Insights Into the Role of Vitamin D as a Biomarker in Stem Cell Transplantation

Vitamin D was discovered 100 years ago and since then multiple studies have consistently proved its effect on bone health and mineral metabolism. Further research has also explored its so-called "non-classical" biological effects, encompassing immune regulation and control of cell proliferation and differentiation. Vitamin D downregulates pro-inflammatory immune cells and subsequently their cytokine production, while enhancing the anti-inflammatory subsets, thus mediating inflammation and fostering a more tolerogenic environment. Its biological action is exerted through the vitamin D receptor, a nuclear receptor that mediates gene transcription and is expressed in most cells from the innate and adaptive immunity. Owing to its immune-modulatory properties, its role in cancer pathophysiology, hematology disorders and stem cell transplantation has also been investigated. Vitamin D deficiency causes immune imbalance and cytokine dysregulation, contributing to some autoimmune diseases. In the hematopoietic stem cell transplant setting this could lead to complications such as acute and chronic graft-versus-host disease, ultimately impacting transplant outcomes. Other factors have also been linked to this, including specific polymorphisms of the vitamin D receptor in both stem cell donors and recipients. Nevertheless, studies thus far have shown conflicting results and the use of vitamin D or its receptor as biomarkers has not been validated yet, therefore there are no evidence-based consensus guidelines to guide clinicians in their day-to-day practice. To gain more insight in this topic, we have reviewed the existent literature and gathered the current evidence. This is an overview of the role of serum vitamin D and its receptor as biomarkers for clinical outcomes in patients undergoing hematopoietic stem cell transplantation. Further prospective studies with larger cohorts are warranted to validate the viability of using serum vitamin D, and its receptor, as biomarkers in potential stem cell donors and patients, to identify those at risk of post-transplant complications and enable early therapeutic interventions.

Halogen-like properties of the Al13 cluster mimicking astatine

Astatine-211 is considered to be one of the most promising alpha-emitters in targeted alpha therapy (TAT). However, its development has been hindered by its not so well understood chemistry. Hence, any attempt to understanding it better is imperative. Here, we show through DFT calculations that the neutral endohedral Al13 cluster follows a reactivity pattern very similar to At, more than any other halogen. The halogen and alkali bonding with Al13 and At presented a strong similarity in their charge transfer processes. Moreover, upon the interchange of At with Al13, we found a stable configuration of the compound corresponding to the astatination of aryliodonium salts, which have been considered as possible precursors for the synthesis of 211At-labeled tracers. Our results provide promising proof of concept that the Al13 cluster mimics the behaviour of At and might help in better understanding its chemistry and in streamlining the chemical processes of radiolabeling biomolecules.

Percutaneous mitral balloon valvotomy: six-year follow-up

OBJECTIVE

Percutaneous mitral valvotomy (PMV) is an alternative to the surgical treatment of mitral stenosis. Results obtained with PMV appear to depend on the echocardiographical characteristics of the valvular apparatus. The purpose of this study was to report the immediate and late-term results with PMV. The incidence of late events (restenosis, mitral valve replacement and death), and their correlation with echocardiographic score (Wilkin's score) are also discussed.

METHODS

Between December 1987 and August 1999, a total of 160 PMVs were performed at our institution. Ninety-six patients with a minimum of 6 months follow-up and echocardiographic evaluation of the mitral valve (Wilkin's score) before and after the procedure were selected for this study. Follow-up was available for 99% of the patients, with a mean follow-up of 33 +/- 22 months (range, 6 months to 11 years). Hazard ratio (HR) and Cox's regression were used for statistical analyses.

RESULTS

PMV was successfully performed in 97% of the cases; in 84%, the result was considered optimal. The incidence of complications related to the procedure was 10%; no mortality was observed due to PMV. Severe mitral regurgitation was observed in 7% of the patients, but only 3% of the total group developed ventricular dysfunction or worsened their New York Heart Association functional class. Eight-four percent of the patients were free of late events at the end of the follow-up period. A restenosis rate of 34% was observed during follow-up; this rate did not correlate with age, functional class or atrial fibrillation. Restenosis was associated with pulmonary hypertension (HR 2.85; 95% confidence interval, 0.68-11.80). Also, Wilkin's score was not useful to predict the development of restenosis or clinical events in the mid- to long-term.

