乌鸦传媒

Patients with autoimmune diseases and certain other chronic conditions are at increased risk for shingles, a U.K. case-control study found.

Among risk factors for herpes zoster was systemic lupus erythematosus, with an odds ratio of 1.72 (95% CI 1.45-2.04), according to , and colleagues from the London School of Hygiene and Tropical Medicine.

In addition, an increased risk of more than 30% was seen for rheumatoid arthritis (RA) at OR 1.46 (95% CI 1.38-1.55) and chronic obstructive pulmonary disease (COPD) at OR 1.32 (95% CI 1.27-1.37), the researchers reported online in .

In the U.S. and Australia, the herpes zoster vaccine is recommended for individuals ages 60 and older, while in the U.K., it's generally available for those 70 and older.

"As the zoster vaccine is expensive, targeting vaccination towards groups at high risk of zoster is necessary. Age is the most important risk factor for zoster and postherpetic neuralgia, so it drives vaccination policies," Forbes and colleagues wrote.

But it's uncertain whether younger patients who might be at risk because of underlying disease also should receive the vaccine, despite .

Forbes and her team analyzed data from the Clinical Practice Research Datalink and Hospital Episodes Statistics, which include information about approximately 7% of the U.K. population, identifying 144,959 cases of herpes zoster and matching them with up to four controls.

Key risk factors other than lupus, RA, and COPD were inflammatory bowel disease, asthma, chronic kidney disease (CKD), diabetes, and depression.

Among cases of zoster, about 60% were in women, and median age at diagnosis was 62. A total of 65% of the cases were in patients younger than 70, and 45% were younger than 60.

The greatest risks were among patients with severe immunosuppression, such as those with HIV, lymphoma, and stem-cell transplants, but the vaccine is contraindicated in these groups.

"Alternative risk reduction strategies in these patients would help those at greatest risk of this disease and its complications," the researchers noted.

Among groups for whom the vaccine isn't contraindicated but are considered key risk factors in this analysis, an increased risk greater than 10% was seen for these conditions:

• Asthma: OR 1.11 (95% CI 1.06-1.16)
• CKD: OR 1.12 (95% CI 1.08-1.17)
• Depression: OR 1.15 (95% CI 1.10-1.19)

And while diabetes in general was not associated with zoster, an increased risk was found for type 1 diabetes (OR 1.26, 95% CI 1.06-1.49).

The investigators also adjusted for the effects of immunosuppressive treatments, and found that the increased risk persisted for lupus, RA, inflammatory bowel disease, asthma, and COPD, although to less of an extent than before adjustment.

They then considered the effects of age, and found that, in general, risks declined with older age. For example, the OR for zoster among patients with lupus ranged from 3.04 (95% CI 2.14-4.31) for those younger than 50 to 1.29 (95% CI 0.56-2.93, P<0.001) for those 70 and older.

For inflammatory bowel disease, the ORs were 1.73 (95% CI 1.47-2.03) among those younger than 50 and 1.18 (95% CI 0.81-1.70, P<0.001) for those 70 and older.

They also estimated absolute risks for shingles according to age groups, and found low rates for younger patients, but elevated rates for patients between 60 and 69 with RA (9.96 per 1,000 person-years), lupus (8.20 per 1,000), and COPD (9.19 per 1,000).

Finally, among all cases of zoster, 28.1% had at least one of the conditions considered risk factors of interest.

The researchers noted that the risk effects were pronounced even in younger patients. "This raises the question of whether vaccination of certain younger, high-risk groups may be beneficial; cost effectiveness studies, also considering the risk of postherpetic neuralgia, would be needed to answer this question," they wrote.

Limitations of the study included the possibility of ascertainment bias, residual confounding, or disease misclassification.