Mineralocorticoid deficiency in HIV infection

Case control study: magnetic resonance spectroscopy of brain in HIV infected patients

BACKGROUND

In vivo proton magnetic resonance spectroscopy ((1)H-MRS) studies on brain in HIV infected patients have shown significant alteration in neuro-biochemicals.

METHODS

In this study, we measured the neuro-biochemical metabolites from the left frontal white matter (FWM) and left basal ganglia (BG) caudate head nucleus in 71 subjects that include 30 healthy controls, 20 asymptomatic HIV and 21 HIV patients with CNS lesion. Proton MR spectra were acquired at 3 T MRI system and the concentration (institutional units) of tNAA (N-acetylaspartate, NAA + N-acetylaspartylglutamate, NAAG), tCr (Creatine, Cr + phosphocreatine, PCr), choline containing compounds (tCho), glutamate + glutamine (Glx) and lipid and macromolecules at 0.9 ppm were determined using LC Model.

RESULTS

In BG, the concentration of tNAA (6.71 ± 0.64) was decreased and in FWM, the concentration of Glx (20.4 ± 7.8), tCr (9.14 ± 3.04) and lipid and macromolecules at 0.9 ppm (8.69 ± 2.96) were increased in HIV patients with CNS lesion. In healthy controls, the concentration of tNAA in BG was 7.31 ± 0.47 and concentration of Glx, tCr and lipid and macromolecules in FWM were 15.0 ± 6.06, 6.95 ± 2.56, 5.59 ± 1.56, respectively.

CONCLUSION

Reduced tNAA in BG suggests neuronal loss in HIV patients with CNS lesion while increased Glx in FWM may suggest excito-toxicity. In addition, increased levels of tCr in FWM of HIV patients were observed. The study indicates region specific metabolic changes in tNAA, tCr and Glx in brain of HIV infected patients.

HIV associated hypocalcaemia among diarrheic patients in northwest Ethiopia: a cross sectional study

BACKGROUND

Hypocalcaemia, defined by serum calcium level less than 8.5 mg/dl, could be caused by human immunodeficiency virus (HIV) and diarrheal diseases. In Ethiopia, while morbidities from diarrheal diseases and HIV are serious health problems, studies assessing the interactions amongst of the three do not exist. Therefore, the present study was undertaken to investigate the level of calcium among diarrheic patients with and without HIV co-infection.

METHODS

Consecutive diarrheic patients attending Gondar University Hospital in Ethiopia were enrolled and screened for HIV, intestinal parasites, Shigella and Salmonella. Concentration of calcium in serum was determined using an inductively coupled plasma mass spectrometer.

RESULTS

A total of 206 diarrheic patients were included in the study (109 = HIV positive, 97 = HIV negative). Intestinal parasites and Shigella species were detected in 32.2% and 8.5% of the patients, respectively. The serum calcium levels in the patients who were found positive for Shigella species or intestinal parasites was not significantly different by the presence or absence of HIV co-infection. HIV infected diarrheic patients had significantly lower mean serum calcium levels (7.82 ± 1.23 mg/dl) than those negative for HIV (8.38 ± 1.97) (P = 0.015). The age groups 25-35 and greater than 45 years showed significantly lower mean serum calcium levels (7.77 ± 1.55 mg/dl) in comparison to the other age groups (7.84 ± 1.41 mg/dl, P = 0.009). On the other hand, females presented with significantly lower mean serum calcium levels (7.79 ± 1.60 mg/dl, P = 0.044) than males (8.26 ± 1.65 mg/dl).

CONCLUSION

There is high prevalence of hypocalcaemia among diarrheic patients in northwest Ethiopia. And HIV stood out to be a major risk factor for development of hypocalcaemia among the diarrheic patients in northwest Ethiopia. Further studies are required to substantiate and characterize the mechanisms and consequences of calcium metabolism disorders among HIV infected individuals in the study area.

Changing electrolyte and acido-basic profile in HIV-infected patients in the HAART era

BACKGROUND

HIV-infected patients may develop a variety of underreported metabolic abnormalities that may be classified into HIVAN, specific HIV abnormalities, coincidental renal disorders and anti-retroviral-treatment-induced side effects.

METHODS

Our descriptive cross-sectional study evaluates the prevalence of electrolyte and acid base disorders in HIV patients in the HAART era in a tertiary care teaching hospital. All consecutive HIV-infected patients (n = 1,232) presenting at our Department of Infectious Disease over 3 months were included.

MEASUREMENTS

All available biochemical data obtained at admission or on the day of the visit were analyzed. We identified risk factors for electrolyte and acid base disorders with univariate regression analysis and multivariate stepwise regression analysis. Variables tested for significance included age, sex, absolute CD4 and CD8 counts, hepatitis B and C antibodies, and use and type of anti-retroviral medication.

