Cotrimoxazole is effective as primary prophylaxis for toxoplasmic encephalitis in HIV-infected patients: a case control study

Update on the hyper immunoglobulin M syndromes

The Hyper-immunoglobulin M syndromes (HIGM) are a heterogeneous group of genetic disorders resulting in defects of immunoglobulin class switch recombination (CSR), with or without defects of somatic hypermutation (SHM). They can be classified as defects of signalling through CD40 causing both a humoral immunodeficiency and a susceptibility to opportunistic infections, or intrinsic defects in B cells of the mechanism of CSR resulting in a pure humoral immunodeficiency. A HIGM picture can also be seen as part of generalized defects of DNA repair and in antibody deficiency syndromes, such as common variable immunodeficiency. CD40 signalling defects may require corrective therapy with bone marrow transplantation. Gene therapy, a potential curative approach in the future, currently remains a distant prospect. Those with a defective CSR mechanism generally do well on immunologoblulin replacement therapy. Complications may include autoimmunity, lymphoid hyperplasia and, in some cases, a predisposition to lymphoid malignancy.

The use of donor and recipient screening for toxoplasma in the era of universal trimethoprim sulfamethoxazole prophylaxis

BACKGROUND

Toxoplasmosis is a serious complication of solid organ transplantation. The highest risk of infection and disease occurs in heart recipients with primary infection transmitted by a seropositive donor to a seronegative recipient (donor-recipient mismatch). Toxoplasmosis has been reported to occur in noncardiac transplant recipients; however, no large studies examining the frequency of such events or the need for serologic screening exist.

METHODS

A retrospective cohort study of 1,006 solid organ transplant recipients transplanted in our center between 1984 and 1997 was performed to examine the incidence of Toxoplasma seroconversion, reactivation, and clinical toxoplasmosis and to evaluate the impact of trimethoprim sulfamethoxazole (TMP/SMX) prophylaxis on these outcomes.

RESULTS

Pretransplant Toxoplasma seroprevalence was 13.4% in donors and 17.8% in recipients. The incidence of Toxoplasma donor-recipient mismatch was 9.5% during the 14-year study period, and only 39.1% of mismatched recipients received TMP/SMX prophylaxis. Only four patients seroconverted, of whom two had received prophylaxis. There were no cases of clinical disease; either primary or reactivation.

CONCLUSIONS

We therefore conclude that in transplant centers with low Toxoplasma seroprevalence, routine screening for Toxoplasma in solid organ donors and recipients is not necessary, particularly in the era of routine TMP/SMX prophylaxis.

Adverse reactions to cotrimoxazole in HIV-infected patients: predictive factors and subsequent HIV disease progression

The relationship between the onset of adverse events to cotrimoxazole in HIV-infected patients and the subsequent development of toxoplasmosis, other AIDS-defining events and survival was studied in 592 French patients who first received cotrimoxazole during the Delta trial. Low CD4+ cell count at cotrimoxazole introduction was the only factor associated with the onset of adverse reactions. The occurrence of toxoplasmosis and first AIDS-defining events were significantly and independently linked to a low CD4+ cell count at cotrimoxazole introduction (p < 0.0001) and to previous cotrimoxazole withdrawal for adverse events (p = 0.004 and p < 0.0001, respectively), but not to previous cotrimoxazole withdrawal for reasons other than adverse events, as compared to patients who did not discontinue taking cotrimoxazole during this survey. The survival rate was significantly shorter among both patients who stopped taking cotrimoxazole for adverse events and for other reasons (p = 0.03 and p = 0.0001, respectively), as compared to patients who continued to take cotrimoxazole.

Incidence and risk factors for toxoplasmic encephalitis in human immunodeficiency virus-infected patients before and during the highly active antiretroviral therapy era

The occurrence of toxoplasmic encephalitis (TE) was studied among 19,598 and 17,016 patients enrolled in the French Hospital Database on human immunodeficiency virus whose CD4 cell counts decreased to < or =200x10(6) cells/L before (1992-1995) or after (1996-1998) the availability of highly active antiretroviral therapy, respectively. The incidence of TE decreased from 3.9 cases per 100 person-years in the first period (95% confidence interval [CI], 3.7-4.1) to 1.0 cases per 100 person-years in the second period (95% CI, 0.9-1.1). After adjustment for known risk factors for TE, patients who received cotrimoxazole prophylaxis had a lower risk of TE (adjusted relative hazard, 0.6 and 0.5, respectively, for the first and second periods; P < .001). For patients treated with cotrimoxazole at inclusion, discontinuation of cotrimoxazole increased the risk of TE in both periods (adjusted relative hazard, 4.8 and 4.2, respectively; P < .001). Among patients whose CD4 cell counts increased to > 200 x 10(6) cells/L while undergoing highly active antiretroviral therapy, the incidence of TE was 0.1 cases per 100 person-years (95% CI, 0.0-0.2) and was not increased by discontinuation of cotrimoxazole.

Primary prevention with cotrimoxazole for HIV-1-infected adults: results of the pilot study in Dakar, Senegal

OBJECTIVES

To assess the efficacy and tolerance of chemoprophylaxis with cotrimoxazole compared with placebo among HIV-1-infected adults.

DESIGN

Randomized, double-blind, placebo-controlled clinical trial in the urban community of Dakar, Senegal.

METHODS

Eligibility criteria were age greater than 15 years, HIV-1 or HIV-1 and HIV-2 dual seropositivity, CD4 cell count lower than 400 copies/mm3, no progressive infection, no previous history of intolerance to sulphonamide, lack of severe anemia or neutropenia, and renal or hepatic failure. Written informed consent was obtained. Recruited patients received 80 mg of trimethoprim and 400 mg of sulphamethoxazole daily or a matching placebo. The main outcomes were survival and the occurrence of clinical events defined as Pneumocystis carinii pneumonia, cerebral toxoplasmosis, bacterial pneumonia, infectious enteritis, bacterial meningitis, urinary tract infection, bacterial otitis and sinusitis, and pyomyositis.

RESULTS

Between September 1996 and March 1998, 297 patients were screened, and 100 were randomized in the study. Demographic, clinical, and biological characteristics of the two groups were similar as was the mean length of follow-up (7.7 months for the cotrimoxazole group vs. 8.0 months for the placebo group). There was no significant difference between the two groups in survival (hazard ratio = 0.84; 95% confidence interval [CI]: 0.36-1.94) in the probability of severe event occurrence, defined as death or hospital admission (hazard ratio = 1.10; 95% CI: 0.57-2.13), or in the probability of clinical event occurrence (hazard ratio = 1.19; 95% CI: 0.55-2.59). Adjustment for initial CD4 cell count did not change these results. A low dose of cotrimoxazole was tolerated well clinically as well as biologically; only one treatment interruption occurred as the result of a moderate cutaneous eruption (grade 2).

CONCLUSION

Our study does not show a beneficial effect of chemoprophylaxis with low-dose cotrimoxazole on survival or occurrence of opportunistic or nonopportunistic infections for HIV-1-infected patients in Dakar, Senegal.