Association between elevated prolactin levels and circulating erythroid precursors in dialyzed patients

[Pregnancies in hemodialysis and in patients with end-stage chronic kidney disease : epidemiology, management and prognosis]

Pregnancy in patients presenting end-stage renal disease is rare and there are currently no recommendations for the management of these patients. In hemodialysis patients, reduced fertility and medical reluctance limit the frequency of pregnancies. Although the prognosis has significantly improved, a significant risk for unfavorable maternal (pre-eclampsia, eclampsia) and fetal (pre-term birth, intrauterine growth restriction, still death) outcome still remains. Increasing dialysis dose with the initiation of daily dialysis sessions, early adaptation of medications to limit teratogenicity and management of chronic kidney disease complications (anemia, hypertension) are required. A tight coordination between nephrologists and obstetricians remains the central pillar of the care. In peritoneal dialysis, pregnancy is also possible with modification of the exchange protocol and reducing volumes.

Effects of combination of proliferative agents and erythropoietin on left ventricular remodeling post-myocardial infarction

Erythropoietin (EPO) has the potential to improve ischemic tissue by mobilizing endothelial progenitor cells and enhancing neovascularization. We hypothesized that combining EPO with human chorionic gonadotrophin (hCG) would improve post-myocardial infarction (MI) effects synergistically.

METHODS

After MI, five to seven animals were randomly assigned to each of the following treatments: control; hCG; EPO; hCG + EPO, and prolactin (PRL) + EPO. Follow-up echocardiograms were performed to assess cardiac structure and function. Apoptosis was determined by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay and western blot analysis for apoptosis-related proteins, and cell proliferation by immunostaining for Ki67 and c-kit cells.

RESULTS

The MI-mediated increased chamber systolic dimension (p < 0.05 in controls) was attenuated by hCG, EPO, and hCG + EPO (p < 0.05 vs. control) but not PRL + EPO. Similarly all treatment groups, except PRL + EPO, reduced MI-induced increases (p < 0.05 vs. control) in ejection fraction (EF). The functional improvement in the EPO-treated groups was accompanied by increased capillary density. Apoptosis was markedly reduced in all treated groups. Significantly more cardiac c-kit(+) cells were found in the hCG + EPO group.

CONCLUSION

Our findings revealed that EPO, hCG, or their combination ameliorate cardiac remodeling post-MI. Whereas EPO stimulates neovascularization only and hCG + EPO stimulates c-kit+ cell proliferation. These data suggest that combining mobilizing and proliferative agents adds to the durability and sustainability of cytokine-based therapies for remodeling post-MI.

Panhypopituitarism secondary to a macroprolactinoma manifesting with pancytopenia: case report and literature review

OBJECTIVE

To present a case of pancytopenia associated with hypopituitarism secondary to a macroprolactinoma.

METHODS

We report the clinical features on presentation and results of laboratory investigation. Findings on magnetic resonance imaging are illustrated. The response to hormone replacement therapy is summarized.

RESULTS

A 46-year-old man was referred with pancytopenia and secondary hypothyroidism. Laboratory investigation revealed hypopituitarism and a substantially increased prolactin level. Magnetic resonance imaging of the head demonstrated a macroprolactinoma. Hematologic investigation disclosed no other cause for the pancytopenia. Hormone replacement therapy was initiated with hydrocortisone, levothyroxine, and testosterone. Cabergoline was used to induce regression of the prolactinoma. A rapid improvement was seen in the cytopenias, with normalization of the blood cell counts after 8 months of treatment. This result has been sustained during 29 months of follow-up.

CONCLUSION

Pancytopenia associated with hypopituitarism has been reported in the literature as a rare occurrence limited to isolated case reports, predominantly associated with Sheehan syndrome. To our knowledge, this is the first reported case of pancytopenia associated with a macroprolactinoma. This finding is noteworthy because prolactin alone has been reported to support hematopoiesis in animal studies.

Decreased expression of stem cell factor in esophageal and gastric mucosa after esophagogastric anastomosis for cancer: potential relevance to motility

BACKGROUND

Esophageal replacement with gastric tube is a well-established reconstruction of the alimentary tract after esophagectomy in cancer patients. The resulting molecular events in the transposed gastric tube and residual esophagus have yet to be investigated. Stem cell factor (SCF) was recently shown to be critical for signaling in gastrointestinal motility. SCF expression is here correlated with changes in mucosal morphology, acid and biliary reflux, and motility in the residual esophagus and gastric tube.

