Wildfire particulate exposure and risks of preterm birth and low birth weight in the Southwestern United States

OBJECTIVES

Wildfire air pollution is a growing concern on human health. The study aims to assess the associations between wildfire air pollution and pregnancy outcomes in the Southwestern United States.

STUDY DESIGN

This was a retrospective cohort study.

METHODS

Birth records of 627,404 singleton deliveries in 2018 were obtained in eight states of the Southwestern United States and were linked to wildfire-sourced fine particulate matter (PM2.5) and their constituents (black carbon [BC] and organic carbon [OC]) during the entire gestational period. A double-robust logistic regression model was used to assess the associations of wildfire-sourced PM2.5 exposures and preterm birth and term low birth weight, adjusting for non-fire-sourced PM2.5 exposure and individual- and area-level confounder variables.

RESULTS

Wildfire-sourced PM2.5 contributed on average 15% of the ambient total PM2.5 concentrations. For preterm birth, the strongest association was observed in the second trimester (odds ratio [OR]: 1.06, 95% confidence interval [CI]: 1.05-1.07 for PM2.5; 1.06, 95% CI: 1.05-1.07 for BC; 1.04, 95% CI: 1.03-1.05 for OC, per interquartile range increment of exposure), with higher risks identified among non-smokers or those with low socio-economic status. For term low birth weight, the associations with wildfire-sourced PM2.5 exposures were consistently elevated for all trimesters except for the exposure averaged over the entire gestational period. Overall, the associations between wildfire-sourced PM2.5 and pregnancy outcomes were stronger than those with total PM2.5.

CONCLUSIONS

Wildfire-sourced PM2.5 and its constituents are linked to higher risks of preterm birth and term low birth weight among a significant US population than the effects of ambient total PM2.5.

Effect of low molecular weight heparin on bone metabolism and hyperlipidemia in patients on maintenance hemodialysis

The effect of low molecular weight heparin (LMWH) on serum lipid profile in hemodialysis remains controversial and its effect on bone metabolism has not been studied. A crossover study was conducted in 40 patients on stable hemodialysis using unfractionated heparin (UFH) for more than 24 months. These patients were then treated with a LMWH (nadroparin-Ca) for 8 months during hemodialysis and subsequently switched back to UFH for 12 months. Serum lipid profile, biochemical markers for bone metabolism, and bone densitometry (BMD) were monitored at four-month intervals while all medications remained unchanged. Cholesterol (TC), triglyceride (TG), low-density lipoprotein-cholesterol (LDL-C), lipoprotein(a) (Lp(a)), apolipoprotein B (Apo B) were raised in 35%, 29%, 12%, 24% and 24% of patients respectively. High-density lipoprotein-cholesterol (HDL-C) and apolipoprotein A1 (Apo A-1) were reduced in 47% and 9% of patients. Bone-specific alkaline phosphatase (BALP) and intact osteocalcin (OSC), both reflecting osteoblastic activity, were raised in 65% and 94% of patients. Tartrate-resistant acid phosphatase (TRACP) reflecting osteoclastic activity and parathyroid hormone (PTH) were elevated in 35% and 88% of patients. Following LMWH treatment, TC, Tg, Lp(a) and Apo B were reduced by 7%, 30%, 21% and 10% respectively (p<0.05 or <0.01) while Apo A-1 were raised by 7% (p<0.01). Simultaneously, TRACP was reduced by 13% (p<0.05). These biochemical changes were detected soon after 4 months of LMWH administration. Although BMD values in our patients were lower than those of age-matched normal subjects, significant changes were not observed with LMWH treatment. After switching back to UFH for hemodialysis, these biochemical indices reverted to previous values during UFH treatment with a significant higher level in TC and Apo B while serum Apo A-1 remained elevated. Our study suggests LMWH may partially alleviate hyperlipidemia and, perhaps, osteoporosis associated with UFH administration in patients on maintenance hemodialysis.

Efficacy of mycophenolate mofetil in patients with diffuse proliferative lupus nephritis. Hong Kong-Guangzhou Nephrology Study Group

BACKGROUND

The combination of cyclophosphamide and prednisolone is effective for the treatment of severe lupus nephritis but has serious adverse effects. Whether mycophenolate mofetil can be substituted for cyclophosphamide is not known.

METHODS

In 42 patients with diffuse proliferative lupus nephritis we compared the efficacy and side effects of a regimen of prednisolone and mycophenolate mofetil given for 12 months with those of a regimen of prednisolone and cyclophosphamide given for 6 months, followed by prednisolone and azathioprine for 6 months. Complete remission was defined as a value for urinary protein excretion that was less than 0.3 g per 24 hours, with normal urinary sediment, a normal serum albumin concentration, and values for serum creatinine and creatinine clearance that were no more than 15 percent above the base-line values. Partial remission was defined as a value for urinary protein excretion that was between 0.3 and 2.9 g per 24 hours, with a serum albumin concentration of at least 30 g per liter.

RESULTS

Eighty-one percent of the 21 patients treated with mycophenolate mofetil and prednisolone (group 1) had a complete remission, and 14 percent had a partial remission, as compared with 76 percent and 14 percent, respectively, of the 21 patients treated with cyclophosphamide and prednisolone followed by azathioprine and prednisolone (group 2). The improvements in the degree of proteinuria and the serum albumin and creatinine concentrations were similar in the two groups. One patient in each group discontinued treatment because of side effects. Infections were noted in 19 percent of the patients in group 1 and in 33 percent of those in group 2 (P = 0.29). Other adverse effects occurred only in group 2; they included amenorrhea (in 23 percent of the patients), hair loss (19 percent), leukopenia (10 percent), and death (10 percent). The rates of relapse were 15 percent and 11 percent, respectively.

