Mycobacterial infections in adults with haematological malignancies and haematopoietic stem cell transplants: guidelines from the 8th European Conference on Infections in Leukaemia

Mycobacterial infections, both tuberculosis and nontuberculous, are more common in patients with haematological malignancies and haematopoietic stem cell transplant recipients than in the general population-although these infections remain rare. Mycobacterial infections pose both diagnostic and therapeutic challenges. The management of mycobacterial infections is particularly complicated for patients in haematology because of the many drug-drug interactions between antimycobacterial drugs and haematological and immunosuppressive treatments. The management of mycobacterial infections must also consider the effect of delaying haematological management. We surveyed the management practices for latent tuberculosis infection (LTBI) in haematology centres in Europe. We then conducted a meticulous review of the literature on the epidemiology, diagnosis, and management of LTBI, tuberculosis, and nontuberculous mycobacterial infections among patients in haematology, and we formulated clinical guidelines according to standardised European Conference on Infections in Leukaemia (ECIL) methods. In this Review, we summarise the available literature and the recommendations of ECIL 8 for managing mycobacterial infections in patients with haematological malignancies.

The effect of prepubertal calcium carbonate supplementation on skeletal development in Gambian boys-a 12-year follow-up study

CONTEXT

Calcium intake during growth is essential for future bone health but varies widely between individuals and populations. The impact on bone of increasing calcium intake is unknown in a population where low calcium intake, stunting, and delayed puberty are common.

OBJECTIVE

To determine the effect of prepubertal calcium supplementation on mean age at peak velocity for bone growth and mineral accrual.

DESIGN AND SETTING

Prospective follow-up of boys in rural Gambia, West Africa, who had participated in a double-blind, randomized, placebo-controlled trial of calcium supplementation.

PARTICIPANTS

Eighty boys, initially aged 8.0-11.9 years, were followed up for 12 years.

INTERVENTIONS

Subjects received 1 year of calcium carbonate supplementation (1000 mg daily, 5 d/wk).

MAIN OUTCOME MEASURES

Dual-energy x-ray absorptiometry measurements were carried out for whole body (WB), lumbar spine, and total hip bone mineral content, bone area (BA), and WB lean mass. Super imposition by translation and rotation models was made to assess bone growth.

RESULTS

Age at peak velocity was consistently earlier in the calcium group compared to the placebo group, for WB bone mineral content (mean, -6.2 [SE, 3.1]; P = .05), WB BA (mean, -7.0 [SE, 3.2] mo; P = .03), lumbar spine and total hip BA. By young adulthood, supplementation did not change the amount of bone accrued (mineral or size) or the rate of bone growth.

CONCLUSIONS

Twelve months of prepubertal calcium carbonate supplementation in boys with a low calcium diet advanced the adolescent growth spurt but had no lasting effect on bone mineral or bone size. There is a need for caution when applying international recommendations to different populations.

Toxoplasmosis following alemtuzumab based allogeneic haematopoietic stem cell transplantation

Alemtuzumab is a humanised monoclonal antibody against CD52 used as an immunosuppressive agent in allogeneic HSCT. Regimens including alemtuzumab for allogeneic haematopoietic stem cell transplant (HSCT) conditioning have been associated with an increased incidence of viral complications. Patients with prior toxoplasma exposure undergoing alemtuzumab containing HSCT could therefore be expected to be at a higher risk of toxoplasma reactivation. We conducted a retrospective review of 220 alemtuzumab based allogeneic HSCT performed over a 4 year period, of which 202 were reduced intensity conditioning (RIC) HSCT. A total of 67 patients (30%) in whom the pre-transplant recipient toxoplasma IgG test was positive were classified as high-risk for toxoplasma infection. All patients started trimethoprim/sulfamethoxazole prophylaxis following HSCT when the neutrophil count was > or = 1x10(9)/l. Two high-risk patients developed toxoplasma invasive disease with cerebral involvement at 2 and 4 months post-transplantation respectively. The incidence of toxoplasma disease in the entire cohort and amongst high-risk patients was 0.9% and 3.0% respectively. Despite in vivo T-cell depletion with alemtuzumab, the incidence of toxoplasma disease in our cohort was comparable with previously reported T-cell replete HSCT studies.

Effect of calcium supplementation on bone mineral accretion in gambian children accustomed to a low-calcium diet

BACKGROUND

Rural Gambian children have poor growth, delayed puberty, a low bone mineral content, and a low calcium intake.

OBJECTIVE

We investigated the effect of a calcium supplement on bone mineral accretion in rural Gambian children.

DESIGN

A randomized, double-blind, placebo-controlled study was conducted in 160 children (80 boys, 80 girls) aged 8.3-11.9 y. Bone mineral content (BMC), bone mineral density (BMD), and BMC adjusted for bone width, body weight, and height (size-adjusted BMC) were measured at the midshaft and distal radius. Each child received either 1000 mg Ca/d (as calcium carbonate) or a placebo 5 d/wk for 12 mo. Supplementation increased calcium intake from 342 to 1056 mg/d (8.6 to 26.4 mmol/d).

RESULTS

Calcium supplementation resulted in a higher BMC, BMD, and size-adjusted BMC (&xmacr; difference +/- SE): midshaft radius-BMC (3.0 +/- 1.4%; P = 0.034), BMD (4.5 +/- 0.9%; P </= 0.0001), and size-adjusted BMC (4.6 +/- 0.9%; P </= 0.0001); distal radius-BMC (8. 4 +/- 3.2%; P = 0.009), BMD (7.0 +/- 2.7%; P = 0.011), and size-adjusted BMC (5.5 +/- 2.7%; P = 0.042). Supplementation had no significant effect on height, weight, or bone width at the midshaft radius or distal radius. At the end of the study, the calcium group had a significantly lower mean plasma osteocalcin concentration than the placebo group after adjustment for baseline concentration, sex, and pubertal status (-21.9 +/- 6.5%; P = 0.001).

CONCLUSIONS

Increased calcium intake resulted in increased bone mineral status, possibly in association with a decreased bone remodeling space. Further studies are needed to determine whether an increased calcium intake has long-term benefits in Gambian children.