Pediatrics, Faculty of Medicine, Ain Shams University, P.B. 11381, Abbassia Square, Cairo, Egypt.
Infection. 2012 Jun;40(3):279-84. doi: 10.1007/s15010-011-0230-5. Epub 2011 Dec 22.
Cryptosporidium species is considered to be an important cause of significant morbidity in immunocompromised individuals. A prospective case-control study of sporadic diarrhea due to Cryptosporidium infection was conducted on children with acute lymphoblastic leukemia (ALL).
Forty children with ALL on maintenance chemotherapy according to the Berlin-Frankfurt-Munster (BFM-90) protocol and 45 sex- and age-matched controls were studied. The ALL group included 25 patients with acute diarrhea and 15 without diarrhea, and the control group included 30 children with acute diarrhea and 15 without. Collected stool specimens were examined using modified Ziehl-Neelsen (MZN) and modified trichrome stains. Serum Cryptosporidium Parvum immunoglobulin G (IgG) antibodies were detected by enzyme-linked immunosorbent assay.
Cryptosporidium oocysts, pathogenic Gram-negative organisms, Giardia lamblia, and Entamoeba histolytica were identified in the stool samples (fecal specimens) of six (24%), eight (32%), four (16%), and two (8%), respectively, of the 25 patients with ALL and actute diarrhea and in one (3%), two (6.5%), six (20%), and five (16.5%), respectively, of the 30 control patients with diarrhea. Serum IgG antibodies were positive in four of the six ALL patients and in one of the control group patients with Cryptosporidium diarrhea who tested positive for oocysts in the stool. Diarrhea duration and severity were greater in ALL patients with stool-positive Cryptosporidium oocysts than in those with non-Cryptosporidium-positive diarrhea (p < 0.000).
Cryptosporidium infection should be considered in children with ALL presenting with prolonged or severe watery diarrhea during chemotherapy, especially those treated with methotrexate and 6-mercaptopurine. Since Cryptosporidium is not routinely tested for in stool examination, a MZN stain is recommended.
隐孢子虫被认为是免疫功能低下个体发生严重疾病的重要原因。对急性淋巴细胞白血病（ALL）患儿的散发性隐孢子虫感染性腹泻进行了一项前瞻性病例对照研究。
根据柏林-法兰克福-明斯特（BFM-90）方案，对 40 名接受维持化疗的 ALL 患儿和 45 名性别和年龄匹配的对照者进行了研究。ALL 组包括 25 例急性腹泻患儿和 15 例无腹泻患儿，对照组包括 30 例急性腹泻患儿和 15 例无腹泻患儿。采集粪便标本，用改良齐氏染色（MZN）和改良三色染色法检查。采用酶联免疫吸附试验检测血清隐孢子虫细小病毒 IgG 抗体。
25 例 ALL 合并急性腹泻患儿的粪便标本中，6 例（24%）鉴定出隐孢子虫卵囊、致病性革兰阴性菌、蓝氏贾第鞭毛虫和溶组织内阿米巴，30 例腹泻对照患儿中，1 例（3%）、2 例（6.5%）、6 例（20%）和 5 例（16.5%）分别鉴定出上述病原体。6 例粪便隐孢子虫卵囊阳性的 ALL 患儿和 1 例粪便隐孢子虫卵囊阳性的对照组患儿血清 IgG 抗体阳性。粪便隐孢子虫卵囊阳性的 ALL 患儿腹泻持续时间和严重程度大于粪便隐孢子虫阴性的腹泻患儿（p<0.000）。
在接受化疗的 ALL 患儿中，如果出现长时间或严重的水样腹泻，尤其是接受甲氨蝶呤和 6-巯基嘌呤治疗的患儿，应考虑隐孢子虫感染。由于粪便检查通常不检测隐孢子虫，因此推荐使用 MZN 染色。