CONCLUSION

In our series, PMV had a high immediate success rate and a low incidence of complications due to the procedure. Incidence of late events was also low and was unrelated to the Wilkin's score; however, recurrence of stenosis was observed in one-third. Pulmonary hypertension should be considered to be an important clinical predictor of restenosis.

[Endoscopic ligation plus sclerotherapy in esophageal varices treatment. Experience in active bleeding and in the elective treatment]

BACKGROUND

Endoscopic ligation is the treatment of choice for bleeding esophageal varices. The usefulness of additional sclerotherapy is not clear.

AIM

To assess the effectiveness of ligation followed by sclerotherapy in the treatment of variceal bleeding.

PATIENTS AND METHODS

Forty eight patients with variceal bleeding admitted for emergency treatment and 73 patients admitted for elective treatment were studied. Varices were ligated until a significant reduction in size was achieved. Eradication was completed with the injection of 1% polidocanol.

RESULTS

In 34 of 48 patients admitted for emergency treatment, the site of variceal rupture was identified. In all these subjects, and in 13 of 14 patients in whom the rupture site was not identified, hemorrhage was stopped with the procedure. Varices were eradicated in 108 of the 121 patients. Hemorrhage recidivated in 12.5% of patients admitted for emergency treatment, in a period of 14 months of follow up and in 9.6% of those admitted for elective treatment, in a period of 16 months follow up. Mortality was 14, 18 and 57% among patients classified as Child Pugh A, B or C, respectively.

CONCLUSIONS

Endoscopic ligation is effective in the treatment of variceal bleeding. Adding sclerotherapy, variceal eradication is achieved in a high percentage of patients. Survival depends on hepatic function.

Clinical benefit of noninvasive viability studies of patients with severe ischemic left ventricular dysfunction

The population of patients who have congestive heart failure of ischemic origin is large and growing. It imposes a heavy burden on human suffering and economic costs such as the chronic use of costly medications, recurrent hospital admissions, and, eventually, death or the necessity of heart transplantation. Therefore, the development of methods for detecting viable myocardium may allow the accurate selection of those patients with coronary artery disease with severe left ventricular dysfunction who are most likely to benefit from revascularization, but also excludes patients who are unlikely to obtain any improvement with revascularization techniques. The presence of reversible dysfunctional myocardium that may improve after revascularization implies the concepts of stunned and hibernating myocardium. Recent evidence suggests that hibernation may not be a stable condition since it might evolve toward an irreversible dysfunction if it is not revascularized at the right moment. The techniques available for viability studies are single-photon emission computed tomography using thallium-201 or compounds labeled with technetium-99m, positron emission tomography, and dobutamine stress echocardiography. Newer and promising techniques are magnetic resonance imaging and contrast echocardiography, whose definitive roles are not clear yet. There is abundant evidence from several important studies showing that patients with a significant amount of viable myocardium have a poor outcome if they are treated medically. Conversely, if these patients are revascularized, their outcomes improve and their symptoms significantly decrease, with less necessity of medication, fewer admissions to the hospital, and even in some cases avoiding heart transplantation. On the other hand, patients with poor or no viability who are revascularized do not obtain significant benefit.

[The hepatitis viruses: from A to TT]

A great progress in the knowledge about hepatitis virus has occurred in the last decades and several virus have been identified. Virus B, C and D are transmitted parenterally, while virus A and E use the enteral route. Highly effective vaccines for A and B hepatitis are presently available. Virus C is an important cause of chronic liver disease at the present moment. Since the identification of virus C and E, the number of acute hepatitis denominated as non A non B has decreased considerable. Although there are still patients with viral hepatitis of unknown origin and there is considerable effort to identify the agents causing them. Virus G and TT are frequently present in the sera of patients with chronic liver diseases but their real pathogenic role is not completely elucidated.

[Esophagogastric varix hemorrhage. Experience with cyanpoacrylate and polidocanol in 68 patients with active hemorrhage]

BACKGROUND

Sclerosis, injection of cianoacrylate and rubber band ligation are the most commonly used endoscopic techniques for the treatment of bleeding esophageal varices.

AIM

To assess the effectiveness of cianoacrylate and polidocanol in the treatment of bleeding esophageal varices.

