Hypercalcaemia in patients with newly diagnosed tuberculosis in Malaysia

SETTING

University Hospital, Kuala Lumpur, Malaysia.

OBJECTIVE

To determine the incidence of hypercalcaemia in Malaysian patients with newly diagnosed tuberculosis (TB) before the commencement of antituberculosis treatment.

DESIGN

A prospective study of consecutive patients with newly diagnosed bacteriologically and/or histologically proven tuberculosis in our institution from September 1994 to March 1996.

RESULTS

Of a total of 120 patients (67 males, 53 females), 68 had pulmonary TB, nine had pulmonary and pleural TB, 18 had pleural TB without chest radiograph evidence of lung involvement, 16 had various other forms of extra-pulmonary TB and nine had disseminated TB. The mean age of the patients was 44.3 (+/-18.0) years. The mean albumin-adjusted serum calcium concentration was 2.53 (+/-0.22) mmol/l. Hypercalcaemia was present in 27.5% of the patients, but only 12% of these patients showed symptoms of hypercalcaemia. The type of TB and, in the case of pulmonary TB, the radiographic extent of lung involvement, had no effect on the serum calcium level.

CONCLUSION

Hypercalcaemia is not uncommon among Malaysian patients with newly diagnosed TB, but it is rarely symptomatic.

Long-term follow-up of two patients with metastatic neuroendocrine tumours treated with octreotide

Two patients are described with metastatic neuroendocrine tumours of the pancreas head and region of Vater. After surgery, administration of the long-acting somatostatin analogue octreotide was started. In the first patient we found an IgG-lambda paraproteinaemia and a parathyroid hormone-related protein (PTHrP) driven hypercalcaemia. By increasing the dose of octreotide the paraproteinaemia disappeared. In the second patient with a metastasized somatostatin producing neuroendocrine tumour, octreotide showed a long-term stabilizing effect on symptoms and progression of disease. The role of octreotide in the induction of changes in biological behaviour of malignant neuroendocrine cells is discussed.

Electrolyte quintet: Calcium

Abnormalities in serum calcium concentration may have profound effects on neurological, gastrointestinal, and renal function. Maintenance of the normal serum calcium is a result of tightly regulated ion transport by the kidney, intestinal tract, and bone, mediated by calcaemic hormones especially parathyroid hormone and 1,25-dihydroxyvitamin D3. Abnormalities in calcium transport that result in uncompensated influx into, or efflux from, the extracellular fluid, will result in hypercalcaemia or hypocalcaemia, respectively. When possible the biologically important ionised calcium concentration should be measured. A variety of common disorders are responsible for abnormalities in the serum calcium. Treatment of both hypercalcaemia and hypocalcaemia is dependent on the underlying disorder, the magnitude of the deviation of the serum calcium, and the severity of symptoms. Fortunately, in the case of hypercalcaemia, there is a broad selection of effective medications, especially the bisphosphonates. Treatment of hypocalcaemia relies on the provision of calcium and often vitamin D. In this article we review the mechanisms responsible for abnormalities in calcium homoeostasis, the differential diagnosis of hypercalcaemia and hypocalcaemia, and appropriate therapy.

