Relative knowledge point and result analysis
PCP has a peculiar onset, and it progresses rapidly yet costly, as well as gives life-threatening complication. Clinicians should be highly aware of such complications. If early diagnosis and proper treatment are performed then the prognosis remains good in the renal transplantation recipients. Experience has shown that early and accurate diagnosis of PCP gives advantages upon the outcome and results in minimizing the toxicity associated with the therapy.
Clinical manifestations were typical, but it is difficult to find pathogens
In adult renal transplant recipients, the period time with maximum susceptibility to this infection can be predicted with reasonable accuracy which was 2-6 months after transplantation. This is due to the high dose of the immunosuppressant consumption at the early period after transplantation. It was also easily understood that there was wide variations in the rate of occurrence of PCP in renal transplantation recipients among transplant centers.
Initial diagnosis of PCP was usually based on symptoms and chest radiography. The best diagnosis of PCP is achieved by detecting the appearance of organism in the induced sputum or bronchoalveolar lavage fluid through tinctorial staining or polymerase chain reaction, and lung biopsy through fiber bronchoscopy. Pneumocystis pathogen detection is difficult to perform and time consuming. Once the patient develops a mild to moderate fever and short breath after exertion with a non-productive cough at early period of post-renal transplantation, clinicians should be highly aware of such complications. Given the detection of pathogens can be carried out empirically, if there was no timely intervention, then there will be a rapid progressive phase, with severe hypoxia and dyspnea developed within 5 to 10 days of initial manifestations.
The chest radiograph was abnormal in more than 90% of patients and changed very quickly during the course of the therapy with PCP. Based on our observations, the most common finding was a diffuse increase in interstitial and alveolar markings (commonly called ground glass change), focal infiltrates, nodules and even cavities or pneumatoceles[7]. Several reports suggest that the appearance of pulmonary infiltrates might be delayed and paused after the abrupt onset of dyspnea. The CT scan could clearly show detail changes of the lung and might increase the accuracy of the earlier PCP diagnosis. The peripheral leukocyte count increased as well as the renal and hepatic function tests were usually normal. Blood gases showed hypoxemia.
PCP diagnosis
①Cases had definite immunosuppression history. ②Imaging manifestation. ③Compound sulfamethoxazole treatment was effective. ④Pneumocystis carinii was found in pathogen detection. The cases were diagnosed PCP if consistent with the preceding 3 or all of features.
PCP treatment
①Some scholars thought that PCP would spread among renal transplant recipients, and the patients should be separated from others[8]. However, we found that there were no signs of infection in the hospital, so it is unnecessary to isolating strictly. ②If the fingers oxygen level sustained below 85%, mechanical ventilation were required. ③Adjustments of immunosuppressant are a key step to cure the disease, reduction or discontinuation of the immunosuppressant must be done immediately. At the early phase, administration of the agents to improve the immune level should be conducted. This can block the progress of the disease. ④Anti-pneumocystic medication is used with concomitant steroids in order to avoid inflammation. Studies have shown that patients with the addition of steroids suffered less respiratory failure, and it also lowers patient’s mortality rate as well as shorten the patient's recovery time compared to the non-use group. The commonly used dosage was: methylprednisolone 80-120 mg intravenously for daily or three times a week. ⑤Support treatment: Parenteral nutrition would be used if necessary, such as injection of γ-globulin or subcutaneous injection of thymopetidum to increase patients’ immunity. ⑥If the patients complicated by bacterial, fungal or viral infection, and then an appropriate targeted therapy should be given.
TMP/SMZ was the first choice of drugs for both treatment and prophylaxis of PCP[6, 9-13]. The usual dose for the treatment with TMP/SMZ was 60-100 mg/kg per day, with every 6 hours for a period of about 21 days. The adverse reaction of the TMP/SMZ was always few and mild, mainly included nausea, vomiting, liver dysfunction, neutropenia, fever, itching, and skin rash. The drug was excreted through kidneys and might possibly produce crystallization in the kidneys when high amount of dosage was taken[14]. This might cause long term renal damage. An appropriate administration of diuretic and sodium bicarbonate injection may protect the inter-gender renal allograft during the therapy. If some patients were unable to tolerate this treatment, other drugs could be used, including a combination of primaquine and clindamycin, pentamidine, atovaquone, and a combination of dapsone and trimethoprim[15].
PCP precaution in renal transplantation recipients
PCP can be prevented exceed more than 95 percent of renal transplantation recipients by TMP/SMZ (480 mg or 960 mg per day)[1, 10, 11, 16-18]. The KDIGO recommended that the renal transplantation recipients should be on PCP prophylaxis for at least the first 6 months post transplantation[11-12,18], and the protocol also can be effective in preventing urinary tract infection[14]; cytomegalovirus is a frequent and important cause of clinical disease in renal transplantation patients, in addition to directly attributable morbidity, cytomegalovirus may also have an immunomodulatory effect, which associated with infectious complications as well as acute rejection, so prophylaxis of cytomegalovirus is also recommended at least 3 months after transplantation, with ganciclovir or valganciclovir[16].
Bias or limitation of this study
This was a retrospective trail, and no control group was established.
Clinical application significance
The PCP after renal transplant is life threatening, the primary cause is excessive immune suppression; individualized immunosuppression regime can reduce the incidences of opportunistic infections. The doctors who care the renal transplant patient need close monitor the patients, and prevent first, even if the PCP occurred, they be found and treatment timely to avoid serious consequences. Prophylaxis with TMP/SMZ is safe and efficacy[19-20].