CONCLUSIONS

For the treatment of diffuse proliferative lupus nephritis, the combination of mycophenolate mofetil and prednisolone is as effective as a regimen of cyclophosphamide and prednisolone followed by azathioprine and prednisolone but is less toxic.

Intraperitoneal pulse calcitriol in the treatment of secondary hyperparathyroidism in patients on continuous ambulatory peritoneal dialysis

OBJECTIVE

To determine whether it is practicable to use intraperitoneal calcitriol to treat continuous ambulatory peritoneal dialysis (CAPD) patients with secondary hyperparathyroidism and whether this form of therapy is effective and safe.

DESIGN

A prospective, nonrandomized study.

SETTING

Division of Nephrology, Tertiary Hospital.

METHOD

Eight patients from our CAPD population were recruited (5 F, 3 M), aged 24 to 63 years (mean 38.9 +/- 7.6 yr). They had been on CAPD for 8 to 84 months (mean 47.6 +/- 24.6 months). All the patients had bone biopsy-proven secondary hyperparathyroidism with 2 patients showing mixed lesions. The CAPD system was changed to the twin-bag system (Ultrabag, Baxter Healthcare, McGaw Park, IL, U.S.A.) in all 8 patients, who were taught to inject the calcitriol directly through the short transfer set and the Tenckhoff catheter into the peritoneal cavity, twice per week before bedtime. Calcium carbonate or calcium acetate was used as the main phosphate binder. Intact parathyroid hormone level (iPTH), serum ionized calcium (iCa), serum phosphate, and serum total alkaline phosphatase (alk. phos.) levels were measured at baseline and then every 4 weeks. The mean duration of follow-up was 10.5 months +/- 1.9 months.

RESULTS

There was a significant drop of iPTH level from the pretreatment level of 100.6 +/- 35.8 pmol/L to a level of 63.8 +/- 48.7 pmol/L at 24 weeks (p = 0.036). The lowest level of iPTH attained was 43.4 +/- 27.0 pmol/L at 48 weeks. Serum total alk. phos. also dropped from 232.4 +/- 83.3 IU/L pretreatment to 147.9 +/- 52.0 IU/L at 24 weeks (p = 0.017). The decrease in alk. phos. level paralleled the decrease in iPTH level. The mean serum iCa level did not show any significant rise throughout the study period. The maximum dose of calcitriol used was 6.6 +/- 1.5 microg/week and the average dose of calcitriol was 5.4 +/- 1.2 microg/week. One patient did not respond satisfactorily and she subsequently had a parathyroidectomy. Two episodes of peritonitis occurred during the study period, giving a peritonitis rate of one episode per 42 patient-months. There was no significant change in the urea clearance tests or the peritoneal equilibration tests before and after the study.

CONCLUSION

Intraperitoneal calcitriol is practicable, effective, and safe in the treatment of secondary hyperparathyroidism in CAPD patients.

Highly successful long-term outcome of kidney transplantation in Chinese recipients: an enhancing race effect?

We report on 352 cadaveric kidney transplants and 294 living related transplants performed over a 25-yr period among the Chinese population of Hong Kong. There is a marked preference for transplanting male patients, especially from living donors, and we argue that this represents a cultural phenomenon within the Chinese population. The 10-yr graft survivals for related and cadaveric transplants are 86.2% and 67.4%, respectively. These figures are appreciably higher than corresponding figures in Caucasian populations. We show beneficial effects of using cyclosporin A, minimizing the cold ischemia time and avoiding very young and very old donors. There is a clear benefit of transplanting kidneys with zero or one mismatched HLA antigen against the recipient but no stepwise decrease in outcome as the number of mismatched antigens increases. There is close concordance between the outcome of living related grafts with zero, one, and two mismatched haplotypes against the recipient and no observable benefit of haplotype matching. We show that Chinese renal transplant recipients in other centers also have better long-term graft outcome than Caucasians, both for cadaveric and living related transplants. We draw attention to the existence of a detrimental "race effect" in other studies when Black recipients are compared with Caucasians and consider whether an enhancing race effect exists for Chinese or whether the better outcome reflects different underlying diseases in Chinese.

Adult T cell leukaemia lymphoma in a non-aboriginal Australian woman with no apparent risk factors

OBJECTIVE

To present a case of adult T cell leukaemia lymphoma (ATLL) in a non-Aboriginal Australian woman with no apparent risk factor.

CLINICAL FEATURES

A 43-year-old Australian woman of European descent presented with a febrile illness associated with generalised lymphadenopathy and splenomegaly.

INVESTIGATIONS

There was lymphocytosis in the peripheral blood with a T helper cell phenotype. There were also lytic bone lesions with associated hypercalcaemia. HTLV-1 antibody was detected by agglutination assay and confirmed by western blot test.

TREATMENT AND OUTCOME

After initial response to CHOP chemotherapy (cyclophosphamide, doxorubicin, vincristine, prednisolone), she relapsed and died with central nervous system involvement eight months after the initial diagnosis.

CONCLUSION

To our knowledge this is only the third case of ATLL in a non-Aboriginal person in Australia.