PATIENTS AND METHODS

Sixty eight patients with active variceal bleeding were studied. Bleeding varices were classified as thin, thick or gastric. Bleeding from thin varices was treated with polidocanol. Bleeding from thick or gastric varices was treated with cianoacrylate. Variceal eradication was done with polidocanol.

RESULTS

Bleeding came from thin esophageal varices in 23% of patients and endoscopic treatment stopped bleeding in 95% of them, from thick esophageal varices in 62% and endoscopic treatment was successful in 94% of these, and from gastric varices in 12% and treatment stopped bleeding in 87% of these (in 3% bleeding was considered subcardial). Twenty-five percent of patients bled again during variceal eradication, 12% died due to uncontrollable bleeding and 20% died due to liver failure. During variceal eradication 59% of patients classified as Child Pugh C, died.

CONCLUSIONS

Treatment of bleeding esophageal varices with cianoacrylate or polidocanol is effective. Patients classified as Child Pugh C have a had prognosis.

[Porphyrin excretion in patients with chronic hepatitis C virus infection]

BACKGROUND

The high prevalence of chronic hepatitis C virus infection in patients with porphyria cutanea tarda, specially in those without family history of the disease, suggests that this could be an acquired disease and one of the most frequent extra hepatic manifestations of hepatitis C virus infection.

AIM

To study the excretion of porphyrins and its precursors in cirrhotic patients with and without hepatitis C virus infection.

PATIENTS AND METHODS

Eighteen patients with cirrhosis Child-Pough A, eight infected with hepatitis C virus, were studied. Urinary excretion of [symbol see text] aminolevulinic acid, porphobilinogen, coproporphyrins, uroporphyrins and fecal excretion of coproporphyrins and protoporphyrins were measured. Red blood cell protoporphyrin was also measured.

RESULTS

There were no differences in the measured parameters between patients with or without hepatitis C virus infection. No patient had uroporphyrin excretion values over the normal range. Some patients had slight elevations in some parameters, but always below the values observed in porphyrias.

CONCLUSIONS

In these group of patients, hepatitis C virus infection of its associated liver disease, do not cause detectable alterations in porphyrin metabolism.

Use of a very flexible guide wire to permit dilation of complex malignant strictures of the esophagus

Risk of perforation is a major impediment to the use of polyvinyl bougies in palliative dilation of cancerous strictures of the esophagus. We encountered 23 patients with complex malignant strictures in whom initial dilation with Savary-Gilliard bougies was thwarted because attempts to pass a conventional Eder-Puestow guide wire were unsuccessful. As a recourse, we probed these strictures with a very flexible guide wire of the type used to implant prostheses in the biliary tract. The purpose was to establish a passage through which a standard guide wire could then be inserted. The procedure was successful in all but 4 of the 23 patients. We conclude that in such cases the preliminary use of the very flexible guide, even though time-consuming, improves the chance of effective dilation with minimal added risk.

[Prevention of digestive hemorrhage recurrence in hepatic cirrhosis with propranolol. A 4 years' follow-up study]

The aim of this study was to assess the effect of propranolol treatment on the recurrence of variceal bleeding and mortality in patients with hepatic cirrhosis. Fifty seven patients were studied; they were recruited within 15 days of an episode of variceal bleeding, assigned randomly to receive propranolol (n = 29) placebo (n = 28) and followed during 4 years. Three patients were lost from follow up and in 3 propranolol was discontinued due to secondary effects. Bleeding recurrence was less frequent in the treated patients (Kaplan Meier analysis p < 0.01). Ten patients on placebo and 1 receiving the active drug died. Life table analysis showed a significantly better survival in the group of patients treated with propranolol. It is concluded that propranolol decreases the recurrence of variceal bleeding and improves survival in patients with hepatic cirrhosis.

[Prevalence of hepatitis C virus antibodies in a hemodialysis unit]

The prevalence of hepatitis C antibody was studied using the EIA 2 Abbott assay in patients and staff of the San Juan de Dios Hospital Hemodialysis Unit. The antibody was detected in 29.8% of patients, no member of the staff had positive antibodies. Patients with a positive antibody had been on hemodialysis for a longer time than those with a negative test (53.3 +/- 18.8 vs 37.9 +/- 33.5 months respectively). No differences in the number of transfusions received were observed between patients with positive or negative antibodies. Hepatitis B surface antigen was detected in 2 patients, with negative hepatitis C virus antibody. No clinical evidence of liver disease was found among patients with positive antibodies.