Renal osteodystrophy in dialysis patients: diagnosis and treatment

This article reviews the clinical, biological, radiological, and pathological procedures and their respective indications for the practical diagnosis of the following various histological patterns of renal osteodystrophy: osteitis fibrosa due to parathyroid hormone (PTH) hypersecretion: osteomalacia or rickets due to native vitamin D deficiency and/or aluminum overload; and adynamic bone disease (ABD) due to aluminum overload and/or PTH secretion oversuppression. Our advice regarding bone biopsy is to restrict it to patients with symptoms and hypercalcemia, especially those who have been previously exposed to aluminum. In other cases, we propose relying merely on the determination of the plasma concentrations of calcium, protide, phosphate, bicarbonate, intact PTH, aluminum, 25(OH)D3, and alkaline phosphatase (total and bony if hepatic disease is associated) to choose the appropriate treatment. Because of the danger of the desferrioxamine treatment necessary to chelate and remove aluminum, the suspicion of aluminic bone disease (osteomalacia or ABD) will always be confirmed by a bone biopsy. In the case of nonaluminic osteomalacia, correction of the vitamin D deficiency by native vitamin D or 25(OH)D3, and of the calcium deficiency and acidosis by alkaline salts of calcium and if necessary sodium bicarbonate are sufficient to cure the disease. In the case of nonaluminic ABD, the stimulation of PTH secretion by the discontinuation of 1alpha hydroxylated vitamin D and the induction of a negative calcium balance during dialysis by decreasing the calcium concentration in the dialysate will allow an increase of the CaCO3 dose to correct for hyperphosphatemia without inducing hypercalcemia. For hyperparathyroidism, i.e., plasma intact PTH levels greater than two- or four-fold the upper limit of normal levels (according to the absence or presence of previous aluminum exposure), the treatment will consist in increasing the CaCO3 dose to correct for hyperphosphatemia together with a decrease of the calcium concentration in the dialysate if the dose of CaCO3 is so high that it induces hypercalcemia. When the hyperphosphatemia has been corrected and there is still a low or normal corrected plasma calcium level, 1alpha(OH)D3 in an oral bolus 2 or 3 times a week should be given at the minimal dose of 1 microg. When the PTH level stays above 400 pg while hypercalcemia occurs and hyperphosphatemia persists, surgical subtotal parathyroidectomy is recommended or the injection of calcitriol into the big nodular hyperplastic parathyroid glands under sonography control in high surgical risk patients. Special recommendations are given for children.

Reversible hypercalcemic cerebral vasoconstriction with seizures and blindness: a paradigm for eclampsia?

Although hypercalcemia may cause drowsiness, lethargy, weakness, confusion and coma it rarely causes seizures or cerebral infarction. The patient presented had a clinical evolution from hallucinosis to a generalized tonic-clonic seizure, and subsequent cortical blindness with occipital cerebral ischemia as evidenced by SPECT and MRI scans. EEG revealed occipital PLEDs. With reversal of hypercalcemia, there was a return of vision, resolution of EEG epileptiform activity, although with some residual occipital infarction. This case, in concert with a literature review of hypercalcemia, reveals examples of occipital and watershed ischemia, blindness, seizures and hypertension, a pattern markedly similar to that of eclampsia. Furthermore, medications such as magnesium sulfate, believed to reverse cerebrovasospasm responsible for the eclamptic neurologic findings, may counter the effects of hypercalcemia at a cellular level, lending support to a calcium-mediated injury in eclampsia.

Electrocardiographic abnormalities in combined hypercalcaemia and hypokalaemia--case report

A 47-year-old woman presented with extreme hypercalcaemia due to a parathyroid carcinoma. An electrocardiogram which was recorded when the hypercalcaemia was associated with hypokalaemia showed absence of the ST segment, prolonged T wave, a shortened QTac interval and prominent U waves.

[Differential diagnosis of hypercalcemia--a retrospective study of 46 dogs]

The case records of 46 dogs with hypercalcemia were studied retrospectively. The most common cause of hypercalcemia was malignancy, of which the majority were diagnosed as having lymphosarcoma (LSA, n = 23). Interestingly only 15 had palpable lymphadenopathy. Other neoplasia were apocrine adenocarcinoma of the anal sac (n = 4), mammary adenocarcinoma (n = 2), anaplastic carcinoma (n = 1), and malignant histiocytosis (n = 1). Non-neoplastic reasons for hypercalcemia were hypoadrenocorticism (n = 5), acute renal failure (n = 2), chronic renal failure (n = 2), hypervitaminosis D (n = 1), and primary hyperparathyroidism (n = 1). In 4 cases no definitive diagnosis could be obtained. Moderate to marked hyperphosphatemia and azotemia was found in all dogs with primary renal failure and in 4 of 5 dogs with hypoadrenocorticism. In contrast only 4 of 31 dogs with neoplasia showed (mild) hyperphosphatemia and 20 showed mild to moderate azotemia. Elevated PTH levels were found in dogs with primary chronic renal failure and with primary hyperparathyroidism, but also in one dog with neoplasia. Low PTH concentrations were measured in the dog with hypervitaminosis D and in 8 cases with neoplasia. Additional three cases with neoplasia had values in the reference range.

CONCLUSIONS

1. The most common cause of hypercalcemia is LSA. Absence of palpable lymphadenopathy does not exclude LSA and further diagnostic steps may be necessary 2. The combination of moderate to marked hyperphosphatemia suggests primary renal failure or hypoadrenocorticism. 3. An elevated PTH level is consistent with primary hyperparathyroidism, but does not exclude other causes of hypercalcemia.