RESULTS

Most frequent and clinically relevant abnormalities were hyperuricemia in 41.3%, hypophosphatemia in 17.2% and low bicarbonate level in 13.6% of HIV-tested patients. Plasma magnesium was out of the normal range in 38.9% and blood glucose in 25.3% of the tested patients. When CD4 count was below 200/mm3, 9.2% of tested patients experienced low serum calcium (vs. 0.5% if CD4 count >200/mm3, p < 0.002), 11.4% increased creatinine plasma level (vs. 2.3% if CD4 count >200/mm3, p < 0.0001) and 24.5% low serum bicarbonate (vs. 13.7% if CD4 count >200/mm3, p < 0.0001). Protease inhibitor treatment was a significant risk factor of hyperuricemia (p < 0.003). Non-nucleoside reverse transcriptase inhibitor therapy was significantly associated with less hyperuricemia (OR = 0.6, 95% CI 0.38-0.96) and with hypophosphatemia (OR = 2.0, 95% CI 1.1-3.4).

CONCLUSIONS

The profile of biochemical abnormalities in HIV-infected patients has changed, hyperuricemia and hypophosphatemia being the most prevalent. Causes are poorly understood. Interpretation of drug-induced side effects in the HIV patient is only meaningful if performed versus a control group of patients.

Hyper- and hypoaldosteronism

Aldosterone participates in blood volume and serum potassium homeostasis, which in turn regulate aldosterone secretion by the zona glomerulosa of the adrenal cortex. Autonomous aldosterone hypersecretion leads to hypertension and hypokalemia. Improved screening techniques have led to a re-evaluation of the frequency of primary aldosteronism among adults with hypertension, recognizing that normokalemic cases are more frequent than was previously appreciated. The genetic basis of glucocorticoid remediable aldosteronism has been elucidated and adequately explains most of the pathophysiologic features of this disorder. A new form of familial aldosteronism has been described, familial hyperaldosteronism type II; linkage analysis and direct mutation screening has shown that this disorder is unrelated to mutations in the genes for aldosterone synthase or the angiotensin II receptor. The features of aldosterone hypersecretion may be due to non-aldosterone-mediated mineralocorticoid excess. These include two causes of congenital adrenal hyperplasia (11 beta-hydroxylase deficiency and 17 alpha-hydroxylase deficiency), the syndrome of apparent mineralocorticoid excess (AME) due to 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD) deficiency, primary glucocorticoid resistance, Liddle's syndrome due to activating mutations of the renal epithelial sodium channel, and exogenous sources of mineralocorticoid, such as licorice, or drugs, such as carbenoxolone. The features of mineralocorticoid excess are also often seen in Cushing's syndrome. Hypoaldosteronism may lead to hypotension and hyperkalemia. Hypoaldosteronism may be due to inadequate stimulation of aldosterone secretion (hyporeninemic hypoaldosteronism), defects in adrenal synthesis of aldosterone, or resistance to the ion transport effects of aldosterone, such as are seen in pseudohypoaldosteronism type I (PHA I). PHA I is frequently due to mutations involving the amiloride sensitive epithelial sodium channel. Gordon's syndrome (PHA type II) is due to resistance to the kaliuretic but not sodium reabsorptive effects of aldosterone for which the genetic basis is still unknown. This review aims to provide a survey of the clinical disorders of aldosterone excess and deficiency and their clinical management, with a focus on primary aldosteronism and isolated aldosterone deficiency.

Endocrinologic complications of HIV infection

A variety of endocrine disorders occur in HIV-infected patients. The abnormalities may be a consequence of HIV infection, or may result from opportunistic infections, associated malignancies, illness-associated cytokine production, or use of therapeutic agents. Observations and controversies concerning adrenal, gonadal, thyroidal, and metabolic abnormalities are discussed. Heightened awareness of problems that might otherwise be overlooked will permit timely diagnosis and treatment of identified problems, which will enhance and potentially prolong the lives of people infected with HIV.

Endocrine implications of human immunodeficiency virus infection

Endocrine abnormalities occur frequently in HIV-infected patients. Although the majority of endocrine disorders reflect chronic infection, stress, and malnutrition, some disorders are characteristic of HIV infection or AIDS and deserve particular clinical attention. Identification of HIV patients at risk of frank endocrine disorders, rapid and correct diagnosis, and appropriate management are essential steps to minimize morbidity and mortality. Finally, increasing evidence from in vitro studies suggests that various hormones may influence HIV replication as well as the course of HIV disease and associated disorders. Future studies on the molecular mechanisms of hormones on HIV action and clinical studies on the effects of hormones as adjunctives to established forms of therapy may stimulate development of novel therapeutic strategies that will benefit HIV-infected patients.

Effect of standard-dose trimethoprim/sulfamethoxazole on the serum potassium concentration in elderly men

OBJECTIVE

To determine the effect of standard-dose trimethoprim/sulfamethoxazole (TMP/SMX) (TMP 160 mg and SMX 800 mg q12h) on the serum potassium concentration.

DESIGN

Retrospective and concurrent study.

SETTING

A Veterans Affairs Medical Center.

