本帖最後由 lsc0019 於 2009-5-12 01:05 編輯
作者：Neil Osterweil
出處：WebMD醫學新聞
April 28, 2009（法國巴黎）－根據一項發表在國際心臟與肺臟移植第29屆年會與科學座談會上的研究報告，有五個以上小孩的女性，如果她需要心臟移植的話，可能會縮短她的存活時間。
主要研究者、田納西州奈許威利Vanderbilt大學心臟血管部門的臨床研究員Cheri Silverstein醫師表示，懷孕可能是一年內急性排斥反應風險的獨立危險因子。
Silverstein醫師指出，排斥反應風險顯然獨立於胎兒抗原敏感反應之外。
Silverstein醫師表示，接受原位心臟移植的女性，相較於男性，發生排斥反應的風險顯然較高，且較小型的研究結果顯示，懷孕兩次以上女性的一系列反應抗體（PRA）上升風險尤其增加，這是一種排斥反應的標記。
為了確認累積懷孕次數是否可能增加第一年內需要治療的風險，Silverstein醫師與其同事收集了來自器官共享聯合網絡（UNOS）資料庫的數據，從1995年的第一次移植，到2006年的數據，對象是16歲以上的病患，他們發現2,644位有排斥反應與過去懷孕過的女性，以及10,172位男性的排斥數據。
作者們使用卡方檢定以評估懷孕次數與排斥反應及性別之間的關係，並且使用多變項邏輯式迴歸分析評估預測排斥反應的懷孕次數。
當針對懷孕次數與排斥病患的比例進行分析時，他們發現這之間有顯著的線性關係，未曾生產過的女性幾乎沒有風險，而懷孕超過五次以上的女性風險最高（X2=22.9；P=0.0008）。
在分析排斥反應與性別之間的關係時，研究團隊發現，雖然有女性排斥反應風險較高的趨勢，但男性與未曾懷孕女性之間沒有顯著差異。
Silverstein醫師表示，我們懷疑，但無法確認，這可能代表某些懷孕次數是沒有說出來的，相較於孩子的數目。
在一項針對536位女性懷孕數目的第二型PRA分析中，研究團隊發現抗體數目與懷孕次數有很強的關聯（X2=29.7；P=0.003）。
在邏輯式迴歸分析中，排斥反應唯一顯著的危險因子，除了PRA升高外，是懷孕次數超過五次以上，這顯著與在移植第一年結束前需要治療排斥反應的風險上升兩倍有關（勝算比為2.224；95%信賴區間為1.031-4.796）。
Silverstein醫師承認，這項研究因為未能收集完整數據，以及該資料庫並未包括存活少於275天病患的資料，代表研究團隊不能分析任何有關急性排斥反應或是早期不良預後的資料。
研究座談會引言人Stuart D. Russell醫師向Medscape移植學表示，毫無疑問的，前敏感化作用與抗體隨著懷孕次數增加。Russel醫師是巴爾的摩約翰霍普金斯大學心臟衰竭與移植醫學教授與臨床主任，他並未參與這項研究。
吸引我和其他人的是，這裡有另一篇文獻顯示罹患生產後心臟病變病患的死亡率，在五年時顯著較低，主要的原因是順應性不佳。以UNOS資料庫給我們帶來的警訊，讓我們懷疑可能有一群女性正面臨災難性的情況，因為可能有與順應性有關的議題，以及他們已經敏感化，且處於高風險。
Silverstein醫師與Russell醫師表示沒有相關資金上的往來。
ISHLT 2009: Five or More Pregnancies Increase Risk for Heart-Graft Rejection in First Year
By Neil Osterweil
Medscape Medical News
April 28, 2009 (Paris, France) — Having 5 or more children might put a woman at risk for shortened survival if she later needs a heart transplant, according to new research presented here at the International Society for Heart and Lung Transplantation 29th Annual Meeting and Scientific Sessions.
"Pregnancy may represent an independent risk factor for yearly acute rejection risk," said lead investigator Cheri Silverstein, MD, a clinical research fellow in the Division of Cardiovascular Medicine at Vanderbilt University in Nashville, Tennessee.
The risk for rejection appears to be independent of sensitization to fetal antigens, Dr. Silverstein said.
Women who undergo orthotopic heart transplantation appear to be at increased risk for rejection, compared with men, Dr. Silverstein said, and smaller studies have suggested that a history of pregnancy in general, and 2 or more pregnancies in particular, puts women at increased risk for elevated panel reactive antibodies (PRA), a marker for rejection.
To determine whether cumulative pregnancies might increase the risk for rejection requiring treatment within the first year, Dr. Silverstein and colleagues gathered data from the United Network for Organ Sharing (UNOS) database on all first transplants from 1995 to 2006 in patients 16 years and older. They found data on rejection and prior pregnancy for 2644 women, and compared the information with data on rejection for 10,172 men.
The authors used chi-square testing to evaluate the relation between the number of pregnancies and sex with rejection, and multivariate logistic regression analysis to assess the ability of the number of pregnancies to predict rejection.
When they looked at the fraction of patients with rejection by number of pregnancies, they found a clear and significant linear relationship, with nulliparous women having virtually no risk, and women with 5 or more pregnancies being at the highest risk (χ2?= 22.9; P?= .0008).
In an analysis of rejection by sex, the investigators found that there was no significant difference between men and women who had never been pregnant, although there appeared to be a trend toward a higher fraction of women with rejection.
"We suspect, but we can't determine, that this may represent some underreporting of pregnancies, as opposed to number of children," Dr. Silverstein said.
In an analysis of class?II PRA by pregnancy number in 536 women, reserachers found a strong correlation with higher numbers of antibodies and higher numbers of pregnancies (χ2?= 29.7; P?= .003).
In logistic regression analysis, the only significant risk factor for rejection, other than elevated PRA, was 5 or more pregnancies, which was associated with a more than 2-fold risk for rejection requiring treatment in the first year (odds ratio, 2.224; 95% confidence interval, 1.031 - 4.796).
Dr. Silverstein acknowledged that the study was limited by missing data and the fact that the database did not contain information about patients surviving less than 275 days, meaning that the investigators could not analyze any data about hyperacute rejections or early adverse outcomes.
"There's no question that the incidence of presensitization and antibodies goes up with pregnancy," Stuart D. Russell, MD, moderator of the session in which the study was presented, told Medscape Transplantation. Dr. Russell, associate professor of medicine and clinical chief of heart failure and transplantation at Johns Hopkins University in Baltimore, Md, was not involved in the study.
"What's intriguing to me and to others is that there was another paper presented here [that showed that] mortality among patients with peripartum cardiomyopathy was significantly lower at 5 years, with the primary reason being noncompliance. With all the caveats of the UNOS dataset, it makes one wonder whether there might be a group of young women who get into a disastrous situation, and because of that, they may have issues with compliance, as well as the fact that they're presensitized and, by that fact alone, are at increased risk."
Dr. Silverstein and Dr. Russell have disclosed no relevant financial relationships.
International Society for Heart and Lung Transplantation (ISHLT) 29th Annual Meeting and Scientific Sessions: Abstract 568. Presented April 24, 2009. |
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