[Hepatitis C virus antibodies in chronic non-alcoholic liver disease]

The presence of hepatitis C virus antibodies was studied in 64 patients with non alcoholic liver disease and found in 11 (17%). The greater frequency of positive antibodies was found among patients with cryptogenetic liver disease, specially those without serum auto-antibodies (32%). The antibody was unusually found (0 to 11%) in non alcoholic liver diseases of other etiologies. It is concluded that hepatitis C virus chronic infections may be the etiology of an important number of non alcoholic chronic liver diseases.

[Poems syndrome: review of a case]

POEMS (acronym for polyneuropathy, organomegaly, endocrinopathy, M protein and skin changes) is a very rare syndrome probably related to plasma cell dyscrasia. A 43 year old man developed a progressive symmetric sensory motor polyneuropathy 2 years before admission. Hepatosplenomegaly and sclerodermatoid skin changes were present on physical examination. A sclerotic lesion of the right femur was disclosed by radiologic examination. Serum immunoelectrophoresis demonstrated a monoclonal protein IgG-lambda pattern and the bone marrow biopsy revealed an increased plasma cell count (15%). The patient died 7 months after admission from pneumonia. A review of the literature is included.

[Primary hyperparathyroidism: usefulness of high resolution echography in local diagnosis]

Recent reports show a better surgical outcome in primary hyperparathyroidism when an accurate preoperative localization of the lesion in available. We performed high resolution sonography in 23 consecutive patients (20 women) with biochemically proven hyperparathyroidism. Twenty two of them were operated on and their sonographic reports were compared to the surgical and pathological findings (20 adenomas, 1 carcinoma and 1 hyperplasia). One patient did not have surgery but the sonogram was compared to a Tl 201-Tc99 scintigram that suggested an adenoma. Sonography showed a single parathyroid tumor in 17 patients and failed to demonstrate a lesion in six. There were two false positives and 6 false negatives. The sensitivity was 71.5% and the positive predictive value was 88%. Three out of 6 patients with a negative sonography had an adenoma located out of reach for the method. Our results show that the high resolution sonography is a useful, non invasive method to localize abnormally enlarged parathyroid glands in hyperparathyroidism and we think it should be performed in every patient with a biochemical diagnosis of this disease.

Relationship between hepatic levels of glutathione and sulphobromophthalein retention in hyperthyroidism

1. Sulphobromophthalein (BSP) retention and liver glutathione levels were studied in uncomplicated hyperthyroid patients. 2. BSP retention was increased in 52.5% of the subjects at admission (n = 40) and in 28% of the cases after 3 months of propylthiouracil treatment (300-400 mg/day) (n = 25). 3. Hepatic levels of glutathione were measured in six patients and significant inversed power correlation with BSP retention was observed (r = 0.968, P less than 0.001). 4. These data support the contention that the alteration of the BSP retention observed in hyperthyroidism could be due to a decreased availability of hepatic glutathione for conjugation.

Tru-cut and Menghini needles: different yield in the histological diagnosis of liver disease

An evaluation of the information obtained by percutaneous liver biopsy performed with Travenol Tru-cut ("Tru-cut"), Menghini's 1.9 and 1.6 needles, was done using cadavers. All needles used had a similar, low number of "failures". Recognition of diffuse liver lesions, excluding fibrosis, was very high regardless of the needle used. Identification of cirrhosis was significantly more frequent in biopsies performed with the Tru-cut needle.

Massive pleural effusions in cirrhotic patients with ascites

A method is described based on the passage of air across the diaphragm to detect pathological diaphragmatic orifices in autopsies. This method was used in 65 post-mortem studies; orifices were detected in 7 cases. Only one of these appears histologically to be a real spontaneous orifice. This was found in the post-mortem study of a cirrhotic patient with ascites and massive and recurrent hydrothorax. In eight patients with cirrhotic ascites and pleural effusions, radioisotopes were introduced into the ascites fluid, and only in two of them, both with right massive and recurrent pleural effusion, was radioactivity detected in the pleural cavity within the 1st h after injection. The radioisotopic method for detecting in vivo these orifices avoids the repeated taps that are necessary when dyes are used.