[A diagnostic strategy in persistent hyperparathyroidism]

BACKGROUND

Primary operations for hyperparathyroidism performed by experienced surgeons has a success rate of about 95% without any preoperative localization. After unsuccessful cervicotomy, localization studies must be performed in order to define the surgical approach. The objective of our retrospective studies was to determine the accuracy of non invasive and invasive localization studies in patients with persistent hyperparathyroidism.

METHODS

The present reoperative series involved 7 patients with persistent hyperparathyroidism. Six patients came from a series of 140 operated on at the department of Prof. J. Marescaux from 1991 to 1993 (success rate of 95.7% in cervical exploration). Patient n. 7 came from another department.

RESULTS

After negative initial cervicotomy, non invasive localization procedure are undertaken, but with a high incidence of false-positive results (9% to 75%). Among available invasive techniques, it has been chosen to sample blood from large veins in the neck and mediastinum for Parathyroid Hormone (1-84 PTH) determination and to realise angiography for locating parathyroid adenomas as well as for vein mapping. Their combination permitted to localize all lesions.

CONCLUSIONS

The specificity of serum concentration of 1-84 PTH determination by catheterization of cervical and mediastinal veins (100%) combined to the sensitivity of angiography (82%) allowed to obtain good result in parathyroid localization in persistent hyperparathyroidism.

Hypercalcaemia with radiographic abnormalities in chronic myeloid leukaemia

Images

Verbal and nonverbal abilities in the Williams syndrome phenotype: evidence for diverging developmental trajectories

One commonly cited feature of Williams syndrome is a characteristic dissociation between relatively spared language skills and severely impaired nonverbal abilities. However, the actual evidence for a dissociation between verbal and nonverbal abilities in Williams syndrome is equivocal. In two separate studies we examined these abilities in 16 individuals showing the Williams syndrome phenotype. When considered as a whole, the group did have significantly superior verbal abilities, but this difference was caused by a large discrepancy in abilities in only a small number of individuals. In both studies there was a clear, linear relation between individuals' verbal ability, and the magnitude of their verbal-nonverbal discrepancy. We suggest that these results are best explained in terms of verbal ability developing at a faster rate than nonverbal ability in this disorder. We discuss how this model of differential rates of development has the potential to reconcile the apparently inconsistent findings in this area.

Lessons to be learned: a case study approach. Primary hyperparathyroidism simulating an acute severe polyneuritis

The case is presented of a 65 year old lady with recent onset of neuromuscular manifestations, comprising paraparesis, areflexia and unsteady gait, along with episodes of slurring of speech and diplopia, later confirmed to be due to severe hypercalcaemia--which itself was caused by primary hyperparathyroidism. Restoration of normocalcaemia, by means of rehydration and bisphosphonate therapy, resulted in clinical improvement--whilst subsequent parathyroidectomy was followed by complete resolution of all symptoms. In order to make prompt differentiation between the neurological sequelae of hyperparathyroidism and a primary neurological disorder, a high index of suspicion is required. An urgent serum calcium assay, as part of a bone profile, is mandatory in patients who present with neurological symptoms--especially the elderly, amongst whom hyperparathyroidism is especially common.

[Serum levels of carboxyterminal propeptide of type I procollagen (PICP), cross-linked carboxyterminal telopeptide region of type I collagen (ICTP) and carboxyterminal parathyroid hormone-related protein (C-PTHrP) in hematological malignancies with bone lesions and hypercalcemia]

We measured the levels of carboxyterminal propeptide of type I procollagen (PICP), cross-linked carboxyterminal telopeptide region of type I collagen (ICTP) and carboxyterminal parothyroid hormone-related protein (C-PTHrP) in serum of patients with hematological malignancies. ICTP and C-PTHrP levels in serum of multiple myeloma (MM), non-Hodgkin's lymphoma (NHL) and adult T-cell leukemia (ATL) patients with bone lesions and hypercalcemia were significantly higher than those of patients without bone lesions and hypercalcemia. ICTP and C-PTHrP levels in ATL were significantly higher than in MM and NHL. There was a correlation between ICTP and C-PTHrP in serum of ATL patients, but no correlation in MM and NHL. Serum ICTP levels tended to correlate with serum beta 2-microglobulin and survival in patients with MM. Therefore, ICTP and C-PTHrP levels in serum may be useful in the diagnosis of bone lesions and hypercalcemia in hematological malignancies. In particular, ICTP may be a useful bone resorption marker in MM.