.wk), given for a mean duration of 4.6 yr. Among the GH-deficient children, 15 had hypothalamic-pituitary abnormalities (stalk agenesis), all with total GH deficiency (GH peak <5 microg/liter). They were significantly shorter and younger at the time of diagnosis than those with normal magnetic resonance imaging, had better catch-up growth (+2.7 +/- 0.9 vs. +1.3 +/- 0.8 SD score; P < 0.01), and reached greater final height (-1.1 +/- 1.0 vs. -1.7 +/- 1.0 SD score; P < 0.05). Among patients with normal magnetic resonance imaging, there was no difference in catch-up growth and final height between partial and total GH deficiencies. GH-deficient subjects with normal magnetic resonance imaging and treated and untreated patients with idiopathic short stature had comparable auxological characteristics, age at evaluation, and target height. Although they had different catch-up growth (+1.3 +/- 0.8, +0.9 +/- 0.6, and +0.7 +/- 0.9 SD score, respectively; P < 0.01, by ANOVA), these patients reached a similar final height (-1.7 +/- 1.0, -2.1 +/- 0.8, and -2.1 +/- 1.0 SD score, respectively; P = 0.13). Pituitary magnetic resonance imaging findings show the heterogeneity within the group of nonacquired GH deficiency and help to predict the response to GH treatment in these patients. The similarities in growth between the GH-deficient children with normal magnetic resonance imaging and those with idiopathic short stature suggest that the short stature in the former subjects is at least partly due to factors other than GH deficiency.

Macroorchidism due to autonomous hyperfunction of Sertoli cells and G(s)alpha gene mutation: an unusual expression of McCune-Albright syndrome in a prepubertal boy

We report an unusual observation of a 3.8-yr-old boy with McCune-Albright syndrome (MAS) associated with abnormal prepubertal testis enlargement and no sexual precocity. Physical examination showed café-au-lait skin lesions, enlarged testes, prepubertal sized penis, and no pubic or axillary hair. Skeletal radiography disclosed fibrous dysplasia. The serum testosterone level was 0.58 nmol/L and remained below 1.4 nmol/L during the 4-yr follow-up. By contrast, serum inhibin B and anti-Mullerian hormone concentrations were abnormally increased up to 255 pg/mL (childhood range, 35--180) and 792 pmol/L (childhood range, 309--566), respectively. The LH response to a GnRH test was in the prepubertal range, whereas the FSH response was blunted. This abnormal hormone concentration profile indicates autonomous hyperfunction of Sertoli cells, with no evidence of Leydig cell activation. Testicular histology showed tubules with marked Sertoli cell hyperplasia and very rare germinal cells, and interstitial tissue containing mesenchymal cells but no mature Leydig cells. DNA sequence analysis from bone and testis tissues detected the known activating mutation in MAS that results in replacement of Arg by His at codon 201 of the G(s)alpha protein. Other endocrine tests showed excessive GH secretion and moderate adrenal androgen hypersecretion. These findings are consistent with the occurrence of an activating mutation of the G(s)alpha gene mainly expressed in Sertoli cells and weakly expressed or absent in Leydig cells. Abnormal prepubertal testicular enlargement extends the clinical spectrum of MAS, suggesting that determination of serum inhibin B and anti-Mullerian hormone should be considered in boys with this syndrome. This observation demonstrates the usefulness of detailed molecular and biological investigations in atypical cases of MAS.

Failure to kindle seizures after repeated intracerebral administration of arginine vasopressin

In an attempt to kindle seizures with arginine-vasopressin (AVP), we injected AVP into the amygdala or hippocampus of rats. Although behavioral and electrographic alterations were sometimes observed, seizures failed to develop, even in rats that had previously been kindled with electrical stimulation. This and previous failures to kindle seizures by intraventricular injections of AVP call into question the possibility of AVP kindling.