PATIENTS

Fifty-three men hospitalized at the Fargo Veterans Affairs Medical Center. Thirty-three patients who received standard-dose TMP/SMX for 3 or more days comprised the study group. Twenty patients who received oral cephradine or amoxicillin for 3 or more days comprised the control group. Patients who received potassium supplements, potassium-sparing diuretics, angiotensin-converting enzyme inhibitors, nonsteroidal antiinflammatory drugs, beta-blockers, heparin, known nephrotoxic agents, patients with a serum creatinine concentration of more than 177 mumol/L, and patients with baseline hyperkalemia (serum potassium concentration > 5.1 mmol/L) were excluded.

RESULTS

The serum potassium concentration in the study group was 4.22 +/- 0.40 mmol/L and increased by 0.31 +/- 0.38 mmol/L at the end of therapy (p < 0.001). Twenty-six patients in the study group (78.8%) had an increase in the serum potassium concentration during TMP/SMX therapy. Fourteen of these patients had follow-up serum potassium concentrations obtained after completion of therapy. The serum potassium concentration returned to baseline in 10 of these patients. The serum creatinine concentration also increased during therapy. However, the correlation between the increase in the serum potassium concentration and the increase in the serum creatinine concentration was weak (Pearson r = 0.29). The serum potassium in the control group was 4.34 mmol/L and remained essentially unchanged during therapy.

CONCLUSIONS

Therapy with standard-dose TMP/SMX is associated with a slight increase in the serum potassium concentration. Routine monitoring of the serum potassium concentration in patients who are treated with standard-dose TMP/SMX therapy is unnecessary. However, TMP/SMX should be considered as a possible cause of unexplained hyperkalemia in elderly patients receiving TMP/SMX therapy.

Hyperkalemia with high-dose trimethoprim-sulfamethoxazole therapy

In a patient with the acquired immunodeficiency syndrome, a progressive increase in the serum potassium concentration occurred with high-dose trimethoprim-sulfamethoxazole (TMP-SMX) therapy for Pneumocystis carinii pneumonia. In this patient, factors known to alter transcellular potassium shifts to induce hyperkalemia were not present. There was no evidence of glucocorticoid or mineralocorticoid insufficiency at the time of hyperkalemia, while the transtubular potassium gradient decreased. The hyperkalemia resolved spontaneously on discontinuation of TMP-SMX therapy, suggesting that this electrolyte abnormality is related to altered renal tubular secretion of potassium as a consequence of the high-dose TMP-SMX therapy.

The adrenal gland in AIDS

The adrenal gland has been known to be a common site of opportunistic infections and tumors that define the acquired immunodeficiency syndrome (AIDS) ever since the first autopsy data were published. We have examined the adrenal glands of 66 AIDS patients autopsied in New York City and tabulated and graded the findings in an attempt to estimate the likelihood of adrenal insufficiency developing on the basis of these lesions. AIDSdefining conditions were found in the adrenal glands of 56% of patients, primarily opportunistic infections (53%) and much less frequently neoplasms (3%). Cytomegaloviral (CMV) infection was by far the most common type (42%), followed by mycobacterial (8%) and fungal infections (3%). There was one case eachof Kaposi's sarcoma and lymphoma. Total necrosis of adrenal cortex was restricted to 2 cases of tuberculosis. CMV adrenalitis, although the most common infection and often associated with necrosis, never resulted in more than 30% destruction of the cortex. We conclude that although histopathological evidence of adrenal disease is common in AIDS, most such lesions are not sufficiently extensive to result in adrenal insufficiency. In contrast to previous reports stressing the importance of CMV adrenalitis as a possible cause of adrenocortical insufficiency, we now find tuberculosis the more likely cause of total cortical destruction.

Adrenal gland: chemically induced structural and functional changes in the cortex

The adrenal cortex is the target of a surprisingly large number of exogenous chemicals. Until recently, the toxic action of these chemicals was discovered serendipitously. Following our observations that acrylonitrile, cysteamine or pyrazole induces hemorrhagic adrenocortical necrosis in the rat, we recently recognized a structure-activity correlation which predicts the adrenocorticolytic property of alkyl chemicals, i.e., 2-3 carbons with double or triple bonds and with nucleophilic terminal radicals (e.g., -CN, -SH, -NH2). On the basis of our results obtained with electron microscopic, histochemical and biochemical studies as well as those of others, we propose the following sequence of events in the pathogenesis of chemically induced adrenocortical necrosis: 1) Depletion of glutathione and increased dopamine concentration in the adrenals; 2) Endothelial damage and rupture of capillary walls in the adrenal cortex due to either direct attack by the chemicals (metabolites) and/or released monoamines; 3) Retrograde embolization of medullary tissue fragments into the cortical capillaries; 4) Enhanced destruction of cortical vascular walls with subsequent platelet aggregation, fibrin deposition which is often associated with a systemic drop in platelet counts, and changes in blood coagulation; 5) Escape of plasma and cellular elements of blood into extravascular spaces and damage of adrenocortical parenchymal cells; and 6) Hemorrhage and necrosis in the adrenal cortex. This pathogenetic sequence was investigated in detail with acrylonitrile, and studied in various aspects with thioguanine, cysteamine and pyrazole.