METHODS

Thirteen patients surgically resected for squamous esophageal carcinoma with gastric tube replaced by esophagogastric anastomosis underwent upper endoscopy, esophageal manometry, 24-hour pH monitoring, and bile reflux detection. Esophageal and gastric mucosa samples were examined for SCF expression by immunohistochemical and semiquantitative reverse transcriptase-polymerase chain reaction analysis and for SCF serum levels by enzyme-linked immunosorbent assay.

RESULTS

All patients showed severe residual esophagus hypoperistalsis and no gastric tube motor activity. The 24-hour pH monitoring was positive in most; 24-hour bile detection was mostly negative. SCF levels in the residual esophageal and gastric tube mucosa were dramatically decreased compared with those of normal subjects. The correlation between SCF and slow-wave activity was positive.

CONCLUSIONS

Hypomotility of the residual esophagus and gastric tube seems closely associated with disruption of the SCF/c-kit signaling pathway. However, the absence of notable relations between mucosal changes after chronic exposure to acid, biliary gastric content, and SCF expression indicates that this analysis cannot be considered part of endoscopic follow-up.

Immunologic and hematopoietic effects of recombinant human prolactin after syngeneic bone marrow transplantation in mice

The period of immune deficiency following bone marrow transplantation (BMT) results in a susceptibility to opportunistic infections and remains a growing obstacle in improving the efficacy of BMT. Neuroendocrine hormones have been shown to affect numerous immunologic and hematologic responses after in vivo administration. We investigated whether neuroendocrine hormones, notably prolactin (PRL), could be administered after BMT and result in improved immunologic recovery. Mice were given lethal total body irradiation followed with a congeneic or a syngeneic BMT. Some groups then received recombinant human PRL (rhPRL) daily for 3 weeks. Effects on immune reconstitution and function were then monitored. The results show that PRL could increase thymic cellularity and donor T-cell reconstitution after congeneic BMT. Increases in B cells and myeloid progenitors were also observed. Mitogenic responses by both T and B cells were observed after PRL treatment. These results suggest that PRL may be of use to promote immune and myeloid reconstitution after BMT.

Effect of prolactin on the antigen presenting function of monocyte-derived dendritic cells

Monocyte derived macrophages (Mphi) and dendritic cells (DC) play critical roles at the interface between innate and adaptive immunity. Both types of cells can effectively phagocytose exogenous antigens, whereas only DC can process and present them efficiently to antigen-specific T lymphocytes. The hormone PRL is also produced by immune cells and is regarded as a key component of the neuroendocrine--immune loop and a local regulator of lymphocyte response. Its main feature is cooperation with cytokines and hemopoietins. Triggering of monocyte PRL receptors with physiological-to-supraphysiological concentrations of PRL up-regulates the GM-CSF receptors, resulting in synergistic PRL-GM-CSF induced maturation of immature (i)DC. Further incubation induces increased antigen-presenting activity at the highest PRL concentrations studied (200 ng/ml). IFN-gamma, release by allogeneic lymphocytes is dependent on T cell-triggered IL-12 release by PRL-preincubated iDC. This, in turn, may be secondary to increased DC expression of CD40 or IFN-gamma. The permissive action of high PRL concentrations in the antigen presenting process may be of significance in initiation of the response against major histocompatibility complex (MHC)-presented self-antigens and may explain the association of hyperprolactinemia with autoimmune diseases.

Effects of prolactin on hematopoiesis

The presence of extra-pituitary prolactin and its cognitive receptors in the hematopoietic micro-environment raises the question of whether prolactin plays a role in lympho-hematopoiesis and under what conditions. Current studies suggest that endogenous prolactin does not play a significant role under normal steady-state conditions. Rather, prolactin has been implicated as a 'stress hormone', functioning to restore hematopoietic homeostasis under conditions of dysregulation. The stress response of prolactin as well as its complex relationship with other hormones and factors has resulted in conflicting reports in the literature regarding prolactin's role in lympho-hematopoiesis. A review of this literature is provided as well as discussion of conditions under which lymphohematopoietic activity of prolactin may be evident.